Concrete Construction Terminology

8/13/2019 Concrete Construction Terminology

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A

ABRASION RESISTANCE:The ability of a concrete surface to withstandsurface wear from machines and other materials.

ABRAMS LAW:A rule stating that with given concrete materials and

conditions of testing, the ratio of the amount of water to the amount of

cement in the mixture design determines the strength of the concrete. (

Water to Cement Ratio ) ACCELERATORS- Chemicals, which increase the rate of hydration, shorten

setting time as well as increase the rate of hardening and strength

development.These products are most often applied in cold weather

applications.

ADMIXTURES:Materials and chemicals added to a concrete mix designwhich can increase strength, workability, lower freezing points,

accelerate or decelerate setting time, entrain air or otherwise affect the

placement, and curing of concrete.


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AGGREGATE- Inert materials, such as crushed limestone, sand, coral, and

gravel, which serve as filler materials and can add significantly to the

compressive strength of concrete. The type of aggregate is normally

dictated by the availability of natural resources and the function ofthe slab or wall.

AIR ENTRAINING AGENTS - Additives which cause the creation of minute

air bubbles in the concrete mixture. This increases workability and frost

resistance and allows for the expansion of the concrete without excessive

cracking


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B

BACKFILL - Earth or other material used to replace material removedduring excavation in preparation for the construction of concretewalls, slabs,culverts, pipelines, trenches or bridge abutments.

BATCH PLANT - An operating Installation with the equipment andmaterials required to mix and batch concrete Some plants are portable

and are capable of installation on the job site. BLEEDING - A term used to describe the rising of excessive water to the

surface of a concrete slab. This is a normal process, which can becontrolled by the addition of water reducers or other admixtures.

BONDING AGENTS - Chemicals used to insure the adhesion betweennewly poured concrete and existing substrates. These products are

manufactured both in a two-part epoxy and a one part latexproduct. Epoxies are recommended for areas where adhesion could bedifficult.

BUG HOLES - Holes left in the surface of formed concrete or grout, whichreflect the location of aggregates, snap ties, or air products.


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C

CALCIUM CHLORIDE - A chemical used to accelerate the hardening of

concrete. The chemical is added to concrete mixtures during frost to

acceleratethe rate of heat build up in the mixture, therefore increasing

setting and hardening rates

CAST IN PLACE CONCRETE:Concrete, which is poured in forms erected at

its permanent location and allowed to harden and cure in this position.

CASSON:A foundation or support system whereby cavities are drilled in

the earthen substrate and filled with concrete.

CEMENT:An ingredient in concrete, which is made by the burning of clay

and crushed limestone. CEMENT FACTOR:The number of bags or cubic feet of cement used in

a cubic yard of concrete.

COLD JOINT: A stop in a pour, usually keyed, where newly poured

concrete is placed adjacent to concrete which has set or begun to set.


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COMPACTION:The density required on the surface, which concrete is tobe poured. Compaction insures that the slab does not crack in areaswhere there is a soft under surface.

COMPRESSIVE STRENGTH:The measure of maximum resistance to load orweight. This factor is measured in Pounds Per Square Inch ( PSI )

CONCRETE CURING:The process of hydration, which allows the retentionof moisture in a concrete mix to allow the attainment of maximumcompressive strength. The prevailing specification for liquid membranecuring compounds is ASTM C-309. The following stipulations are requiredto meet this specification:

CONCRETE JOINTS:Designed breaks or separations in a concrete pourdesigned to allow for expansion and contraction of the concrete andminimize or control cracking in a concrete pour.

Types of Concrete Joints:

Expansion Joints: A designed separation between newly poured concrete structures at critical

intervals ( usually no more than 20 ft. apart ) intendedto allow for expansion and contraction in the concrete due to temperature changes. The absence ofthese joints will allow excessive cracking.

Construction Joints: A joint formed by construction between two successive placements ofconcrete. Examples are column bases or pouring new slabs against existing concrete.

Control Joints: A joint formed by sawing, tooling or grooving, which permits the uniform crackingof concrete. Joints must be sawed as soon as the concrete surface will support the weight of themachine used to saw the joints in order for the joints to be effective.


