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CONSTRUCTION TECHNOLOGY AND PRACTICES RCC Frame, Walls(Cast in
Situ)Pre-cast, Pre-Fab and Pre-Stressed Modular ConstructionBy
N.KRISHNAM RAJUADVISOR TO APHB
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A :INTRODUCTION OF CIVIL ENGG. CONCEPTS AND GOOD CONSTRUCTIONS
PRACTICES
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Generally Building construction is classified as
Load BearingRCC FramedStructure
What is a Project ?
In simple term project is one temporary activity with a clear
start and a end
The main elements are
TimeCostResourcesClear roles and responsibilityDelivery
Detailed Design :
Develop detailed design from approved scheme design.Detailed
design will confirm type of construction, quality of materials and
standard of workmanship.
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Specifications :
Prepare detailed information including Drawing
SchedulesSpecification of MaterialsWorkmanship
Design :
Evaluation of design requirementsReview of compatibility of the
design with the plan and budget.Identification of design
objectives, design stages, activities and elements.Regular
Monitoring of the design development.Identification of proposed
design changes and their resolution.Assessment of design progress
related to the design schedule.Evaluation of as to the completeness
of construction information.Review of sample materials and mock ups
for compliance with specifications.Identification and arrangement
of the final standard of acceptance of the construction..
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Civil Engineering Comprises of
PlanningDesignConstructionQuality Control.
The Main components of Buildings are :
1. Earth Work : Excavation of Foundation. Filling in
FoundationFilling in Basement.Open and Pile Foundation2. Section :
Concrete3. Section : Brick masonry / Stone masonry 4. Section :
Flooring5. Section : Roofing and Ceiling 6. Section : Plastering,
Painting.7. Section : Wood Work8. Section : Structural Steel
Work.9. Plumbing Services.10.Miscellanies.
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CONCRETE
Grades : The Concrete shall be designated as follows :Group
Grade (1) (2) Ordinary M 10 Concrete M 15 M 20 Standard Concrete
M25, M 55 High Strength M60, M 65 Concrete M 70, M 75, M 80Note :
In the Designation of Concrete M refer to mix and the number to
specify compressive strength of 150 MM size cube at 28 days
expressed as N/mm2
Workability Of concrete:
The concrete mix proportion chosen should be such that the
concrete is of adequate workability for the placing condition of
concrete and can be properly compacted.
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Durability of Concrete :The materials and mix proportion
specified and used should be such as to maintain in integrity to
protect embedded steel from corrosion. One of the main
characteristics Influencing the durability of concrete is the
permeability to the ingress of Water, Oxygen, Carbon Dioxide and
Other Deleterious Substances. Impermeability is governed by the
constituent and workability used in making the concrete.
Factors Influencing Durability :(a) Environment (b) Cover to
embedded steel(c) Type and quality of material used(d) Cement
content / W.C.R. of concrete(e) Workmanship to obtain full
compaction and efficient curing (f) Shape and size of the
member
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Exposure Condition:(1) Mild(2) Moderate(3) Severe(4) Vary
Severe(5) Extreme
Production of Concrete :
Quality assurance measures are both technical and
organizational. The job of quality control and quality assurance
would involve quality audit of both inputs as well as outputs.
Inputs OutputsMaterial for Concrete Concrete in PlaceWorkmanship in
allStages of Batching, Mixing,Transportation, Placing, Compaction,
Curing etc.,
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Batching :In Batching Concrete, quantity of both cement and
aggregates shall be determined by mass.
R.M.C, :As per IS 4926Volume batching may be allowed only where
weigh batching is not practical.Form Work : (1)The form work shall
be designed and constructed so as to Remain sufficiently rigid
during placing and compaction of Concrete and to prevent loss of
slurry from the concrete.(2)For details regarding design, detailing
etc., reference may be as per IS 14687(3) Cleaning and treatment of
form workThe face of form work in contact with concrete shall be
cleaned and treated with form release agent.(4) Stripping timeForm
shall not be released until the concrete has achieved a strength of
at least twice the stress to which the concrete may be subjected at
the time of removal form work. Details may be as per IS 456
2000.
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Assembly of Reinforcement: Reinforcement shall be bent and fixed
in accordance with procedure (specified in IS 2502) Bar bending
schedule shall be prepared for all reinforcement work.
Reinforcement shall be placed and maintained in the position shown
in the drawings by providing proper cover blocks, spaces,
supporting bars etc.,
Welded Joints: In reinforcement may be used in accordance with
IS 2751 and IS 9417.
Placing Compaction :
The concrete shall be placed and compacted before initial
setting of concrete commences and shall not be subsequently
disturbed. Concrete shall be compacted using mechanical vibration
complying with IS 2505, IS 2506, IS 2514 and IS 4656. Over
vibration and under vibration of concrete are harmful and should be
avoided.
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Foundations :
Excavation of Foundations :
1Fix up centre line Plugs.2Construct centre line pillars.3Fix up
the basement height 4.Depth of Foundation, Fix up the top of
concrete footing5.Pedestals shall be constructed duly marking their
position. 6.Excavation for foundation shall be to the exact
dimensions as specified.7.Based on the soil profiles sides of
excavation can be maintained.8.The bed of excavation shall be
dressed level and rendered firm by watering and tamping.9.The
foundation excavation shall be inspected by the competent Engineer
before the concrete is laid.
Excavation in Rock :
1.Excavation in rock shall be carried by crow bars, pick exe or
pneumatic drills etc., Unless permitted blasting shall not be
resorted to.
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Filling in Foundations :
1.Earth used for back filling shall be free from salts, organic
or other deleterious matter.
2.As soon as the construction of foundation has been completed,
the space : all round the foundations shall be cleared of all
debris and filled with earth is layers not exceeding 150mm, laid
care being taken not to disturb the constructed foundation, the
back fill shall be brought to the original ground surface.
3.On completion of the structure, the ground shall be carefully
dressed with a gentle outward slope for a distance of 3 meters,
all-round the structure.
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Filling in Basement :
1.The earth or sand for filling in basement shall be of approved
quality and free organic or other deleterious matter.
2.Expansive soils shall not be used, sea sand also shall not be
used unless permitted.
3.The surface to receive the filling shall be first cleared.,
free from all roots, Vegetation of or spoil and welted.
4.Filling shall be done in layers not exceeding 150 mm, each
layer being watered and competed before the succeeding layer is
laid.Care being taken not to disturb the structure. The finished
level of filling shal be to the bottom of the base concrete of the
flooring.
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CONSTRUCTION PRACTICESMaterials
CementO.P.C cofrom to 33 grade IS - 269 43 grade - IS - 8112 53
grade IS - 12269P.P.C confirm to IS - 1489Unless otherwise
specified cement shall mean OPCCement shall be stored in dry,
weather proof godownsCement which has became caked or otherwise
damaged shall on no account be used on the work.
Expansive soils shall not be used.
Filling shall be done in layers not exceeding 150 mm, each layer
being watered and compacted before the next layer in laid,. The
finished level of filling shall be to the bottom of base concrete
of flooring
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CONSTRUCTION PRACTICESSand
Shall comply with the requirement of IS 383Granual material ie
processing of storeNatural sand resulting from natural
disintegration of rock which has been depositedCrushed stone sand
(produced by crushing of hard stone)Coarse sand F.M of course sand
not less than 2.5Fine sand F.M of fine sand not less than 1.0Sieve
analysis to be conducted before use.Sand shall be obtained from the
source specified by the engineer in charge.Sand which is chemically
reacting with alkalis of cement is harmful as cracking of concrete
may taken place shall be prohibited.Sand shall be screened and
should be free from dirty and must be washed in cleaned water
before use.The percentage of silt content to be determined as per
the procedure laid down.
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CONSTRUCTION PRACTICESCoarse aggregate
Shall comply with the requirement of IS-383Coarse aggregate
should be graded sizes well distributed between the nominal size
and lower limit for coarse aggregate.Aggregate shall be obtain from
the quarries specified by the dept.Crushed stone shall unless
otherwise specified, consists of hard, sharp, angular pieces,
crushed to specified sizes. Flaky and weathered stones shall not be
used..Coarse aggregate shall be free from all dust and dirt and
shall not contain any harmful material such as iron, pirals, coal,
mica, shale etc.Quartz which has a smooth surface that adhesion of
the mortar is poor and not suitable as an aggregate unless
specifically passed after laboratory test.Size and grading shall be
as per the requirement.Testing shall be in accordance with IS
2386h
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CONSTRUCTION PRACTICESWater
Water used for mixing mortar or concrete and for curing shall be
clean and free from injurials amounts of deleterials materials such
as oils, acids, salts, silts and organic matter.
PH value of water shall not be less than 6 conforming to IS code
3025
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CONSTRUCTION PRACTICESCentering
Use rigid form work.Centering plates, planks or plywood to be
properly cleaned.Shuttering to be checked in stages.Beams bottom-
allignment & level and rigidity.Beam sidesSlab shuttering and
levels to be ensured.Fixing of side support cross strutting etc.,
for rigidity.
Provide extra supports at joints at beam bottoms etc.Prove care
to be taken to prevent bulging of centering.Centering to be
approved by competent authority before laying concrete.Care to be
taken, not to damage the concrete while removing centering.After
de-shuttering, the materials are to be properly stacked and
cleaned.Time of removal of centering after laying concrete.Walls,
columns and vertical side of beams - 24 to 48 hrsSlabs 7 daysBeam
upto 6 m spans 14 daysBeams over 6 m spans 21 days.
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CONSTRUCTION PRACTICESReinforcementReinforcement steel to be
obtained from IS standard main manufacturers only.No re-rolled
steel is to be used, steel to be tested and test certificates to be
obtained.Ensure reinforcement bars are clean, free from dust at the
time of placing.Fabrication of bars is to be done in cold.Vertical
distance between the successive layers of bars in members are to be
maintained with spacers.Check reinforcement for size, spacing,
location, numbers, overlaps, hooks etc., as per bending
schedule.Ensure staged overlaps and anchorage, wherever
needed.Ensure reinforcement is kept in position by chairs etc.,
during placing and compaction of concrete.Ensure proper placement
of cover blocks.Ensure before placing the concrete, the
reinforcement is in position, undisturbed.Ensure proper binding of
reinforcementEnsure that the lap joints of bars are
staggered.Ensure 20 mm cover for slabs25 mm cover for beams and
columns with 12 mm dia rods.40 mm cover for beams and columns with
over 12mm dia rods.
