ACKNOWLEDGEMENT
1. INTRODUCTIONThe site at which we were taken the 30 days
practical training arranged by our college is a Tehsil building
under Public Work Department.Name of Project:- Construction of
Tehsil BuildingCost of Project: - Rs. 175 lakhsName of Chief
Engineer:- Shri N.M AgarwalAbout the Building:-This building is
constructed in the plot area of 5733.44 sq.mIt is a office
building, constructed by Public Work Department.1. This campus has
one block of Type -I quarters (two storeyed).
2. Two blocks of type II quarters (two storeyed) with parking
space at ground floor instead of one quarter.
3. Two blocks of Type - III quarter (Duplex Type) attached
garrage and servant quarters.
4. Five blocks of Type IV Quarters (Duplex type) attached
garrage and servant quarters.
This campus is planned with two Toilets and two small one
community centre, one over Head tank, electric substation and rain
water harvesting system as shown in layout plan of the campus.2.
STRUCTURAL SYSTEMS FOR BUILDINGS2.1 INTRODUCTION
Choice of an appropriate structural system for a given building
is vital for its economy and safety. It is an important decision
which is to be taken by a senior structural engineer. Small
buildings like houses, etc. generally use load bearing brick walls
with reinforced concrete floor slabs. For taller buildings,
reinforced concrete frames in both the principal directions are
provided with brick walls used as only filler walls. For still
taller buildings, frames with shear walls will be provided to
resist both the vertical and the horizontal loads. Likewise, more
intricate and innovative structural systems may be thought, in the
case of unusual buildings.
2.2 BUILDINGS OF DIFFERENT TYPES
2.2.1 LOAD BEARING MASONRY BUILDINGS:Houses, hotels and similar
small buildings are built with load bearing brick walls with floor
slabs being cast in reinforced concrete. This system is suitable
for buildings up to four storeys or less in height. It is quick in
construction and economical is cost. However, care shall be taken
to arrange walls over walls in plan and openings in walls shall be
restricted. Bricks shall be of a crushing strength of 100 kg/cm2
minimum for four storeys, but this value can be 75 kg/cm2 for two
storeys or less. Bricks walls with reinforced concrete floor slabs
are adequate for vertical loads. This system also serves to resist
horizontal loads like wind, earthquakes or blast, by way of
box-action in plan. Further, to ensure its action against
earthquake, it is necessary to provide horizontal bands and
vertical reinforcement in brick walls as per IS : 4326. In some
buildings, 115 mm thick internal walls in brick are provided. As
115 mm thick walls are incapable of supporting vertical loads,
beams have to be provided along their lengths in order to support
the adjoining slab panels and the weight of 115 mm thick brick
walls. These beams are to rest on 230 mm thick walls or reinforced
concrete columns in required, resulting in a mixed system of load
bearing brick walls with reinforced concrete columns wherever
necessary. IS: 1905 is the code governing the design of brick wall
structures.2.2.2 FRAMED BUILDINGS:Reinforced concrete frames,
provided in both the principal directions are effective in
resisting both the vertical and the horizontal loads. The brick
walls are to be regarded as non-load bearing filler walls only. The
spacing of frames varying from 4.0 m to 7.0 m or more is closely
related to the function of building. The slab thickness should be
as close to 100 mm as possible. This can be achieved by
providing
Subsidiary beams in addition to the frame beams. The finishes
and the partition walls should be kept light
In weight. This is important for multistoried buildings in order
to reduce the dead load. This system is suitable for buildings of
more than four storeys. But, in certain blast-or earthquake prone
areas, even single or double storey buildings are made framed
structures for reasons of safety. Single storey buildings of large
storey heights (5.0 m or more), like electric sub-stations, etc.
are also made framed structures, as brick walls of large height are
slender and these may not be relied on to support vertical
loads.
When the lifts are provided, the optimum number of storey is
eight, in order to make full use of lifts. For eight to twelve
storeys, it is advisable to avoid all reinforced concrete walls,
even for lift-wells, in order to avoid undesirable centre of
rigidity, which will interfere with the distribution of the
horizontal load to various frames. In earthquake prone areas,
columns should be made square in size, as earthquake is to be
checked in either principal direction. Rectangular columns should
be provided in wind-dominated areas, with the long side of the
columns being kept parallel to the short side of buildings. Proper
sizing of columns and beams and spacing of frames in either
principal direction are crucial aspects affecting economy.
2.2.3 PARTLY FRAMED AND PARTLY LOAD BEARING:When is two storied
or more, the foundation section is become large and uneconomical,
we design the structure as partly framed and partly load bearing to
decrease the cost of the foundation work.3. CONTOUR PLAN OF SITE3.1
Contour plans: These are graphical representation of the lay of the
land. They show the degree of slope on a site. They typically
relate back to asite datumreferred to as a TBM (temporary
benchmark) and may also relate to AHD (Australian height datum).