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CURED CONCRETE:Concrete which has reached its maximum

compressive strength.

CUM-A-LONG:A rake or tool used to move concrete around during

placement.

CYLINDER TEST:A laboratory test which determines the compressive

strength of an actual field sample of concrete which is usually 6 inches in

diameter and 12 inches high in length. Samples are cured and then

compressed in a hydraulic ram to measure the amount of pressure

required to fracture the cylinder.


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D

DEFLECTION:Any movement or variation from the intended grade line of

the slab, beam or other structure.

DYNAMIC LOAD:A load or resistance, which is not static or stationary,

such as the moving live load which exist in a earthquake or hurricane.


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F

FINISH:The act of smoothing or impacting the desired texture on the

surface of concrete. The texture or smoothness of a surface after

finishing operations and screeding has been performed.

FLOAT:A tool, wooden or metallic, used in finishing operations to impart a

relatively level surface.

FLOATING:The process of spreading plaster, stucco or concrete surfaces to

a an equal thickness by the use of a wooden board or magnesium tool.

FLOATING SLAB:A special type of foundation made to carry the weight of

a superstructure, which is to be erected on swampy or unstable soil.

FLY ASH - A substitute for cement, ( not to exceed 25% of the weight ofthe cement ) which reduces shrinkage and retards setting time, thus

Increasing working time.


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FORMS: A temporary structure or mold for the support of concrete while

it is setting and gaining sufficient strength to be self -supporting.

Modular or Hand Set Forms - Smaller forms designed to be placed by

hand. They are produced in various heights and lengths in order to beused in specific applications.

Crane Set Forms ( Gang Forms ) - Larger forming systems which are used on

mass pours and require the use of heavy lifting equipment to be placed in

position.

Slip Form - A form, which is pulled or raised as the concrete is placed. It generally

moves horizontally to lay concrete evenly for highway pavement but can movevertically for concrete walls.

FOUNDATION:The entire substructure below the first floor frame of a

building including the footings on which the structure rest.

FOOTING:The foundation for vertical walls or the area of the slab

designed to support the weight of the roof and wall structures andtransfer weight the weight of the building to the ground.

Continuous Footing: Usually runs the perimeter and below weight bearing interior

walls.

Isolated Footing: Individual structures designed to support the weight of columns

throughout the structure.


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G

GRADE: The slope or ground level of a concrete slab, building or roadbed.

Slab on grade is the slab poured on the ground level of the structure.

GRADE BEAM:A horizontal load bearing foundation member supported

on each end like a standard beam. Not ground supported like a

foundation wall or footing.

GRADING:Modification of the earthen or rock surface by cuts, fills or

both. Normally done by mechanical equipment for gross work and shovel

for more detailed work.

GREEN CONCRETE:Concrete which is in its earliest stage of curing and

has not hardened appreciably. Typical pours take 28 days to cure.


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H

HAUNCHING:The increased depth of a beam or slab near supports or

footings to increase its strength and load bearing capability.

HEADWALL:A wall of any material at the end of a culvert or drain to serve

one or more of the following purposes:

Protect Fill from Scouring or undermining.

Increase hydraulic efficiency by diverting water flow

Serve as a retaining wall

HEAD PRESSURE:This term designates the capacity of a liquid circulator or

the pressure at which a pump can induce the flow of a liquid. The rating

is usually expressed in foot lbs. Of pressure

HIGH DENSITY CONCRETE:Concrete of exceptionally high unit weight,

usually obtained by the use of heavyweight aggregates.


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HIGH EARLY STRENGTH:Concrete which through the use of high early

strength cement or admixtures, is capable of attaining a specified strength

at an earlier age than normal concrete. It is frequently used when pours

are made in low ambient temperatures.

HYDRAULIC CEMENT:A type of cement or mortar which is capable of

hardening under water.


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I

INTRAGAL WATERPROOFING:A term for waterproofing concrete by

including a waterproofing admixture In the mix design.


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J

JETTING:A method of sinking piles with the use of high pressure water or

air jets. This method is used very commonly in marine applications where

pile-driving machinery is not practical.