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CONSTRUCTION PRACTICES
Placing of concrete (As per clause No. 13.2 of IS 456/2000)
Design mix to be obtained.
The concrete to be deposited as nearly as practicable in its
final position.
Avoid lengthy handling and segregation of mix.
The concrete shall be placed and compacted before initial
setting of concrete.
Avoid segregation or displacement of reinforcement form
work.
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CONSTRUCTION PRACTICES
Compaction (As per clause No. 13.2 of IS.456/2000)
Concrete to be compacted with pan vibrators for slabs and pin
vibrators for beams/columns
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CONSTRUCTION PRACTICES
Slump Test (As per clause No. 13.2 of IS 456/2000)
For concreting of lightly reinforced sections, mass concreting
with very low and low degree of workability, the slump is to be
between 25 to 75 mm.
For concreting with heavily reinforced sections with medium
degree of workability the slump is to be between 50 to 100 or 75 to
100 as directed by Engineer-in-charge.
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CONSTRUCTION PRACTICESStone masonry
Coursed rubble stone masonryThe face stones shall be squared on
all joints with beds horizontal.They shall be set in regular
courses of uniform thickness fom bottom to top throughout.No face
stone shall be less width in plan than 150 mm for walls of 400 mm
thick 200 mm for walls of 450 mm thick and 250 mm for walls of 600
mm thick and above.The face stones shall be laid headers and
stretchers alternatively so as to break joints.The stones shall be
solidly bedded, set in full mortar with joints not exceeding 12mm
and extend back into the hearting.The height of the stone shall not
exceed breadth at face nor the length inwards.
Through stones and HeadersIn all the works up to a width of
600mm, bond stones running though the wall to be provided at an
intervals of 2 m in each course.For walls thicker than 600mm, a
line of headers each headers each header overlapping by 150mm
minimum shall be provided from front to back at 2 m intervals in
each course.The position of the stones shall be marked on both the
faces.
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CONSTRUCTION PRACTICESBrick work
The thickness of joints in case of masonry with first class
brigcks shall not be more than 10mm.In case of masonry with second
class bricks joints shall not be more than 12 mm.The bricks shall
be thoroughly soaked in clean water.The cessation of bubbles when
the bricks are immersed in water is an indication of thorough
soaking of bricks.The bricks shall be laid with joints full of
mortar.The face joints shall be racked by jacking tool when the
mortar is green.The wall construction shall be taken up truly
plumb.All courses shall be laid truly horizontal.All vertical
joints shall be truly vertical.The thickness of brick course shall
be kept uniform and with their frogs kept upward.
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CONSTRUCTION PRACTICESPlastering
Water the brick wall before start of plastering.Chicken mesh at
joints of brick wall and R.C.C member to be provided. Dry mixing of
cement and sand is to be done on impervious platform.Holes provided
for scaffolding are to be closed along with plastering.Level
marking must be done in advance form time to time.Chip off concrete
surface before starting plastering.Gaps around door window frames
to be filled.Base coat of plaster to be checked before application
of finishing coat.
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SUMMARY OF QUALITY CHECKS TO BE DONE ON BULLDINGS WORKS.
Bearing capacity of soil to be checked in advance.Material to be
approved in advance.Quality of materials to be checked
periodically.Steel to be obtained from main manufacturers only.Size
of footings, pedestals, columns, beams are to be checked.Design
mixes to be obtained in advance.Cover to the reinforcement as per
structural requirement to be checked. Thickness of plastering to
wall be checked.Proportion, workability and vibration of CC mix and
cement mortar proportion be checked.Cube samples be collected for
testing in lab.
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DETAILING OF FOOTINGS
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DESIGN & CONSTRUCTION OF BRIDGESA.Bridge is a structure
having a total length above 6 M for carrying traffic or other loads
over a channel, road or railoroy (IRC 5-8988)Minor Bridge : Length
up to 60 MMajor Bridge : Length above 60 M.
B.Selection of SiteNarrow width of channel Cross section having
large average depth Straight reach of the channel. Advance of
curves in approaches.
C.Hydraulic Data Size, shape and surface characteristics of
catchment Storage areas in catchment. Hydrographs. HFC, LWL, Period
of HFL observed Max, Depth of Scour. Type of river i.e., seasonal
or perennial.
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d)Sub Surface dataThe economical design of a bridge depends
mainly on subsurface profile. Properties of soil/rock Type of rock,
structure of rock Ground water level Scour, quality of water in
contact with Suitable foundation level, S.B.C. Possible
settlements.
e)Design discharge and linear water way (LWW) to be worked out
as per codal practices.
f)Scour depth and afflux
g)Width of carriage way, footpath and median
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IISubstructure and foundationsTypes of foundation are 1) Shallow
2) Deep TypeFoundation depends upon soil strata met with and
SBC.
IIICaissons / Well Foundations.The caissons are advantages
when1) Substrata contains large boulders.2) Foundation is subjected
to large lateral forces.3) Massive substructure is required to
extend to well below the river bed against over turning, scour
etc.,The main components of caisson (well) are
1) Cutting edge 2) Well curb 3) Staining. 4) Bottom Plug 5) Top
Plug 6) Well cap 7) Filling the wells.The wells can be singular
circular / Two circular or double D Rectangular.
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IV Pile Foundations Bridge on Land River BridgeDriven Cast in
situ piles 0.5 M 1.20 MPre-cast Piles 0.35 M 1.00 MBored Piles 1.00
M 1.20 MSpacing of Piles not less then 3 times dia of pile capacity
of pile may be arrived from the soil properties and formula as per
IS 2911.
V. Dept of Foundation :Foundation shall be taken to such depth
that they are safe against scour or protection from it.
Sub Structure /Supporting Structures.
Abutments : To withstand earth pressure may be solid wall type
or spill through type. Abutment Plier : May be provided at location
where there may be need for increasing water way
subsequently.Pliers : Pliers may be PSC / RCC / PCC.Dirt walls,
Wing Walls, Return Walls.
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Bearings :
1.Bearing is a point of connection between structure and the
support designed to transmit vertical and horizontal loads and
allow for rotation and horizontal loads and allow for rotation and
horizontal movement.
2.Bearings may be fixed type, sliding, rolling type, also may be
metallic, rubber (Neoprene ) or synthetic rubber.
3.Bearings rests on bearing pedestal over pier
Super Structure :May be : RCCPre-stressed
ConcreteSteelMasonryComposite Construction using steel and
RCC/PSE
The Super Structures :Is to be designed for 70 R Loading and
other cross loads as per IRC 6-2000.
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Segmental Deck Construction : Cantilever construction is a
method of progress the construction of Cantilever in segment and
stitching them to the segments already completed by pre-stressing
the segments, size normally is 2.5 M to 3.0M and they can be either
pre-cast or cast in situ on traveling gantries.
The pre-cast units are erected by launching truss or floating
crane.
Parapet & Railing Crash barrier.
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Guide Lines for Road ConstructionRoad Features1. Alignment :
Topographical and Geological features.2. Environmental factors:Air
pollution to life system, stream pollutions, drainage pattern, land
scoping etc.,3. Proposal of right way acquisition of structures.4.
Traffic:Present and projected for a period of ten years for up
gradation of work estimated traffic for new construction.5. Road
design and Specification.:Geometric design of road, pavement
design, retaing works, specifications.6. Cross drainage
Structures:Investigation, details of design proposal, drawings of
C.D. Works.7. Material Labour are Equipment:Availability,
suitability, lead distance mobilization of resources.
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8.Rates : Schedule of rates adopted analyses price escalation
etc., 9.Construction Programme:Likely period of execution,
constraints on the works. 10. Miscellaneous :Diversion of traffic
arrangement of water supply and other site amenities etc.,11. Lard
acquisition etc.
Classification of Roads :1. National High Ways2. State High Ways
(SH) Major district Roads (MDR) Other District Roads (ODR)3. Rural
Roads & Village Roads.4. Internal Roads in Village &
Towns.
Roads density is 0.7 Km / One Sq. Km. 28.8 K.m / One Million
People.
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CHOICE OF MANDREL FORBAR BENDING
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MIX UP OF BARSELEVATIONPLANELEVATIONPLAN
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STAGGERING BARS FOR CONTINUITYIN COLUMNSNOTE:ALTERNATIVELY IF
STAGGERING IS NOT DONE, SPACING OF TIES SHALL BE REDUCED TO HALF
THE NORMAL SPACING IN THE LAPPING REGION.