They can be used to determine the extent of cut and fill needed the
height of retaining walls, and the overall finished height of
buildings referenced back to natural ground level.To produce a
contour plan a surveyor takes a series of levels over the site at
regular grid spacing. These readings are recorded in a surveyor's
log book and converted to RLs (reduced levels), which are plotted
onto a grid overlaid on the site plan. A draftsperson can then draw
lines of best fit between equal RLs. This gives lines that
represent each contour interval, e.g. RL 5.500. Any feature
matching this contour will have a level of RL 5.5 m.4. LAYOUT PLAN
OF PROJECT4.1 SITE PLAN AND PLANING OF BUILDINGTheplanning ofthe
building hasthemostimportant roleinthecivilengineering because well
designedbuildinghas the comfort and good working conditions forthe
people wholive and workin it. The projecton which I take training
it is aconstructionof residential buildings. Thisbuilding is
designed very carefully by keeping the following views:- Swimming
pool.
Aerobics and yoga room. Media rooms for watching movies
etc.40-50 seats.
Sports lounge.
Kitchen and party room equipped with electricbarbecue.
Library.
Kids play area.
Car Parking.Thereare theenvironmentalconditionsis sunshiny
andhotarid zone,good rainfall goodneighboring conditions. The
facingof thebuilding is south.
Figure 1 :- Layout plan of site
Figure 2 :- Layout plan of site
5. BRIEF SPECIFICATION5.1 Foundation & Plinth(a) 150 mm
thick concrete 1: 5: 10 (1 cement: 5 coarse sand: 10 graded stone
aggregate 40
mm nominal size) shall be provided below stone masonry footing
and 75 mm thick
Concrete 1:5:10 below P.C.C footings.
(b) R.R. masonry in cement mortar 1:6 in foundation up to ground
level.
(c) Reinforced cement concrete work with M-25 in plinth
band.
(d) Brick masonry in foundation in cement mortar 1:6 (1 cement:
6 coarse sand) above ground level and up to plinth level.
(e) DPC 40 mm thick with cement concrete 1:2:4.
5.2 Super Structure(a) Brick masonry in cement mortar 1:6 (1
cement: 6 coarse sand).
(b) Half brick masonry of class designation 75 in cement mortar
1:4 (1 cement: 4 coarse sand) for partition walls.
(c) Reinforced cement concrete work with M-25 in columns beams
suspended floors, lintels, stair case etc. & lintel band at
every floor level.
(d) RCC. 1:1.5: 3 in vertical, horizontal fins.
5.3 Door & Windows
(a) Doors:- (i) Door frames shall be of MS T-iron.(ii) 25 mm
thick flush door shutters flats pressed three layers pre laminated
particle board confirming to IS : 3087 Grade - I and pre lamination
conforming to IS : 12823 grade - I type - II one side decorative
lamination in external doors.
(iii) 30 mm thick kiln seasoned and chemically treated hollock
wood paneled shutters with one side decorative lamination in
internal doors.
(iv) 30 mm thick PVC door for WC & bathrooms.
(v) 25 mm thick pre laminated flat pressed three layers particle
board conforming to IS: 12823 exterior grades I type II one side
decorative lamination including IInd class teak wood piping for
cupboard shutters.
(vi) Oxidized M.S. fittings for doors shall be used in T-I to
T-III quarters and Aluminium fittings in T-IV to T-V quarters.
(vii) The kitchen cabinet shutters in type V & VI
quarters.
(b) Windows
(i) Standard rolled steel section factory made ISI glazed
windows with M.S.
handles, tower bolts & wire gauge windows shall be fixed to
kitchen only.
(ii) M.S. grill of shall be provided in all windows and
ventilators.
5.4 Flooring(i) 40 mm thick C.C. flooring in bedrooms, balcony
and staircase.
(ii) 40 mm thick marble chips flooring in drawing room, kitchen,
W.C. & Bathrooms in T-I to III Quarters.
(iii) 25 mm Kota Stone flooring on kitchen platform in type I to
Type III quarters.
(iv) 52 mm thick CC 1:2:4 metallic hardener flooring in
parking.
(v) Cement concrete flooring in staircases of servant qtrs. and
52 mm thick CC 1:2:4 metallic hardener flooring in garage.
(vi) 40 mm thick marble chips flooring with 50% white cement and
50% ordinary cement in T-IV to T-V.
(vii) Granite stone flooring has been taken on kitchen plate
form in Type-V & VI quarters.
(viii) Marble stone Makrana Doongri Adanga flooring has been
taken in all toilets along with skirting in T-V to T-VI
quarters.
(ix) Kota stones flooring in kitchen platform of type-IV,
staircases of type V & VI qtrs.
(x) Chequared terrazzo tiles in type - IV staircases.5.5 Dado(i)
Ceramic tile dado 1500 mm high in bathrooms, 900 mm high in WC's
& 600 mm high above kitchen platform in T-I to IV quarters.