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BAR LAPPING ATCOLUMN BEAM JUNCTION
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ABRUPT KINKING OF BARSIN COLUMNS
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ABRUPT KINKING OF BARSOUTSIDE THE COLUMNS
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DEFECTIVE PROVISION OFTIES IN COLUMN
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DISCONTINUITY OF BARSIN COLUMNS
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LEAVING THE BARS FORFUTURE EXPANSION
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LAPPING OF BARS INTENSION MEMBERS
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CURTAILMENT OF BARSIN BEAMS
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LAPPING / PLACEMENT OFBARS IN BEAMS
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LAPPING OF BARS INCANTILEVER BEAMS
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DEFECTIVE POSITION OFBARS IN BEAMS
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UNEQUAL COVERS IN BEAMS
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PLACEMENT OF BARS ATSLAB SUPPORT
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BAR PLACEMENT INCANTILEVERED SLAB
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MIXING UP OF BARS INTWO-WAY SLABS
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ARRANGEMENT OF BARS IN ONE-WAY SLAB
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REINFORCEMENT DETAILING IN GABLES
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REINFORCEMENT AT WALLINTERSECTIONS
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PLACEMENT OF BARS INWAIST SLAB
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REINFORCEMENT IN FOLDED STAIRCASE
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REINFORCEMENT DETAILING IN LARGE DOMES
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ONE-WAY SLABS PLACEMENT OF REINFORCEMENTSIMPLY SUPPORTED SLAB
:CONTINUOUS SLAB :CANTILEVER SLAB :
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DETAILING ASPECTS IN SLABS SPANNING IN DIFFERENT DIRECTIONS
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DETAILING ASPECTS IN SLABS SPANNING IN DIFFERENT DIRECTIONS
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CURTAILMENT OF BARS CURTAILMENT IN SLABCURTAILMENT IN CANTILEVER
BEAM
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BENDS, HOOKS AND LINKSVARIOUS FORMS OF LINKSSTANDARD BENDS AND
HOOKS
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BEAM STIRRUPSSINGLE LEGDOUBLE LEGOPEN TYPEDOUBLE LEG PARTIALLY
OPEN TYPEDOUBLE LEGCLOSED TYPEDOUBLE LEGWELDED TYPEMULTIPLE
TYPE
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ANCHORAGE FOR BEAM BARS Contd
ANCHORAGE LENGTHM 15M 20M 25TENSION50 x d45 x d40 x
dCOMPRESSION45 x d40 x d35 x d
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ANCHORAGE FOR BEAM BARS l t = ANCHORAGE LENGTHContd
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REINFORCEMENT AT BEAM TO BEAM SUPPORTHORIZONTAL LOOPSEXTRA
DIAGONAL OPEN STIRRUPS
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TYPICAL DETAILS OF BEAM INTERSECTIONS1. SECONDARY BEAM SHALLOWER
THAN MAIN BEAM2. BOTH MAIN AND SECONDARY BEAMS OF SAME DEPTH3. BOTH
MAIN AND SECONDARY BEAMS OF SAME DEPTH4. SECONDARY BEEM DEEPER THAN
MAIN BEAM
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CURTAILMENT OF BARSCURTAILMENT IN CONTINUOUS BEAM
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DIFFERENT TYPES OF TIESSINGLE TIEDOUBLE TIEDIAMOND TIE + SINGLE
LINKDOUBLE TIESSINGLE TIE + DOUBLE LINKSSINGLE TIE + DOUBLE
LINKSSINGLE TIE + DOUBLE LINKSSINGLE TIE + SINGLE LINKNOTE:1. TIE
DIA : BAR DIA
2. TIE SPACING :16 x BAR DIA
48 x TIE DIA
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DIFFERENT TYPES OF TIES
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COLUMN TRANSITIONS ts = SPACING OF COLUMN TIES
ld = DEVELOPMENT LENGTH
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DETAILING AT JUNCTIONCOLUMN TIES CONTINUED AT JUNCTIONPLANSEC.
1-1SEC. 2-2
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DETAILING AT JUNCTIONCOLUMN TIES CONTINUED AT JUNCTIONPLANSEC.
1-1SEC. 2-2
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DETAILING AT JUNCTIONBEAM STIRRUPS CONTINUED AT JUNCTIONPLANSEC.
1-1SEC. 2-2
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DETAILING AT JUNCTIONBEAM STIRRUPS CONTINUED AT JUNCTIONPLANSEC.
1-1SEC. 2-2
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DETAILING AT OPENING AND CLOSING CORNERSOPENINGCORNERPLANNOTE:
STRRIUPS & OTHER REINFORCEMENT NOT SHOWNCLOSINGCORNER
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DETAILING IN STAIRCASE
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DETAILING IN BRACKETSHORIZONTAL LOOPSINCLINED LOOPSVERTICAL
LOOPSNOTE : HORIZONTAL LOOPS PREFERRED
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TYPICAL LAP WELD IN REBAR
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TYPICAL BUTT WELD JOINT IN REBAR
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BAR KINKSBAR KINK IN COLUMNBAR KINK IN BEAM
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TYPICAL SPLICE DETAILSBONDED TYPEPRESSED TYPECOUPLER TYPE
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BUNDLING OF BARSTWIN BUNDLE(Vertical)ELL BUNDLETWIN
BUNDLE(Horizontal)TRIANGULAR BUNDLESQUARE BUNDLE
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CURTAILMENT OF BARS IN BUNDLESNOTE : ONLY BUNDLED BARS SHOWN
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TYPICAL SUPPORTS TO REINFORCEMENTMORTAR REINFORCEMENT
SUPPORTSTEEL REINFORCEMENT SUPPORTSPLASTIC REINFORCEMENT
SUPPORT
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CONSTRUCTION JOINT IN FOOTING- INDICATES DIRECTION OF
CONCRETINGPROVISION OF KICKER IS OPTIONAL
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CONSTRUCTION JOINT IN COLUMN- INDICATES DIRECTION OF
CONCRETINGContd
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CONSTRUCTION JOINT IN COLUMN- INDICATES DIRECTION OF
CONCRETINGContd
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CONSTRUCTION JOINT IN SLAB- INDICATES DIRECTION OF
CONCRETING
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CONSTRUCTION JOINT AT BEAM - COLUMN JUNCTION- PERMITTED ONLY
WHEN CONCRETING OF TAKEN UP IMMEDIATELY AFTER CONCRETING- INDICATES
DIRECTION OF CONCRETINGAB
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CONSTRUCTION JOINT AT BEAM - COLUMN JUNCTION- INDICATES
DIRECTION OF CONCRETING
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PERMITTED ONLY WHENSHEAR RESISTANCE OF CONCRETE IS
NEGLECTED.INTERFACE TREATED AS HIGH IN THE DESIGNS ANDADEQUATE
DEVELOPMENT LENGTH OF PROTRUDING REINFORCING BARS ENSURED.-
INDICATES DIRECTION OF CONCRETINGCONSTRUCTION JOINT AT BEAM -
COLUMN JUNCTION
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TYPICAL CONSTRUCTION JOINT IN ONE-WAY SLABPLANContd
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CROSS SECTION - TYPICALContdTYPICAL CONSTRUCTION JOINT IN
ONE-WAY SLAB
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TYPICAL EXPANSION JOINT(REINFORCEMENT DISCONTINUOUS AT
JOINT)25mm WIDE EXPANSION JOINTContd
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FOOTINGContdTYPICAL EXPANSION JOINTFILLED WITH SEALENT25mm WIDE
EXPANSION JOINT(REINFORCEMENT DISCONTINUOUS AT JOINT)
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R. C. HINGESTYPE - 1TYPE - 2TYPE - 3
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PILE CAPPLANSTARTER BARSTOP BARSHORIZONTAL BARSPILECLEAR
OVERHANG100 TO 150STIRRUPSSECTION 1-1BOTTOM BARS
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CIRCULAR FLOORS
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DETAILING AT SHRINKAGE STRIPS IN THIN WALLS & LARGE
SLABSPLAN TYPE 1PLAN TYPE 2
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GCPGOOD CONSTRUCTION
PRACTICEEXPERIENCEENVIRONMENTOBJECTIVEKNOWLEDGDERESOURCES
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CONSTRUCTION PROCEDURECONCEPTUAL STAGE DESIGNS & PLANS
FORMULATION STAGE ESTIMATES & AGREEMENTS
REALISATION STAGE - EXECUTIONGCP
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P.W.D. SYSTEM of Execution of WorksNECESSITYSITE
EXPLORATIONPLANS & STRUCTURAL DESIGNSESTIMATESADMINISTRATIVE
SANCTIONTECHNICAL SANCTIONTENDERAGREEMENTEXECUTION
COMPLETIONHANDING OVER
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CONTRACT
AGREEMENTPLANSPECIFICATIONQUANTITIESRATEMILESTONESPERIOD OF
COMPLETIONCONDITIONS OF CONTRACT
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MANUALSAPDSSIS CODESD-CODEPWD ACCOUNTS CODE
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L.S. AGREEMENT
PLANSPECIFICATIONSQUANTITIESRATE
TIME IS THE ESSENCE OF CONTRACT
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SPECIFICATIONDescription of item of Work Importance of drafting
Specifications
APDSSIS CODES
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WORKING WITH REINFORCED CONCRETEFORM WORKI.S. Code I.S. 456
2000
REINFORCEMENTCONCRETE
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FORMWORKI.S. Codes I.S. 3696 (Part I & II)- 1987
Efficiency of the formwork is the efficiency of the concrete
structure
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Scaffolding & ShutteringSCAFFOLDINGVertical support system
SHUTTERINGForm rendering systemFORM WORK CONSISTS OF SCAFFOLDING
& SHUTTERING
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Conventional Wooden BalliesSCAFFOLDING with CASHEWRINA TREE
STEMS used as props
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Mild Steel Props with JackSCAFFOLDING with MILD STEEL JACKSused
as props
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Mild Steel Frame SupportsSCAFFOLDING with MILD STEEL FRAMES Prop
support system
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DOKA FRAMESDoka Frame work system with HD Towers
Each HD Tower with Four vertical props and cross bracings
designed to carry 25 Tons vertical Loads
SHUTTERING
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Types of shutteringWooden PlanksMild Steel PlatesPlywood
Sheets
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Plywood shuttering
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Shuttering supports
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Dome ShutteringWORKING WITH RCC
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REINFORCEMENTMATERIAL STANDARDSConformance with relevant IS
CodesEx: I.S. 1786 1985 - High Yield Strength Deformed (HYSD) Bars
of Fe 415 GradeTESTING for 0.2% PROOFSTRESS, ELONGATION, TENSILE
STRENGTH, BEND & REBEND WORKMANSHIPConformance with relevant IS
Codes and PracticeEx: SP 34 for Concrete Reinforcement and
Detailing
-
BAR BENDING DETAILINGBAR BENDING SCHEDULESCOVERDEVELOPMENT
LENGTH COMPRESSION & TENSIONANCHORING BARS BENDS & HOOKSLAP
SPLICNG COMPRESSION & TENSIONCURTAILMENTSPACING OF
REINFORCEMENTBUNDLING OF BARSPLACING & TYING
WORKING WITH RCC
-
Nominal COVER BAR BENDING DETAIL
EXPOSURENOMINAL CONCRETE COVER in mm not less thanMild
20Moderate 30Severe 45Very severe50Extreme75
-
DEVELOPMENT LENGTHTypical Reinforcement details of Mat, Column
BarsDevelopment Criteria for column bars in footing
BAR BENDING DETAIL
-
Development LENGTH in stirrupsReinforcement details of STIRRUP
hooks
BAR BENDING DETAIL
-
ANCHORING BARSReinforcement details of Beam Bars
Anchoring the top of bar of the BeamsBAR BENDING DETAIL
-
CURTAILMENTCurtailment of Reinforcement in Beam
BAR BENDING DETAIL
-
LAP SPLICINGSplicing of Reinforcement
BAR BENDING DETAIL
-
PLACING & TYINGSpacing & Placing of Reinforcement
BAR BENDING DETAIL
-
SPACERSUsage of Spacers in Reinforcement
BAR BENDING DETAIL
-
CONCRETEMATERIAL STANDARDSConformance with relevant IS
CodesWORKMANSHIPConformance with relevant IS Codes and Practice
-
CONCRETE MATERIALS CEMENTCOARSE AGGREGATEFINE
AGGREGATEWATERADMIXTURES
-
CEMENT33/ 43/ 53 GRADE O.P.C.RAPID HARDENING PORTLANDPORTLAND
SLAGPORTLAND POZZOLANA
-
COARSE AGGREGATE Conformance with IS 383Size and
GradationFlakiness IndexAggregate Impact valueWater Absorption
FINE AGGREGATE
-
COARSE AGGREGATE GRADATIONIS 2386 Part IIS 383 - 1970Particles
retained on 4.75 mm IS SieveSieve Analysis for Single sized &
Graded
COARSE AGGREGATE
-
FLAKINESS INDEXCOARSE AGGREGATEIS 2386 Part I% by weight of
Particles whose least dimension is less than 3/5th of their mean
dimension. Flakiness Metal Gauge
-
AGGREGATE IMPACT VALUEIS 2386 Part IVRelative Measure of the
resistance of an aggregate to sudden shock or impact.
(Weight of fraction passing 2.36 mm IS sieve/ weight of sample)
* 100
COARSE AGGREGATE
-
FINE AGGREGATEConformance with IS 383GradationBulking Fineness
ModulusClay Content
WATER
-
FINE AGGREGATE GRADATIONIS 2386 Part IIS 383 - 1970FINE
AGGREGATE: Particles passing through 4.75 mm IS Sieve and retained
on 150 microns IS SieveSILT: Particles passing through 150 microns
IS Sieve and retained on 75 microns IS SieveCLAY: Particles less
than 75 microns
FINE AGGREGATE
-
BULKINGFINE AGGREGATEDampness causes increase in the volume of
Sand known as BULKINGIS 2386 Part III
-
FINENESS MODULUSIS 2386 Part I
FINENESS MODULUS: Numerical index of sum of percentage of
weight/ volume of particles retained from 40 mm to 150 micron IS
Sieve and divided by 100
FINE AGGREGATE
-
WATERPotable water Conformance with IS Code IS 3025 (Part 22
& 23)
-
PROPERTIES of CONCRETEGrades of CONCRETEWorkability -
SlumpMinimum/ Maximum Cement content Water/Cement RatioDesign Mix/
Nominal MixProduction, Compaction, Placing & CuringSampling
& Acceptance Criteria
PROBLEMS
-
Grades of ConcretePROPERTIES
Group Grade DesignationCharacteristic Compressive
strengthORDINARY CONCRETEM 1010 N/ mm2M 1515 N/ mm2M 2O20 N/
mm2
STANDARD COCNRETE M 2525 N/ mm2M 3030 N/ mm2 M 3535 N/ mm2M 4040
N/ mm2M 4545 N/ mm2M 5050 N/ mm2M 5555 N/ mm2
HIGH STRENGTH CONCRETEM 6060 N/ mm2M 6565 N/ mm2M 7070 N/ mm2M
7575 N/ mm2M 8080 N/ mm2
-
Slump of ConcretePROPERTIES
DEGREE OF WORKABILITYSLUMP IN mmVery lowDetermination of
Compaction factorLow 25 75Medium 50 10075 100 High100 150 Very high
Determination of flow
-
Minimum Cement ContentPROPERTIES
ExposureGrade of Reinforced ConcreteMinimum Cement ContentWater/
Cement RatioMild M 20300 Kg/m30.55Moderate M 25 300
Kg/m30.50SevereM 30320 Kg/m30.45Very severeM 35340 Kg/m30.45Extreme
M 40360 Kg/m30.40
-
Maximum Cement ContentCement content in excess of 450 Kg/m3
should not be used unless specially designedPROPERTIES
-
SAMPLING Three test specimens shall make one sample for testing
at 28 days. Test results shall be average of three
Specimens.Individual variation shall not be more than +15 % of the
average.PROPERTIES
Quantity of Concrete in work in m3Number of samples1 5 16 15 216
30331 50 450 and above4 + one additional sample for each additional
50 m3 concrete
-
Target StrengthMean of 4 consecutive test results Characteristic
compressive strength + 0.825 * Standard deviationFor M 15 = fck + 3
N/mm2For M 20 and above= fck + 4 N/mm2Target strength or Mean
strength = Characteristic compressive strength + 1.65 * Standard
deviationft = fck + 1.65 x Acceptance criteria
-
Flexural StrengthMean of 4 consecutive test results
Characteristic compressive strength + 0.3 N/mm2Individual Test
result Characteristic compressive strength - 0.3 N/mm2
PROPERTIESFlexural strength, fcr = 0.7 fck N/mm2Acceptance
criteria
-
SOME COMMON PROBLEMSUSAGE OF NON-SPECIFIED MATERIALSFRAGILE
SCAFFOLDINGFORMWORK DISTORTIONIMPROPER MIXINGDISTURBED
REINFORCEMENTIMPROPER COMPACTIONCONSTRUCTION JOINTSINSUFFICIENT
CURING
-
CONSTRUCTION JOINTSCONSTRUCTION JOINTS shall be discouraged
unless essential
CONSTRUCTION JOINTS Should comply with IS - 11817
-
DESIGNSTANDARD DESIGN PRACTICEPRACTICAL ORIENTATIONARCHITECTURAL
DESIGNSTRUCTURAL DESIGN
-
CONSTRUCTION TECHNOLOGYRCC Frame Structures :Generally buildings
are constructed in two categories.Framed Structure usually built
with column and beam and in filled brick walls.Load bearing
structure is usually built with 1 brick thick both for external and
internal walls.The Design of a structure presents two told problems
:If has to be so constructed that it serves the need efficiently
for which it was intended (Functional design)It has to be strong
enough to resist the loads and forces to which it is subjected
during its service (Structure design)
-
The important aspects in the structural design are To determine
the loads / forces which the frame work will be required to
support.Selection of a suitable structural arrangement and
materials of construction.Analyzing the internal stresses in the
frame work. Proportioning the members of the frame work.General
Design Consideration :1. Aim Design : To provide a safe and
economic structure complying to the users requirement.2. Method of
Design :Structure and structural elements shall normally be
designed by limit state method.
-
Mix design with suitable materials, quality control, adequate
detailing and good super vision are equally important. 3.
Durability, Workmanship and Materials :Quality of concrete, steel,
other materials, workmanship, should be adequate for safety,
serviceability and durability.Type of construction Load bearing (up
to 1 or 2 floor)Reinforced frame (RCC)Composite construction For
High rise structuresSteel framed constructionConcrete walls (shear
walls) structures.
-
Code of good practice for low rise simple load bearing masonry
structures.
In order to counter horizontal acceleration of earthquake ties
have to be introduced at sill, lintel and roof level.Roofs of such
masonry buildings shall be kept as light as possible.Roofing of
such buildings shall be designed and constructed as single
diaphragmIn Earthquake prone areas 50% of the walls shall be
designed as shear walls minimizing openings.
-
Framed Structures :In the case of framed structures the members
of the structural system shall be designed so as to form a unitary
moment resisting frame to counter earthquake load and to suitably
accommodate deflections.In the case of stilt floor with free
standing columns which do not have any other structural members
such as shear walls etc., they shall be designed according to loads
and moments.The structural system should be simple and shall have
symmetry as far as possible with the following .Design of corner
members of the building to resist the concentration of seismic
forces.The joints between various structural members shall be
suitably strengthened.The structure shall offer balanced
resistance. This should be achieved by keeping the center of
resistance close to the center of mass of the building as far as
possible.
-
In the case of unsymmetry where the centers do not coincide, the
members shall be suitably designed for the torsion generated by
earthquake forces.In the case of certain class of buildings having
higher safety requirement suitable measures like the frames shall
be suitably braced on the periphery and shear wall shall be
introduced.Symmetry of the structural system may be maintained as
far as possible even in the case of buildings where geometric
symmetry is not there. All non structural members like plumbing,
false ceiling, air conditioning ducts etc of the building shall be
suitably anchored in the position so as to resist earthquake
forces.Structural glazing / curtain wall shall be designed and
constructed on the faade of the building so as to accommodate
deflection in the structural members safely. Suitable glass like
tempered glass laminated glass shall only be used in the panels.In
the case of piped gas supply, the pipes shall be embedded and
passed through walls with adequate sleeves to avoid any
ruptures.External cladding on the walls with heavy material like
granite, marble etc shall be suitably anchored with pins etc and
their load shall be accommodated for.
-
Sub Soil Exploration and SamplingAdequate knowledge of the sub
soil characteristics for safe and efficient design of
foundation.The basic aim of a sub soil exploration is to obtain the
strata grapy and physical properties of the soils underlying the
site. Location of ground water level.