(ii) All toilets shall be provided with 2100 mm high, ceramic
tiles. WC's shall have similar tiles of 900 mm height in T-IV to
T-VI quarters.
5.6 Roofing(i) The roof shall be treated with integral cement
based water proofing as per A.D.A specifications.
(ii) CI Rain water pipe with required fittings.
5.7 Finishing(a) All internal wall surfaces shall be finished
with dry distemper in T -I to T-III quarters.
(b) All ceilings and walls of kitchen, staircase, W.C. &
bathrooms shall be finished with whitewash in T-I to T-III
quarters.
(c) Outer surface shall be finished with Acrylic smooth exterior
paint in T-I to T-III quarter.
(d) All internal surfaces shall be acrylic distempered and
ceiling shall be finished with white wash in T-IV to T-VI
quarters.
(e) All outer surface of type IV qtrs. shall be painted with
acrylic smooth exterior paint & textured exterior Sandtex matt
for type V & VI qtrs.5.8 Misc. Building Works(a) 50 mm thick
Plinth protection with C.C. 1:3:6.
(b) 7 cm wide 11.4 cm brick edging all round plinth
protection.
(c) Water proofing treatment in Kota stone of wall vertical and
horizontal surfaces of depressed portion of WC, toilet &
kitchen in T-IV to T-VI quarter.5.9 Sanitary and Water Supply
(a) White vitreous china W.C. (Indian type W.C. pan) Orissa
pattern of size 4 580 x 440 mm with low level PVC flushing cistern
and European type W.C. with low level PVC flusher cistern in each
toilet block shall be provided as per norms.
(b) White vitreous china wash basin size 550 x 400 mm with
single 15 mm CP brass pillar tap.
(c) Kitchen sink of stainless steel of size 1040x510 bowl depth
178 mm with drain board in kitchen.
(d) CP brass fittings in all quarters and mixer at wash basin
geyser & baths for Type V & VI.
5.10 Development(a) Water supply line of 150 mm dia S & S C
I Centrifugally LA pipe from OHT 100 mm dia. S & S C.I.
Centrifugally LA pipe for main grid and 80 mm dia. S &S C I
Centrifugally LA pipe has been taken for intermediate grid for
qtrs. All the joints to be provided with Tyton rubber gasket.
(b) One U.G.T. having capacity of three lac liters, 65 mm and 50
mm dia. G.I. pipes for horticulture purposes has been taken.
(c) The R.C.C. NP 2 pipe for sewer line of dia. 250 mm, 300 mm
pipe has been taken and connected with existing outside corporation
line.(d) Storm water drains with R.C.C. NP 2 pipes of dia. 250, 300
& 450 mm has been taken and to be connected with the existing
nallah outside of the cam.
(e) All roads of 6 meter. And 4.00 meter. wide has been taken.
6. DESIGN PARAMETERS6.1 The following design parameters were
followed during structural design of the residential
buildings:-
1. For Slabs beams and columns conc. grade shall be of M 25
(design mix) conforming to F.D.A. Specifications.
2. Clear cover for structural members is as follows:Slab20
mm
Beam30 mm
Column40 mm
Footing50 mm
Table no. 13. SBC at 1.2 ml below natural ground level is 10.6
T/sq.m4. Reinforcement shall be TMT bar of grade FE - 415
conforming to IS - 1786.
5. Development length for TMT bars FE 415 Shall be
MixDevelopment Length (LD)
M 25Column LD in Comp.Beams Slab and footings LD in tension.
3341
Table no. 26. Min. Lap length shall be provided as per IS
456-2000.
7. 230 mm thick Brick masonry with bricks of class designation
75 will be in cement mortar 1:6 (1 cement: 6 coarse sand).
8. 115 mm thick brick masonry with bricks of class designation
75 will be in cement mortar 1:4 (1 cement: 4 coarse sand).
9. For footing of column length of footing reinforcement shall
not be less than *LD* from the face of Pedestral of footing in both
the directions.
10. A lintel band of 230 x 200 mm with 4! 12@ as main
reinforcement and 8$ @00 mmc/c as tiles shall be provided at lintel
level subject to checking of reinforcement for openings.
6.2 BRICK WORK
Classification of bricks
Class designationAverage compressive strength in kg/cm2
100100
7575
5050
3535
Table no. 3The bricks of class designation 75 were used in brick
masonry work. The size of bricks used was 22.5 x 11.1 x 7 cm.
The bricks were tested for the following tests:-
(a) Dimensional Test: - The dimensions of 20 bricks were
measured together.
(b) Compressive Strength: - The compressive strength of any
individual brick not falls below the average compressive strength
specified above by more than 20%.
(c) Water Absorption: - The average water absorption of bricks
was not be more than 20% by weight.
(d) Efflorescence: - The rating of efflorescence was not being
more than moderate.6.3 LayingBricks work was laid in English bond.