-
Methods of Tests :Open Test : Suitable for shallow depth.Boring
: Suitable for deep exploration (like tube, Augur borings) Sub
surface sounding.Geophysical Methods.The samples collected should
represent the nature of subsoil.S.B.C. of soils shall be arrived
based on shear parameters as per the relevant IS Code 6403
1981.Also necessary to conduct standard penetration test (or) plate
bearing test to assess the safe pressure with regard to
settlement.3)The settlement aspect is to be examined carefully in
the case of clayey soils.
-
Foundations :Depth of foundation is to be decided based on the
soil strata from the trial pits / explorations conducted.Foundation
are normally placed below the ground surface.The purpose of
providing a foundation is to distribute the load over a layer area
at a uniform rate so that the pressure does not exceed the
allowable bearing capacity of soil below :
-
Objects of Foundations :Foundations are provided for the
following purposes.To distribute the total load coming on the
structure on a large area so as to bring down the intensity of load
at its base below the safe bearing capacity of the sub soil.To
support the structure.To give enough lateral stability to the
structures against wind, rain, earthquake, etc.To prepare a level
and hard surface for concreting and masonry work.
-
V.To transmit the superimposed loads through side friction and
end bearing in case of deep foundation ViTo distribute the
non-uniform load of the superstructure evenly to the sub-soil.ViiTo
provide structural safety against undermining or scouring due to
animals, flood water etc.,ViiiTo prevent or minimize cracks due to
movement of moisture in case of weak or poor soils.
-
Foundation :
Engineers need to know the character and magnitude of forces in
order to design and contact structures.One has to study the system
of soil below the earth surface at various levels under ground
depending upon the past experience.Repairs to foundations are
expensive. Structures should be founded an stable soils.Certain
soil deposits wherein wetting of the soil beyond a stress level
causes steep reduction in stiffness resulting from disruption of
soil structure.
-
Subject to rate of loading, disruption in soil structure takes
place at a faster pace than the development of new structural bonds
which Leeds to vertical deformation at locations of high stress due
to disturbance of soil structures.Problems associated with
foundation in clay soils are well known. 7.Swelling clays create
large uplift forces on the peripheral walls during rainy season. A
reverse situation may arise at region of moderate rainfall when the
central region of a building founded on clay soil is prone to
swelling during dry spells.
-
Differential settlement due to unconsolidated fill.
Differential settlement due to uplift of shrinkage soil, shrink
and expand with changes in moisture content.Vertical and diagonal
cracker are noticed on external walls.8.The problem of dampness in
buildings requires a systematic approach to determine the causes of
leakage, the source from which the moisture is derived and measured
which are likely to prove effect ion.
-
TYPES OF FOUNDATIONS
-
Settlement of Structures :Principal causes of occurrence of
cracks :Moisture changesThermal variations Elastic deformation
CreepChemical reactionsFoundation movement and settlement of
soilVegetation
-
B. Principal causes of settlement : To design the foundation to
minimum settlement and as uniform as possible.
C. By Static Loads1. Elastic deformation. 2. Plastic flow.3.
Consolidation of saturated clay beds.
-
b) By Dynamic Loads :Settlement from this cause can occur in all
kinds of soilsSettlements are due to action of stress waves from
inertia forces.
c)By Lowering ground water.
1.In some cases, the settlements due to this cause are brought
about by changes in the stress conditions in underlying soil. 2.In
other cases the lowering of the ground water table brings about
settlement due to soil shrinkage.
-
Composite Construction :A composite column consists of steel or
cast Iron care with reinforcement placed around it and put together
in concrete.Maximum area of core must be limited to 20% of gross
area of the construction.Minimum of 75 mm clearances between core
and helical reinforcement (or) 50 mm clearance between core and
ties to be maintained.Composite columns are normally provided in
case of long loads and where the size restriction is severe. IS 456
has the recommendations :The allowable axial load P on a Composite
column consisting of structural steel or a cast Iron column
increase in concrete with both longitudinal and spiral
reinforcement.
-
Introduction :Over the last five years there has been a massive
world wide tall building construction boom.Many innovations in
design and construction and the tallest building in the world has
became 50% taller than previous record.Man is a gregarious being It
has always been a human aspiration to create taller and taller
structure.Improvements in concrete mixes have made high rise
construction more attractive, pre-cast concrete member are also
used.HIGH RISE STRUCTURES
-
Several technological advances occurred in the late 19th century
that combined to make sky scraper design and construction
possible.
Mainly ability to mass produce steel , the safe and efficient
elevators, development of improved techniques, for measuring and
analyzing structural loads and stress.The following recommendations
may be treated as code of god practice as regards seismic design of
the structural system of the building.
-
1. PRESTRESSED CONCRETE a.Prestressing is a technique of
introducing forces in a structural member so as to produce
stresses.b.Generally the force is applied by means of high tensile
bars, which are stretched and anchored by suitable
means.c.Prestressed concrete members have many advantages over
members of reinforced concrete. In RCC, the concrete in tension
zone is inactive, in prestressed the whole section can be arranged
too be in active compression. Tensile cracks can be completely
eliminated in prestressed concrete and more durable also the effect
of dead loads and shear forces can be reduced by proper
prestressing. d.The principal materials used in prestressed
concrete work are high tensile steel and high strength
concrete.INNOVATIVE DESIGNS
-
e.Pre tensioning - A method of prestressing concrete in which
prestressing steel is tensioned before the concrete is
placed.f.Post Tensioning : - A method of prestressing concrete in
which prestress steel is tensioned against the hardened concrete.g.
The prestressing steel should conform to IS 1785 and IS 2090 duly
testing for ultimate tensile strength and proof stress.h.Post
tensioned works are generally grouted to protect the steel from
corrosion. The grout is injected after washing the hole with water
under pressure, by means of grout pump. Pressure of 3.5 to 7.5
Kg/sq km are used at in practice.i.The permissible stresses are
based on IS 1343 code of practice for prestressed concrete duly
adopting prestressing procedure.
-
2.Post Tensioned Slab.a. In this case, the pre stressing steel
is stressed after the concrete is cast. In practical buildings,
constructions, post tensioned slab systems are used.b. Post
tensioned system can be either bonded or un bonded. The choice of
bonded or un bonded post tensioning system involves the technical
characteristics and differences inherent in each type of tendon and
the economics related to those differences. The important technical
considerations are strength and corrosion protection.
-
c.The main advantages of P.T. slabs over conventional R.C. in
situ floors are due to increased clear spans thinner slabs, lighter
structures, reduced cracking reduced storage height, rapid
construction etc.
-
2Tall concrete Apartment Buildings and composite office
Buildings.Tall residential towers have given rise to the need for
new structural systems. Many tall office towers around the world
use composite steel/concrete system.Structural Systems.The
advantages of concrete of lower cost, speed of construction, ease
of finishing, fire proof characteristics and structural stiffness
are well known.
-
d. Composite structural system.Using both steel and concrete for
columns.Steel structure could be built at its normal speed
.Concrete encasement of the exterior column provided structural
rigidity and fire proofing.Composite structure was economical 75
storey; 300 meters tall chase plaza in Houston (N.A.)Steel has the
beneficial material property like durability, flexibility and high
strength to weight ratio.Steel is reusable, recyclable and consumes
less energy.
-
High Rise Building Boom in INDIA.
Wind Engineering is emerging in India ever since the need for
taller and slender buildings came into picture.Wind Loads on the
structural frames are required for the design of beams; columns
lateral bracing and foundations.
-
Earth Quake :Earth Quake loads are another type of lateral load
which is considered for design as well.However, considering the
rare chance of simul tanuous occurrence of both earth quake and
high wind, both wont be combined together in any structural
design.
Conclusion :
Construction of high rise buildings involves a number of
disciplines besides civil Engg. Structural engineering, Plumbing,
fire protection etc., close and continuous coordination between all
the concerned.
-
Advanced Construction Techniquesin High rise structures.Seismic
Design :1.Seismic design and their application in construction
practice have contributed a positive sense of confidence with which
to face the problem. 2.A structure is designed to resist the
vertical acceleration 1g by virtue of its weight only.
-
3. As such most of the seismic designs take into consideration
only the Horizontal component of ground acceleration due to an
earth quake.4.Codes use the lateral stress formula for arriving
addl. Stresses, that are likely to disturbs the structure during a
shock.5. Magnitude of lateral stresses would be a function of a
number of factors.
-
a.The ground acceleration due to an expected shock during the
design life of the project. b.The weight of the structure. c.Type
of construction.6. During an Earth quake, when the ground tends to
move in one direction, the lateral force exerts a shearing effect
on the building above and hence referred as base shear
-
Base Shear face = F = a/g W
Where a = (ground acceleration) Values (0.15&0.02)
g = acceleration due to gravity
w = Weight of the structure.
-
General guidelines to minimize the risk of building. Foundation
:Structures built on loose soil/weak rocks will hare to withstand
grater risk compared to founded on solid bed rock.This is due to
that soil particles undergo a lot of compaction during seismic
shocks there by causing settlement.
-
2. Foundation should be excavated to same level as far as
possible of continuous type.
3.Super structure should be thoroughly tied up with the
foundation by introducing keys/or reinforcement to offer max.
resistance against sliding at that level.
-
Roof : 1.Minimize the lateral shapes.2.Projection beyond the
roof level should be altogether avoided or kept minimum. General
:1.All the parts of same building the foundation superstructure and
the roof, should be firmly find together so that entire structure
act as a unit during a shock.
-
2.Uniform height should be given to structure. Architectural
fancies like parapets, cantilevers, arches and domes etc., should
be avoided. Behavior of concrete structures :Ability of the
structure to sustain large deformation.Rigid structure attracts
higher loads than a flexible structure under seismic
condition.Concrete being brittle is in capable of sustaining large
deformation without correctly detailed steel reinforcements
-
4. Basic principle of earth quake resistant design in to ensure
ductility (ability to deform without rupture) of structure to
absorb large deformation without damage.Ductility of concrete
structures can be ensured by proper detailing the reinforcement as
per the relevant cods, IS 4326 1993 and 13920.Structure should be
constructed to the standard specification.Trained persons to be
preferred for construction.
-
Strong column and weak beam conceptsWhen a structure a subjected
to Lateral roads as in case of wind or earth quake forces its
behavior is governed not only by strength of beam & column, but
also by capacity of beam column joints to sustain large lateral
deformation.
-
Foundation :Shallow footings weaken their seismic resistance.Un
even settlement of footings due to ground movement, especially at
shallow depth, may lead to premature structural failure.Multi
storages structure with cellars (Under Ground) may survive Earth
quake better than those on shallow isolated footings.Best way of
building earth quake resistant structure is proper supervising at
every stage of planning, design and construction.
-
1.Foundation (Isolated footing, Rafts)2. Detailing (Beam column
Joints, Stress Reversal, ductility)3. Planning (Floating and
staggered column, location of lift walls & Cellar)4.
Restrictions on structural Heights.5. Spaces around structures to
avoid sequential collapses.6. Building MaterialsCertain Aspects to
be appraised for construction practices.
-
7. Stilt floors 8. Water Tanks on roof top.9. Masonry structures
(Load bearing walls / infield)Structural System under lateral Loads
for high rise structures.Lateral Loads 1. Wind Loads2. Earth Quake
Loading.
-
2. Serviceability :Lateral deflection of structure is lateral
drift. Which is the relative magnitude of lateral displacement at
the top of building with respect to the height.Relative Vertical
defection :In tall buildings relative vertical movement between
exterior and interior columns or between column and shear or core
walls which may occur due to a.Thermal expansion/contraction of
exterior columns
-
b.Different axial load stresses in column and shear cores
leading to creep deformation of members. c. Differential settlement
of foundation for shear core and adjacent column.Structural Systems
Frame Buildings.Shear Wall buildingsStaggered wall Beam System
-
4. Shear wall acting with frames.5. Single framed tube.6. Tube
in tube.
Frame In a framed type structure the lateral displacements
(Drift) may be true parts.Due to Bending in the column and
beams.Due to axial deformation of columns.
-
Shear WallsShear walls are plane elements made up of reinforced
concrete thin walls having length and thickness providing lateral
stiffness.Concrete shear walls may be cast in situ or
pre-cast.pre-cast panel walls are also used within a concrete or
steel frame to provide lateral resistances.The ductile shear walls
used in Earth quake resistant design have to be detailed
carefully.Coupling beams should have diagonal reinforcement to
develop shear resistance.
-
To design shear walls for the lateral load resistance and also
satisfy the ductility demand during cyclic loading.
-
Behavior of Low Rise Shear Wall.
Since the Bending moments are not large the steel may be evenly
distributed across the length with marginal increase near the
edges, to such walls the steel requirement for flexure may be
satisfied by providing the minimum steel moreover, in such walls
the elastic deformation can be made to absorb major portion of
seismic energy.
-
Shear Walls with Openings
Windows, doors and service ducts require openings to be provided
in shear walls. Irrational shear walls warrant finite element
studies for evaluating internal forces. An example of irrational
shear wall is shown in Fig (a). The staggered arrangement of
openings may seriously limit the shear transfer between the
openings Fig (b) shows a shear wall supported on sloping legs. Such
irregularity may lead to deflection opposite to the direction of
motion. Such structures -------- disaster.
-
Coupled Shear WallsMany shear walls contain one or more rows of
openings. Examples are shear cores, lift wells, stair wells etc.
The walls are connected by beams which are short and deep. An
realized shear wall structure and its deformations due to lateral
loading is shown.
-
The overturning moment Mo, is resisted by a moment induced in
wall1 A moment induced in wall 2 and Equal and opposite axial
forces T generated in both walls (One in compression and the other
in tension). The corresponding equilibrium equation is
-
Over view of Foundation for TALL Buildings.A structural Engineer
has a variety of choices for the material to build on top;The
geotechnical engineer has to deal with the material that lies below
the structure.Generally structures built on soft ground soil
suffered damage many times more than similar structures on hard
rocky foundation. Structures standing on alluvial soil received
greater shaking due to lower elastic modulus of soil than rock.
Also structures standing on soft soil has dynamic interaction with
soil.It is a fact that short buildings on rock, tall buildings on
deep alluvial soil may exhibit a very large amplification of the
ground motion in the structure causing its damage or even
collapse.
-
Types of Foundation.Choice for the type of foundation to be
adopted depends on both the structure and the ground.
Choice of Foundation Type
-
TYPES OF RAFT FOUNDATIONS
-
Raft verses pile raftProvision of deep foundation is no guaranty
for tall structures founded in seismic areas.The soil beneath may
get liquefied resulting in lateral instability by shearing of the
piles in the liquefied zone or by overhearing at the pile cap
structure interface.
-
Pre-Cast ConstructionWide spread utilization of new materials,
construction methods and equipment.Flat slab / Hallow concrete core
slab construction enhanced the speed and economy.Modern elevators
with latest facility.Panel to panel connection of framing members
shall be ensured so as to enable the structure to resist earthquake
load as a single unit.Suitable jointing procedure and workmanship
shall be adopted between various interlocking prefab panels to
avoid weak connections.Suitable anchoring systems like dowel bars,
hooks etc shall be used to prevent dislocation of panels under the
action of seismic loads in the quake prone areas.
-
Isolation of the structure from its foundation may be achieved
by using suitable rubber bearings so as to cut transmission of
seismic forces to the structure from the ground. This method shall
be employed for buildings of 3 to 15 storeyes to dampen earthquake
loads. In such systems the frames shall be suitable braced.
-
Structural SystemsSteel is now giving way to composite steel
concrete mega column.The mass and the rigidity of concrete provides
twice the dampening effects compared to steel, reducing forces due
to wind and the cost of construction.Improvement in concrete mixes
have made high rise construction more attractive.Self compacting
concrete is increasingly used.Structural concrete has better
resistances to fire.Flat Slab construction reduces the distance
between floors, increase the number of floors for a particular
height.Modern forming system greatly increase construction
productivity.Advances in concrete pumping, self climbing placer
booms help in fast delivery of concrete.
-
Pre-cast concrete The use of pre-cast concrete results in
significant cost savings along with speed of construction,
durability, versatility and ease of maintenance.Comparative Costs
In situ and Pre-cast
-
Pre-cast hollow core slabs
Reinforced / Prestressed Hallow core slabs are the most widely
use pre-cast flooring in the develop world.Manufactured in a
factory by long line slip-forming.The depth of hollow core slabs
range between 150 mm to 500mm, used for spans ranging from 3mm to
20 meters.
-
They are primarily used as a floor or roof deck systems,
economical and efficient. The top surface can be prepared for the
required floor finish.The under side can be used as a finished
ceiling as installed, by painting or by applying acoustical
spray.For a given loading and fire endurance rating, span length
and slab thickness may be optimized.Span-depth ratio of 45 is
common for floor & 4 roofs. Hollow cores are also used as air
heating ducts or for air conditioning system.Hollow core slabs have
been used in the advanced countries.Hollow core units have been
used in only one project in India IT Park building at Bangalore.
Where the units are prefabricated at the site
-
The weight of the Hollow core slabs is reduced as compared to
solid slabs, reducing size of columns and foundation, making more
economical.
-
Double Tee Sections :
-
Pre-cast double tee Sections are used for simply supported spans
up to 25mtrs as floor / roof element.The slabs consisting of this
section are manufactured in steel moulds with high degree of
dimensional stability and surface finish.Double tees are also used
as wall panels.These are extensively used in the U.S for parking
garages.Pre-cast concrete panel 50mm thick with integrated
structural reinforcement and special lattice girders are used as
permanent formwork. Double pre-cast concrete panels for walls.After
erection of Pre cast plank , slab top reinforcement is placed and
concreted in situ. Plank and the in situ concrete jointly act as
monolithic slab.
-
Pre-cast stair cases :Pre-cast stair cases are viable for high
rise buildings.Fixing may be in corporate but may also be drilled
and fixed on site.Typically, the two halves of the concrete stair
are jointed with a proprietary high strength mortar material in
corpora ting a large percentage of steel fibers . The monolith unit
formed with the in-situ joint has no inter mediate support between
floor levels, results in very elegant method of constructions.
-
Pre-CastConstruction with pre-cast Joists and filler blocks
should confirm to IS 6061 Part I and II.Cast is situ construction
as per IS 456 1978 in composite construction with steel Joists,
R.C. slabs and shear connectors.Ribbed slabs spanning in two
directions at right angler may also be treated as solid slabs
provided that spacing of Ribs is not more than 12 times Flange
thickness.Size and Position of Ribs.In situ ribs should not be less
than 6.5cm wide. Spacing at centre not greater than 1.5 meters
apart, depth excluding topping should not be more than four times
their width.Hollow Blocks :Can be of any suitable material as per
IS code 3951-1975.
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High Performance Concrete (HPC)Strength of concrete 40 MP a to
85 MP aAdvantages :Long term economy, durability and service
life.Low maintenance and repair cost.Small cross section, reduction
in number, size of element.Reduced formwork area, cost.Reduced
cover to reinforcement.Slender members, ease in construction and
transport.HPC is denser than that of a standard concrete thus
increasing the corrosion resistance and durability.
-
Mix Proportioning for HPC :Optimum cement and admixture
quantities involving more trial batches.Admixture cement
compatibility to be scrutinized for high strength and
durability.Water cement Ratio is usually limited to 0.35.Cement
quantity ranging 300 to 400 kg / cumHPC must be cured as soon as
possible on initial setting of concrete.
-
Self Compacting Concrete (SCC)Self Compacting concrete is a mix
that can be compacted into every corner of a formwork, purely by
means of its own weight and without vibration.SCC is produced from
normal concreting materials and complies with the strength grades
in the Code.The mix may incorporate steel and/or polypropylene
fibers. Coarse aggregate may be up to 40 mm. Sand can be finer than
normal as the material less than 150 microns may help increase
cohesion, thereby resisting segregation.