Half cut bricks were not used except where necessary to complete
the bond. Closers were used near the ends of the walls. A layer of
mortar was spread on full width over the lower course. Each brick
was properly bedded in position by gently tapping with handle of
trowel. Its in side faces were buttered with mortar before the next
brick was laid and pressed against it. On completion of a course,
all vertical joints were fully filled from the top with mortar. The
walls were taken up truly plumb. All courses were laid truly
horizontal and all vertical joints were truly vertical. Vertical
joints in alternate courses were coming directly one over the
other. All connected brick work was carried up simultaneously and
no portion of work was left more than one meter below the rest of
the work.All iron fixtures, pipes, outlets of water, holds fasts of
doors and windows were embedded in mortar or cement concrete as
specified in their correct position as the work proceeds.
6.4 JointsBricks was so laid that all joints were full of
mortar. The thickness of joints were not exceed 1.0 cm. All face
joints were raked to a minimum depth of 1.5 cm by raking tool
during the progress of work, when the mortar was still green so as
to provide proper key for the plastering.6.5 Curing
The bricks work was cured by minimum 7 days. Brick work carried
out during the day was suitably marked indicating the date on which
the work was done so as to keep the watch on the curing period.
Figure 3:- Curing
6.6 Measurements
(i) 23 cm or more thick brick work was measured in cubical
content is metric units.
(ii) Half brick masonry was measured in square meter.7. ABSTRACT
OF COSTS.NO. SUB-HEAD AND ITEM OF WORKAMOUNT
1.SUB- HEAD - I - EARTH WORK2387170
2.SUB- HEAD - II - CONCRETE WORK2211500
3.SUB- HEAD - III - R.C.C. WORK22488880
4.SUB- HEAD - IV - STONE WORK2712130
5.SUB- HEAD - V - BRICK WORK12772670
6.SUB- HEAD - VI - WOOD WORK6188600
7.SUB- HEAD - VII - STEEL WORK4828100
8.SUB- HEAD - VIII FLOORING6308000
9.SUB- HEAD - IX ROOFING2158900
10.SUB- HEAD -X FINISHING7338500
11.SUB- HEAD - XI - MISC. BUILDING WORK954300
12.SUB- HEAD-XII-SANITARY INSTALLATION2775000
13.SUB- HEAD - XIII - WATER SUPPLY2732500
14.SUB- HEAD - XIV- DRAINAGE1308300
15.SUB- HEAD-XV - ROAD WORK2214800
16.SUB- HEAD - XVI- WATER PROOFING534700
17.SUB-HEAD-XVII-RAIN WATER HARVESTING85950
TOTAL in Rs.80000000
Add : 3% Contingencies in Rs.2400000
Grand Total in Rs.82400000
8. DESCRIPTION OF ITEM SUBHEAD WISE8.1 REINFORCED CEMENT
CONCRETE WORK 8.1.1 Form Work
Form work was including all temporary or permanent forms or
moulds required for forming the concrete which is cast-in-situ,
together with all temporary construction required for their
support. Form work was of timber, ply wood, steel as per
requirement at different positions. Form work was of rigid
construction true to shape and dimensions shown on drawings. It was
strong enough to withstand the dead and live loads and forces
caused by ramming and vibrations of concrete and other incidental
loads, imposed upon it during and after casting of concrete. It was
made so rigid by using adequate number of ties and braces. Screw
jacks or hard board wedges, where required were provided to make up
any settlement in the form work either before or during the placing
of concrete. Forms were so constructed as to be removed in sections
in the desired sequence, without damaging the surface of concrete
or disturbing other sections. Props used for centering were some of
steel, timber posts, ballies. In no case ballies were not allowed
less than 100 mm a mid length and 80 mm at thin end. In case of
slab concrete, only steel plates were allowed as shuttering and gap
between two plates were taped to avoid any leakage of cement grout.
Shuttering was measured separately as for walls, suspended floors,
lintels beams, and columns, stairs vertical and horizontal
fins.
Figure 4:- Formwork8.1.2 Reinforcement
Both i.e. cold twisted and thermo-mechanically treated bars of
different diameters starting from 8 mm to 25 mm were used at site.
All reinforcement were clean and free from dust, loose rust, coats
of paints, oil or other coating which reduces the bond with
concrete.
a) Bending and over lapping :- Bars were bent cold, correctly
and accurately to the size and shape as per detail drawings.
Preferably, bars of full length were used. Over lapping of bars,
where necessary was done. The over lapping bars were bound together
at interval not exceeding twice the dia of the bars. The over
lapping was staggered for different bars and located at points,
where neither shear nor bending moment was maximum. In case of
deformed bars the hooks at ends were not necessary. Wherever
facility was available, welding of bars was done in
overlapping.
b) Placing in position:- Reinforcement bars were placed in
position as per drawings. The bars crossing one another were tied
together at every intersection with steel wire 0.90 to 1.6 mm
thickness twisted tight to make the skeleton of the steel work
rigid so that the reinforcement does not get displaced during the
deposition of concrete.
Figure 5:- Reinforcement
8.1.3 Concreting
The concrete was as specified in subhead R.C.C. The proportions
were as specified in the items. The concrete was M25 grade which
was machine batched, machine mixed and machine vibrated design mix.
The ingredients used were mixed by weight as per design which was
got done from lab.
Figure 6:- Concretinga) Consistency : The concrete, which flow
easily into the forms and around the reinforcement without any
segregation of coarse aggregate from the mortar, was used. The
consistency is depending on whether the concrete is vibrated or
hand tamped. It was determined by slump test as described later.b)
Placing of Concrete : Concreting was done after the inspection of
ADA engineer. Labor was not be allowed to walk over the
reinforcement directly. Cover blocks of 20 mm thick were placed
below the reinforcement to provide proper cover. It was necessary
that the time between mixing and placing of concrete was not
exceeding 30 minutes so that the initial setting process was not
interfered with.c) Compaction : Concrete were compacted after
placing, by means of mechanical vibrators. The layers of concrete
were placed that the bottom layer does not finally set before the
top layer is placed.d) Curing : After 24 hours of laying of
concrete, the surface was cured by flooring with water or by
covering with wet absorbent material. The curing was done for 10
days. The bricks work was cured by minimum 7 days. Brick work
carried out during the day was suitably marked indicating the date
on which the work was done so as to keep the watch on the curing
period 8.2 SIZES OF R.C.C. MEMBERS(a) Columns were of three
sizes:
(i) 230 x 230 mm
(ii) 230 x 350 mm
(iii) 350 x 350 mm
(b) Beams were of four sizes:
(i) 230 x 230 mm
(ii) 230 x 350 mm
(iii) 230 x 500 mm
(iv) 230 x 600 mm
(c) Slab thickness was different in different spans as:
(i)S1 = 100 mm thick
(ii)S2 = 110 mm thick
(iii)S3 = 120 mm thick
(iv)S4 = 140 mm thick9. DETAIL OF WORKS AT SITE9.1 EARTH WORK1.
Excavation of 1.2 m deep and 0.9 meter wide was done for wall
footing in general or as per drawing having different foundation
sections. All excavation operation were include excavation and
getting out the excavated matter at least one metre or half the
depth of excavation, which ever was more.
While carrying out the excavation for drains work, care was
taken to cut the sides and bottom exactly to the required shape,
slope and gradient. If the excavation was done to a depth greater
than that shown on the drawings, the excess depth was made good by
filling stiff clay puddle at places where the drains were required
to be laid and with ordinary earth, property watered and rammed,
where the drains were not required to be land.
2. Columns footing were of different sizes as per drawing and as
per design calculations. There were two following common sizes of
footings.
(i) 1.8 m x 1.9 m for 0.35 m x 0.23 m column size.
(ii) 2.46 m x 2.46 for 0.35 m x 0.35 m column size.
There was some combined footing also.
9.2 CONCRETE WORK
The ingredient was used or mixed by proportion on 1:4:8 and
1:5:10 in cement concrete work.
i.e. 1 cement: 4 sand: 8 stone aggregate 40 mm size or
1 cement: 5 sand: 10 stone aggregate 40 mm size
All the ingredients were measured by a steel box of size 35 cm x
25 cm x 40 cm deep by value and mixed together in a mechanical
mixer by adding water slowly up to the required quantity. The
entire concrete was discharged in trenches and was rammed and
consolidated thoroughly. The thickness of concrete under wall was
kept 15 cm and thickness under column footing was kept 8 cm. The
concrete was measured as cubical content unit.9.3 STONE WORKStone
work as random rubble masonry with cement mortar 1:6 (1 cement: 6
coarse sand) was done in foundations over 1:5:10 cement concrete.
The height of stone was used up to 30 cm and stones were hammer
dressed on the face, sides and the beds, to enable it to come into
close proximity with the neighboring stone. Stones were brought to
level course at ground level. Leveling was done with concrete
comprising of one part of the mortar as used for the masonry and
two parts of graded stone aggregate of 20 mm nominal size. The bond
was obtained by using bond or through stones.
Where bond stone of suitable length was not available, cement
concrete block of 1:3:6 mix was used. At least one bond stone was
provided for every 0.5 sq.m. Of the wall surface. Stones were so
laid that all joints are fully packed with mortar and chips.
(The bond stone is a stone of length equal to width of
wall).
Stone Masonry work was cured for seven days.
Figure 7:- Coarse Aggregates
Figure 8:- Fine aggregates10. Rain Water Harvesting10.1
Introduction
In most urban areas, population is increasing rapidly and the
issue of supplying adequate water to meet societal needs and to
ensure equity in access to water is one of the most urgent and
significant challenges faced by decision-makers.