-
5. Cement and fillers (GGBS of Fly ash) are required for
cohesion and stability in larger proportions.6.Super plasticizers
are essential to ensure flow characteristics and workability
retention.7.Properties of SCC (flowability, workability etc) are
determined by special test methods.8.SCC can be effectively used in
heavily reinforced elements, underwater structures etc.9.SCC is now
being used in many high rise buildings particularly for the
components with high density reinforcement such as raft foundations
columns etc.,
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PRE FAB STRUCTURESIntroduction :Prefabricated construction being
a new technique some of the essential requirement of prefabricated
components and elements are discussed.Since the aim of
prefabrication is to effect economy improvement in quality and
speed in construction, the selection of proper materials for
prefabrication is an important factor. Prefab structures like
Project House, Farm Tanks, Resorts, School Buildings, Store Shed,
Industrial Shed, Ware Houses, and many more are under construction
using prefab system.
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Prefab shelters are constructed in track and panel system with
advantages of simplicity in construction.Requires very light
foundation.Durable, comfortable and affordable.Light weight, High
strength, Earth quake safe.Easy to transport; easy to eruct.Can be
dismantled and reassembled at any other location.Basic Materials
used for the wall panels and roof are 10, 12, and 16 mm panel
(Cement Bonded partial board)The particle boards are weather fire
and termite resistant. Best suited for exterior application due to
their strength and durability.Assembly of panel walls and the roofs
are done with cold roll formed anticorrosive G.I. profiles
specially designed to give adequate strength to the structures.
-
Design Criteria :Structure with wind condition of 55m/sec,
seismic zone V and temperature 0 to 500 C.Material of double skin
insulated wall panels and single skin insulated false
ceiling.Corrugated GI sheets have a minimum galvanizing loading of
220gsmAll other GI profiles shall have minimum galvanizing of 120
gsm conforming. IS 277 2003.Wall shall be made in sandwich panel
system using 2 nos. 10 mm thick cement Flat sheets / boards
(As-best-as free) conforming to IS 14276 1995 & 14862.Roof
shall be with galvanized corrugated sheet of 0.63mm thick
conforming to IS 277 2003, having minimum 220gsm galvanizing laid
over a frame work of trusses, columns, and purlins (rectangular
Hallow steel section) fixed using suitable fasteners like J
hooks.
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Trusses made of Rectangular Hollow section 66 x 33 x 2.9
mmTrusses supported on column using section 96 x 48 x 3.2 mm
conforming to IS 4923 1977.Purlins made of sections 66 x 33 x 2.9
mmDoors :Frame shall be made from pressed steel fore sided frame
using CR steel of size 75 x 45 x 1.5 mm thick conforming to IS 513
1994.Shutter made out of 32 mm thick flush door as for IS 2202 1999
and steel rectangular hallow box profile of 1.25 mm thick as per IS
Windows and VentilatorsShall be made from pressed steel using CR
Steel of 1.5 mm thickness of size 75 x 45 mm profile conforming to
IS 513 1004.
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Partial Prefab & Cast in situ R.C Walls Structures Where RC
Walls are intended to carry vertical loads, they should be
generally designed in accordance with columns.The minimum thickness
of wall should not be less than 100mm.The load carrying capacity of
the walls should be calculated as for columns.When the effective
height of wall exceeds 12 times wall thickness slenderness effects
should be considered as in columns.The minimum ratio of vertical
reinforcement to gross concrete area should be 0.0012 for Hysd
bars
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Spacing should be three times walls thickness nor 450 mm for
both vertical and horizontal.Minimum ratio of Horizontal
reinforcement to gross concreted area should be 0.0020 for Hysd
bass. Buildings shall be designed and constructed to resist the
effects of design lateral forces.The design lateral force shall be
disturbed to the various floor levels.The design base shear VB as
computed shall be distributed along the height of the building
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SCS SYSTEMThe Evolution of Building Technology Unique
pre-engineered custom-made lost-in-place formwork system consisting
of Modular Wall Formwork Panels.Components of SCS SystemFiber
Cement BoardLight Gauge Galvanized Steel StudsReinforced
ConcreteExpanded Polystyrene
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Target market segments advantages for specific applications
ApartmentsVillasHotelsCommercial BuildingsMalls High rise
buildingAPPLICATIONS
-
USPWhat are our USPs..?PROVEN SYSTEM : Tried and tested,
established in several countries SPEED : Walls erected in at least
1/3 rd less the time compared to conventional constructionQUALITY :
Plumb, line and level, proper edges, no cracks or defectsDURABILITY
: Earthquake resistantNO BRICKWORK : No worry about brickwork
quality, soaking in water, mortar, shortage of good masonsNO
PLASTERING : No messy mixing at site, workmanship issues, curing,
repairing cracksTECHNICAL SUPPORT : Full back-up engineering and
structural design support
-
A proven system Tried & Tested in several countries
-
PRECAST SLABS
-
Elevation features incorporated during panel manufacturing
-
SCS MODULAR Systems Cost Effective, Relocatable, Flat-Pack
System
-
Manufacturing Facility in India
-
Advantages & Benefits:
Speedier Design Execution phase in project execution
Elimination of tedious, time-consuming manpower intensive
processes
High quality James Hardie fibre cement boards guarantee long
life of the structure
Faster return on capital invested
Lower dependency on unorganized labor & increased
reliability on completion schedules
Reduced maintenance / repairs
-
Advantages & Benefits:
4.Inlaid plumbing & electrical lines, superior quality
finish surface eliminates plastering
5.Bill of quantities defined before start of work
6.Thinner walls but as strong as those made from conventional
methods
Faster availability of super structure for finishing & other
value addition works
Better predictability of costs & hence better control
Increased floor area
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CONCRETE MIX DESIGN
(A) CRITERIA
1.Concrete Mix design relevant IS code 10262 1982.2.Rational
proportioning of the ingredients of concrete is the essence of
concrete mix design shall be as follows Design Mix concrete -- By
designing the concrete mix . Nominal mix concrete -- By adopting
nominal concrete mix. Design Mix concrete is preferred to nominal
Mix.3.The purpose of concrete mix design is to ensure the most
optimum proportions of the constituent materials to meet the
requirements of the structure in terms of workability durability
and strength and knowing the source and properties of aggregates
and type of cement to be used.4.The age old method of specifying
concrete by volume is being rapidly replaced by specifying concrete
in terms of grades ie. M15 ,M20 etc.5.Needless to say , a properly
designed concrete mix for the specified strength requirements
should have the minimum cement content to make the mix
economical.
-
(B) Principles of Mix Design Design Requirements :
(1) Grade of concrete -- The grade M15,M20 indicates
characteristic strength , fck of 15 N/mm2 , 20N/mm2 respectively,
and standard deviation based on degree of control to be exercised
on site. (2) Type of Cement such-- The grade of Ordinary Portland
cement (OPC) such as 33,43, 53 grade .PPC ,PSC to relevant IS
specification.(3) Type and size of -- Natural sand , crushed stone
,confirming to IS 383. Aggregates (4) Nominal Mixing -- 40mm/
20mm/10mm as per IS 383.
(5) Max /Minimum -- Required for durability consideration ,kg/m3
. cement content
(6) Type of Mixing and -- Fresh potable water , ground water to
be used. Curing Water
-
(7) Max Free water cement - Required for consideration of
strength and /
(8)Ratio by weight -durability for different exposures , and to
meet the requirement.
(9) Degree of workability -This is dependent on placing and
compacting Of concrete conditions.
(10) Air content - By the use of suitable air entering
admixtures durability can be enhanced. Generally 4 to 5 % based on
Max size of aggregate.(11) Type of admixture used.
(12) Maximum /minimum Density of concrete. Max /Min temperature
of fresh concrete.
-
(C) Properties related to Mix Design .
1.Workability of concrete mainly depends upon a)Type of
aggregate, such as rounded ,angular , flaky etc. b)Grading of
course fine aggregates. c)Quality of cement paste in the mix.
d)Consistency of the paste. e)Max size of aggregate also influences
workability. f )Strength of concrete depends on many parameters ,
such as quality and quantity of cement & water grading of
aggregates Mixing ,Placing , and compacting ,curing etc. How ever
W.C.R. is the key parameter which affects strength of concrete.
g)The cement content per m3 of concrete is calculated from free
water cement ratio and the quantity of water required per m3 of
concrete (IS 10262 ) For Max size of aggregate of 40mm; Quantity of
water will be -- 165litres (kg) Sand content 30% of absolute Volume
of total aggregates . The cement content will be = Quantity of
water W.C.R. = 165 = 367 kg . 0.45
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B. Fine and Course Aggregate Cement After obtaining cement
content , water content the percentage of fine aggregate to total
aggregate in terms of absolute volume , are calculated. Fine
Aggregate V = { W+ C + 1 fa } X 1 . Sc p sfa 1000 Course Aggregate
V = { W+ C + 1 Ca } X 1 . Sc 1-p Sca 1000 Where , V = Absolute
volume of fresh concrete . W = Mass of water per m3 of concrete . C
= Mass of cement per m3 of concrete . Sc = Specific gravity of
cement , say 3.15. P = Ratio of Fine aggregate to total aggregate
by absolute volume. fa,ca = Total Quantity of Fine &course
aggregate per m3 of concrete. Sfa, Sca = Specific gravity standard
surface dry fine &course aggregate is and 2.6 respectively.
-
C. DATA FOR MIX DESIGN/DESIGNS:
1. Mix to be designedM20 :with aggregates of maximum size
20mm2.2. Characteristic compressive strength of concrete at 28
days(fck).:For M20, it is 20N/sqmm.3. Desired degree of
workability:Corresponding to a compaction factor of 0.90.4. Type
and maximum size of aggregate supplied :Granite, angular 20mm and
down.5. Expected degree of quality control in the
field.:Good.6.Target mean compressive strength of concrete at 28
days.:For M20 it is 27.6N/sqmm7.Type of exposure.:Moderate.
* The classification of degree of quality control a per
IS10262-1982 (Reaffirmed 1999), provides for good as carefully
stored cement and periodic tests, weigh batching of all materials,
controlled water, graded aggregate supplied, occasional grading and
moisture tests, periodic Check of workability and strength,
intermittent supervision, and experienced workers.