With respect to the physical alternatives to fulfills
sustainable management of freshwater, there are two solutions:
finding alternate or additional water resources using conventional
centralized approaches; or better utilizing the limited amount of
water resources available in a more efficient way. To date, much
attention has been given to the first option and only limited
attention has been given to optimizing water management
systems.
Among the various alternative technologies to augment freshwater
resources, rainwater harvesting and utilization is a decentralized,
environmentally sound solution, which can avoid many environmental
problems often caused in conventional large-scale projects using
centralized approaches.
Rainwater harvesting, in its broadest sense, is a technology
used for collecting and storing rainwater for human use from
rooftops, land surfaces or rock catchments using simple techniques
such as jars and pots as well as engineered techniques.
Rainwater harvesting has been practiced for more than 4,000
years, owing to the temporal and spatial variability of rainfall.
It is an important water source in many areas with significant
rainfall but lacking any kind of conventional, centralized supply
system. It is also a good option in areas where good quality fresh
surface water or groundwater is lacking.
The application of appropriate rainwater harvesting technology
is important for the utilization of rainwater as a water
resource.
To make optimum use of rainwater at the place where it falls,
provisions of rainwater harvesting & conservation has been
taken as per manual drag. No. 27 (Lateral shaft with bore
wells).
10.2 Types of Rainwater Harvesting Systems Typically, a
rainwater harvesting system consists of three basic elements: the
collection system, the conveyance system, and the storage system.
Collection systems can vary from simple types within a household to
bigger systems where a large catchment area contributes to an
impounding reservoir from which water is either gravitated or
pumped to water treatment plants. The categorization of rainwater
harvesting systems depends on factors like the size and nature of
the catchment areas and whether the systems are in urban or rural
settings. Some of the systems are described below.
(i) Simple roof water collection systemsWhile the collection of
rainwater by a single household may not be significant, the impact
of thousands or even millions of household rainwater storage tanks
can potentially be enormous. The main components in a simple roof
water collection system are the cistern itself, the piping that
leads to the cistern and the appurtenances within the cistern. The
materials and the degree of sophistication of the whole system
largely depend on the initial capital investment. Some cost
effective systems involve cisterns made with ferrocement,etc. In
some cases, the harvested rainwater may be filtered. In other
cases, the rainwater may be disinfected.
(ii) Larger systems for educational institutions, stadiums,
airports, and other facilities
When the systems are larger, the overall system can become a bit
more complicated, for example rainwater collection from the roofs
and grounds of institutions, storage in underground reservoirs,
treatment and then use for non-potable applications. (iii) Roof
water collection systems for high-rise buildings in urbanized
areasIn high-rise buildings, roofs can be designed for catchment
purposes and the collected roof water can be kept in separate
cisterns on the roofs for non-potable uses.
(iv) Land surface catchments
Rainwater harvesting using ground or land surface catchment
areas can be a simple way of collecting rainwater. Compared to
rooftop catchment techniques, ground catchment techniques provide
more opportunity for collecting water from a larger surface area.
By retaining the flows (including flood flows) of small creeks and
streams in small storage reservoirs (on surface or underground)
created by low cost (e.g., earthen) dams, this technology can meet
water demands during dry periods. There is a possibility of high
rates of water loss due to infiltration into the ground, and
because of the often marginal quality of the water
collected, this technique is mainly suitable for storing water
for agricultural purposes.11.QUALITY CONTROL AND TESTS11.1 Test for
Fineness of CementApparatus: - IS sieve No. 9, Sieve Shaker, and
Balance with weight box.
Material: - Test sample of cement.
Procedure:-1. Take a 100 gm of test sample of cement.2. Any air
set lamp of cement may be broken with fingers.3. Put a 100 gm
sample of cement in the IS sieve no .9 (95b). Put the sieve in the
sieve shaker and sieve continuously for a period of 15 minutes.4.
The residues retain on the sieve weight and find the percentage of
residue by the following formula:% of residue or fineness =weight
of residue retained on IS sieve x 100
total weight of sample
Table 4 Limit of Fineness
Type of CementOrdinary Portland CementRapid hardening cementLow
heat cement
Residue by weight not to be exceed10%5%5%
Practical Utility:-
Determination of the percentage of fineness of cement is of
great importance, because the strength of cement depends upon its
fineness. More the finer cement more will be quicker action with
water and gain early strength.11.2 Test for Compressive Strength of
CementApparatus: - Compressive strength testing machine, Mould size
15 x 15 x 15 mm, Temping steel rod 0.6 m long and 16 mm in
diameter, Steel pan for mixing the cement.
Material: - Sample of cement, standard sand.
Procedure:-
1.Take 200 gm sieved cement and 600 gm standard sand by
weight.
2.Take p/4+3.0 percent of water in case of standard sand and
p/4+3.5 percent in case of ordinary sand.
3.Mix cement and sand properly in a non-porous mixing pan. Add
water to the mixture and mix until the color of cement mortar
reaches uniformly. The mixing time should not be more than 5
min.
4.The mixture is filled in the cubic mould in three layers. Each
layer is compacted with temping rod.
5.Moulds are kept in damp condition for 24 hrs.
6.Now, the cement block is released from the mould and immersed
in a water tank.
7.After 3 days, 7 days and 28 days the compressive strength of
cement is tested by using the compressive strength testing
machine.
Compressive Strength=Load at Failure x 100
Surface area of block
Limit of Fineness
TimeOPCRapid HardeningLow Heat
1 day-160kg/cm2-
3 days160kg/cm2275kg/cm2100kg/cm2
7 days220 kg/cm2-160kg/cm2
28 days--350 kg/cm2
Table 5Practical Utility:-
This test is performed to determine the load bearing capacity of
cement.
11.3 Test for Compressive Strength of Sample of
ConcreteApparatus: - 15 cm cube mould, temping rod and compressive
strength testing machine.
Material: - Sample of Concrete.
Theory:-
There are different designs of concrete mix such as M20, M25,
M30, M35 etc. In these design mix M stands for mix and no. denotes
characteristic strength of concrete (compressive strength in 28
days) in Mpa.
Procedure:-1. The 15 cm cube is filled with concrete sample.
2. Cube is filled in three layers. Each layer is compacted by
temping rod.
3. Moulds are kept in damp condition for 24 hrs.
4. Now, the concrete block is released from the mould and
immersed in a water tank.
5. After 3 days, 7 days and 28 days the compressive strength of
concrete is testing by using the compressive strength testing
machine.
Compressive Strength=Load at Failure x 100
Surface area of block
6. Compressive strength of concrete is noted and should
approximately be equal to the mix i.e. M30 or M35 whatever
used.Practical Utility:-
This test is performed to determine the load bearing capacity of
concrete .
11.4 Test for compressive strength of BricksNo. of specimen: -
Five whole bricks shall be taken at random from a lot.
Apparatus: - The apparatus consists of compression testing
machine.
Procedure :-1. Pre Conditioning: - The specimen shall be
immersed in the water for 24 hours at 250C to 290C. The frog of the
bricks should be filled flush with mortar 1 : 3 (1 cement : 3 clean
coarse sand of grade 3 mm and down) and shall be kept under damp
jute bags for 24 hours after that these shall be immersed in clean
water for three days. After removal from water, the bricks shall be
wiped out of any traces of moisture.
2. Actual Testing: - Specimen shall be placed with flat faces
horizontal and mortar filled face upward between three 3 ply
plywood sheets each of thickness 3 mm and carefully centered
between plates of the testing machine.
Load shall be applied carefully axially at uniform rate of 140
kg/cm2 per minute till the failure of the specimen occurs.
Reporting the test results: - The compressive strength shall be
calculated in kg/ cm2 as:-
=Max Load at failure (in kg)
Area of bricks (in sq cm)
Average of five results shall be reported.
11.5 Test for Water Absorption of BricksNo. of Specimen: - Five
whole bricks shall be taken from samples as specimen for this
test.
Apparatus: - A balance required for this test shall be sensitive
to weigh within 0.1 per cent of the weight of the specimen.
Procedure:-
(a)Pre - conditioning: - The specimen shall be allowed to dry in
a ventilated oven at a 1100C to 1150C till it attains a
substantially constant weight. It shall be allowed to cool at room
temperature. In a ventilated room, properly separated bricks will
require four hours for cooling, unless electric fan passes air over
them continuously in which case two hours may suffice. The cooled
specimen shall be weighed W1.
(b)Actual Testing: - Specimen shall be completely dried before
immersion in the water. It shall be kept in clean water at a
temperature of 270C + 20C for 24 hours. Specimen shall be wiped out
of the traces of water with a damp cloth after removing from the
water and then shall be weighed within three minutes after removing
from water (W2).
(c)Reporting the test results: - The water absorption shall be
calculated as follow:-
W2 - W1x 100
W 1
Average of five tests shall be reported.11.6 Test for
Efflorescence of BricksNo. of specimen: - For this test 5 dry
bricks should be picked up at random from the lot.
Apparatus: - Apparatus required for this test shall be a shallow
flat bottom dish containing distilled water.
Procedure (Actual Testing):-
The brick shall be placed vertically in the dish with 2.5 cm
immersed in the water. The room shall be warm (180C to 300C) and
well ventilated. When the whole water is absorbed and the brick
appears to be dry, place a similar quantity of water in that dish
and allow it to evaporate as before. The brick shall be examined
after the second evaporation.
Reporting the test results
The liability to efflorescence shall be reported as 'NIL'
'slight moderate', 'heavy', or serious in accordance with the
following definition.