** IS456-2000 describes moderate as concrete surfaces sheltered
from severe rain of freezing whilst wet. Concrete exposed to
condensation and rain. Concrete continuously under water. Concrete
in contact or buried under non-aggressive soil/ground water.
Concrete surfaces sheltered from saturated salt air in
coastalarea.
-
D. DESIGN MIX:To satisfy the requirements mentioned in the data
for mix design the proportion by weight listed in Table-6 has been
arrived at, with marginal adjustment of trial mix for M20 grade of
concrete using aggregates of 20mm down. A number of trial castings
have been made and the best suitable proportion based on
reproducibility of 28-day compressive strength has been
furnished.
E. RECOMMENDATIONS:Compressive strength test results of the
trial specimens cast in our laboratory are furnished in Table-6.It
can be seen that 28 day strength is greater than the target mean
compressive strength indicated in item C. As such, it is
recommended that the concrete mix proportions indicated in Table-6
be adopted at site.
-
F. REMARKS:The design mixes are applicable only for those
ordinary Portland cements whose properties are similar to the one
supplied to us for conducting the mix designAll the materials shall
be weigh batched. Suitable corrections are to be applied for weight
of aggregates, is they are not saturated and surface dry.The bulk
density and specific gravity of materials to be used shall be
conformed by testing of such materials from time to time. If any
deviations in the above parameters are observed, suitable
corrections for proportions shall be applied at site.Suitable
correction is to be applied to water cement ratio, if the
aggregates are not saturated and surface dry.Minor adjustments in
water cement ratio (on the lower side)may be carried about in
actual work to get the desired slump, if necessary.The sand to be
used shall be free from all deleterious materials like silt, clay,
mica and other organic impurities. the gradiation shall be same as
that used in the design mix.The coarse aggregates used shall
conform to the graded aggregate requirements as given in
IS383-1970(Reaffirmed-2002).At site, it is suggested to use
suitable vibrators for compaction.The quality of water to be used
for concreting shall conform to IS456-2000.In the design
calculations, the degree of quality control considered is good.
Hence, it is mandatory to exercise at least the same degree of
quality control in the actual work.
-
G.REFERENCES:
1.IS10262-1982 (Reaffirmed 1999)Recommended guidelines for
concrete mix design2.SP23(S&T)-1982Handbook on concrete
mixes3.IS456-2000Code of practice for plain and reinforced
concrete.4.IS516-1959(Reaffirmed 1999) Method of test for strength
of concrete5.IS383-1970(Reaffirmed 2002)Indian standard
specifications for coarse and fine aggregates from natural sources
for concrete.6.IS1199-1959(Reaffirmed 1991)Indian standard
specifications for method of sampling and analysis of
concrete.7.IS269-1989(Reaffirmed 2000)Indian standard
specifications for 33grade ordinary Portland
cement.8.IS8112-1989(Reaffirmed 2000)Indian standard specifications
for 43 grade ordinary Portland cement.9.IS 12269-1987(Reaffirmed
1999)Indian standard specifications for 53 grade ordinary Portland
cement.10.Krishna Raju. N.Design of concrete mixes, M/s. CBS
Publishers and Distributors, Delhi.11.Neville, A.MProperties of
concrete.
-
READY MIX CONCRETE 1) BATCHING : In batching concrete , quantity
of both cementand aggregate shall be determined by mass . Admixture
if solid by mass , liquid admixture involume , water shall be
weighed or measured byvolumein calibrated tank (IS 4925). This
batching is used for small project sites. 2)R.M.C. : Ready mix
concrete shall be sourced from readymixed concrete plants as per
(IS 4926) forlarge and medium project sites. Concrete is produced
from a centralizedmonitors weigh batching , water cement ratio
,dosage of admixture , moisture cementetc. with precision.
-
FLOW CHART FOR CONCRETE MAKING BATCHING PLANT.
20mm aggregate I10mm aggregate IIC.Sand aggregate IIIR.Sand
aggregate IVCEMENTWATERADMIXTUREAggregate WeighingHopperCement
WeighingHopperAdmixtureWeighingConcrete Mixing UnitTransit
MixreDelivery Chute
-
NATIONAL BUILDING CODE
INTRODUCTION :
1.NBC of India Provides guidelines for regulating the building
constructions activities across the country. A building code or
building control is a set of rules that specifies the minimum
acceptable level of safety for building .2.Revised NBC of India
2005 was formerly released on 16th September,2005.3.NBC serves as a
model code, in building construction works, for adoption by all
agencies like PWD, CPWD etc.4.Building codes are generally intended
to be used by architects and engineers and other agencies.5.The
code mainly contains administration regulations development control
rules and general building requirements, fire safety requirements.
6.St. design and constructions, building services and plumbing
services.7.The main purpose of the building codes is to protect
public interest, safety and general welfare.
-
National building code consists of 10 partseach part
representing one unit as follows.
1.Definitions:2.Administration3.Development control rules and
generalbuilding requirements.4.Fire protection 5.Building
materials6.Structural designs7.Constructional practices and
safety8.Building services9.Plumbing services10.Science and outdoor
display structures
-
UNIT - I Definitions : of all the terms, the section of NBC.
The various terms are 1.Absorption co-efficient.2.Air
conditioning 3.Bearing 4.Cable5.Cavity, wall, column.6.Depth of
manhole, dead load, diameter.7.Factor of safety, fire
resistance.
-
UNIT II .
Administration: Covers applicability of code , organization of
building Department etc.
APPLICABILITY OF CODE:
where a building is erected , the code applies to the design
andconstruction of building.Where the whole are any part of the
building is removed, thecode applies to all parts of the building
whether removed or not.Use of any material are method of design or
constructions shallbe approved by the authority.
ORGANISATION AND ENFORCEMENT:
(1) The building official, shall be appointed by the
authority.
(2) The building official shall appoint, number of offices,
technical assistants, inspectors etc. for administration of the
code.
-
UNIT III.
Development control rules and building RequirementsIt covers
rules proper planning and design ,as the lay out and building level
,to ensure health ,safety ,quality of life.
It provides provision for covered area ,plinth area , amenities
land use classification , FAR , height / size of rooms , kitchens
etc parking etc. Floor area ratio (FAR) limitations ie. floor area
of single storey of building is limited , by the type of
construction and occupancy class . Limitations of areas and heights
of buildings.
Floor Area Ratio = Total area covered of all floors (FAR) Plot
area.
-
LAND CLASSIFICATION
(a) Residential Zone : Purely residential . Residential with
stop lines at ground floor.
(b) Commercial Zone : Local commercial area.
(c) Industrial Zone : Service Industry .General Industry.Special
Industry.
(d) Green Zone : The various building uses and occupation
permitted as given in master plan.
(e) Means of access :Every building /plot shall a but on a
public / private means of access like streets /roads duly
formed.
-
UNIT IV.
FIRE PROTECTION :It covers the requirements of fire prevention
and fire protection of buildings.The code specifies planning and
construction features and fire protection ,features for all
occupancies , that are necessary to minimize the danger to life and
property.
FIRE ZONE :Based on the fire hazard inherent in the building and
structures according to occupancy called as Fire Zones --Designated
as follows .(a) Fire Zone No.1 -- Comprise areas having,
residential ,educational Industrial ,and assembly.(b) Fire Zone
No.2 -- Business. Industrial.(c) Fire Zone No.3 -- Comprise area
having high hazard industrial buildings , storage buildings and
building for hazardous uses.
-
A high rise building construction shall be provided withfire
protection, measures.
(a) Drums filled with water of 2000 Ltrs of capacity with two
fire buckets in each floor.(b) A water storage tank of 2000 Ltrs
capacity which may be used for other construction purposes also.(c)
Maximum height related to width of street facing the building and
the local fire fighting facilities available.(d) Fire detection /
extinguishing system automatic fire detection and alarm facilities
to be provided.(e) Static water storage tanks exclusively for fire
fighting to be made available.(f) The code gives the minimum
requirements for fire fighting installation depending upon the type
of building of occupancy.
-
UNIT V.
BUILDING METERIALS :
1.Cement.2.Aggregates.3.Stones.4.Bricks,
Blocks.5.Timber.6.Precast concrete products.7.Bitumen & Tar
products.Code list out different IS codes for the materials.
-
UNIT VI.
STRUCTURAL DESIGN:
1.Basic design loads for different occupations.2.Foundations:
Building foundation such as raft, pile and other foundation systems
to ensure safety and serviceably without exceeding permissible
stresses of materials of foundation and SBC of supporting
soil.3.Wood : use of structural timbering structures 4.Masonry:
Covers the structural design aspect of un reinforced load bearing
and non load bearing walls.5.Concrete: Plain and reinforced
concrete. Code gives different grades used in concrete with fck at
28 days. M10 -- fck -- 10 N/ mm2 M15 -- fck -- 15N/mm2 Properties
of concrete like workability of concrete, durability, mix
proportion, form work, considering certain parameters. 6.Steel:It
covers the use of structural steel in general building construction
including use of hot rolled steel sections, steel tubes.
-
UNIT VII.
CONSTRUCTION PRACTICES AND SAFETY This covers constructional
practices in building ,handling materials and safety personal
during construction operations for all elements of building.This
code covers the construction practices to be adopted like Planning
,storage , stacking and handling practices. Common hazards during
walling.
UNIT VIII.
BUILDING SERVICES .Lighting and ventilation.Electrical
installation.Air conditioning and heating.Acoustics ,sound
insulation and noise control.Installation of lifts and
escalators.
-
UNIT IX.
PLUMBING SERVICES
Water supply. Drainage & sanitation.
BUILDING RULES Govt. from time to time prescribed rules for the
construction of building to protect the interest of public.Rules
vary from place to place and from state to state.Restriction on
minimum building plot size.Permissible heights and set backs of non
high rise building.
REQUIREMENTS FOR HIGH RISE BUILDINGS . (1) Minimum size of plot
for high rise building --- 2000sqm. (2) Minimum abutting road
widths and alround open space for high rise building shall be
followed.