(a) Nil: - When there is no perceptible deposit of
efflorescence.
(b) Slight: - When not more than 10 per cent of the area of the
brick is covered with a thin deposit of salts.
(c) Moderate: - When there is heavier deposit and covering up to
50% of the area of the brick surface but un-accompanied by
powdering of flaking of the surface.
(d) Heavy: - When there is a heavy deposit of salts covering 50%
or more of the brick surface but unaccompanied by powdering or
flaking of the surface.
(e) Serious: - When there is a heavy deposit of salts,
accompanied powdering and / or flaking of the surfaces and tending
to increase in the repeated wetting of the specimen.11.7 BULKING OF
FINE AGGREGATE / SAND (FIELD METHODS)
Two methods are suggested for determining the bulking of sand /
fine aggregate.
Method 1:- Put sufficient quantity of sand loosely into a
container until it is about two third full. Suppose this is 'X'
cm.
Empty the sand out of the container into another container where
none of it is lost. Half fill the first container with water. Put
back about half the sand and rod it with a steel rod, about 6 mm in
diameter, so that its volume is reduced to a minimum. Then add the
remainder and level the top surface of the inundated sand. Measure
its depth at the middle with the steel rule. Suppose this is 'Y'
cm.
The percentage of bulking of the sand due to moisture shall be
calculated from the formula:
Percentage bulking = [(X / Y) - 1] x 100
Method 2:- In a 250 ml measuring cylinder, pour the damp sand
until it reaches the 200 ml mark.
Then fill the cylinder with water and stir the sand well. It
will be seen that the sand surface is now below its original level.
Suppose the surface is at the mark of 'Y' ml the percentage of
bulking of sand due to moisture shall be calculated from the
formula:
Percentage bulking = [(200/Y)-1] x 10011.8 TEST FOR SILT
CONTENTS OF COARSE SANDThe sand shall not contain more than 8% of
silt as determined by field test with measuring cylinder.
A sample of sand to be tested shall be placed without drying in
a 200 ml measuring cylinder. The volume of the sample shall be such
that it fills the cylinder up to 100 ml mark.
Clean water shall be added up to 150 ml mark. Dissolve a little
salt in the water in the proportion one tea spoon to half a liter.
The mixture shall then be shaken vigorously and the contents
allowed settling for three hours.
The height of silt visible as settled layer above the sand shall
be expressed as a percentage of the height of sand below. The sand
containing more than the above allowable percentage of silt shall
be washed so as to bring the silt contents within allowable
limits.
11.9 SLUMP TEST FOR CONCRETE
Apparatus: - Mould shall consist of a metal frustum of cone
having the following internal dimensions:-
Bottom Diameter
20 cm
Top Diameter
10 cm
Height
30 cm
The mould shall be of a metal other than brass and aluminium of
at least 1.6 mm (or 16 BG) thickness.
Tamping rod shall be of steel or other suitable material, 16 mm
in diameter, 60 cm long and rounded at one end.
Procedure:-
The mould shall be placed on a smooth, horizontal, rigid and non
absorbent surface, viz. Leveled metal plate. The operator shall
hold the mould firmly in place while it is being filled with test
specimen of concrete. The mould shall be filled in four layers,
each approximately one quarter of the height of the mould. Each
layer shall be tamped with twenty five strokes of the rounded end
of the tamping rod. The mould shall be removed from the concrete
immediately after filling by raising it slowly and carefully in a
vertical direction. The moulded concrete shall then be allowed to
subside and the slump shall be measured immediately by determining
the difference between the height of the mould and that of the
highest point of specimen.
Result: - The slump shall be recorded in terms of
millimetres.
12 CONCLUSION
Technical education means the education regarding the techniques
are nothing but the practical approach of doing something. So, in
the curriculum of technical studies it becomes necessary to have
the practical knowledge along with the theoretical one.
In case of civil engineering where almost whole of the work is
carried out by the persons who generally dont have the theoretical
knowledge as labor, it becomes more important to be practical
rather than being purely theoretical as in future we are to deal
with these very persons, for this the practical training provides a
platform to develop the skills to communicate with these
people.
The theory is not just applied in the field in the same way as
it appears in the book but it is applied in the most optimum but
the feasible way. So, the training also enables us to get the
practical problems which generally occur in the field and are to be
dealt by the engineering decisions.
So, in a nut shell it can be said that the practical training is
very important part of our curriculum which connects us with the
actual scenario of our field and lets us develop the practical
approach of thinking, analyzing and implementing any problem so it
should be taken very sincerely.
13 REFERENCES Guidance provided by the project Engineer,
supervisor & other staff members. IS 456:2000Indian Standard
PLAIN AND REINFORCED CONCRETE CODE OF PRATICE BOOKS:-(a)R.C.C
B.C.PUNMIA(b)CONCRETE M.S.SHETTY(c)BUILDING CONSTRUCTION -
B.C.PUNMIA
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