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K

KEYWAY: A recess built into a lift or placement of concrete, which is filled

with the concrete from the next pour, giving shear strength to the

joint. This joint is usually formed with 10 metal strips and stakes.

KRAFT PAPER:A type of strong, water resistant brown paper, which can be

used in several construction applications, the most frequent of which is a

curing paper for freshly poured slabs.


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L

LASER LEVEL:An electronic devise which uses a laser light beam to define

and exhibit the specified grade level.

LASER SCREED:An electronic, self-propelled machine which moves

concrete to the specified grade through the use of laser light beams as

well as self-contained floating and finishing equipment.

LIGHTWEIGHT CONCRETE:A mixture with substantially lower unit weight

and compressive strength than concrete made with crushed rock or stone

aggregate. Normally used on upper floor levels or roof tops where weight

is a factor.

LOAD BEARING WALL:Any wall, which bears its own weight as well asthe weight of a ceiling or roof. A wall built to withstand wind resistance.


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M

MODULUS:A unit of measure used in describing the strength of a

material.

MODULUS OF ELASTICITY:The unit of measurement or ratio of normal

stress to corresponding strain under movement.

MONOLITHIC CONCRETE:Concrete cast with no joints other thanconstruction joints. A slab poured in a continuous uninterrupted manner.

MUDSLAB:A two to six inch slab below a structural concrete floor or

footing over soft or wet soil.


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N

NON-SLIP FLOOR:A concrete floor surface which has been roughened by

treatment with iron or synthetic filings, carborundum powder or the

placement of indentions in the surface while the surface is still wet.

NO-SLUMP CONCRETE:Concrete with a slump of one inch or less.


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P

PAN AND BEAM FORMING:A prefabricated form in a pan shape, used in

conjunction with concrete floor joist. Used most commonly for slab

pourings on multi-story structures.

PARAPET: A protective railing or low wall around and along a roofs edge

line.

PEA GRAVEL: Screened gravel, which most particles will pass through a

3/8 screen.

PLACING DRAWINGS:Detail sheets, usually provided by reinforcing steel

fabricators, to aid in the correct installation of reinforcement steel.

PLASTICITY:The measurement of a substances ability to remain in aplastic or workable state. ( The ability to be deformed or shaped ) An

index of

working characteristics.


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PILE: ( PILING )A long timber, concrete or steel structure jetted or driven

into the ground for the purpose of supporting building foundations.

PILE CAP:A structural member placed on and usually attached to the top

of a piling or group of pilings and used to transmit loads to the piling orgroup of pilings. It can be constructed of poured concrete, timber or steel

beams.

POLYMER CONCRETE:A concrete created from the use of synthetic

materials as opposed to normal Portland cements. Polymers allow a much

smoother finish as well provide strength. PORTLAND CEMENT:

Type 1: Standard Portland cement. A general purpose

cement for a variety of construction applications.

Type II: A modification of Type 1, which is resistant to

Sulphate attacts and a decreased rate of heat

evolution.

Type III: A high early strength and quick hardening cement.

Type IV: Designed for a low heat hydration.

Type V: Designed for extreme Sulphate resistance.


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POST-TENSIONED CONCRETE: A method of stressing reinforced concrete

in which tendons or cables are tightened after the concrete slab is

hardened and put in place.

PRE-CAST CONCRETE:Concrete, which is cast and cured in a location otherthan its final resting Positon and transported to its final position. ( pre-

cast beams, Lintels, wall panels and elevated slabs )

PRE-STRESSED CONCRETE:A process of preparing concrete slabs and

beams for extra strength by pouring concrete mix over tightly drawn steel

cables, steel rods or tendons to provide strong dense concrete.


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R

READY MIXED CONCRETE: Concrete manufactured for delivery according

to specific mix designs to a purchaser in a plastic and unhardened state.

REINFORCED CONCRETE:Concrete with added materials such as rebar,

wire mesh, fiber mesh, dowel bars, expanded metal fabric or cold drawn

wire cable, which act together with the concrete to resist external force.

RETAINING WALL:A wall built to prevent dirt, rock or other matter from

eroding on to construction areas.

RUBBED FINISH:A finish obtained by application of Portland Cement, sand

and water or other cementitious compounds to fill bug holes or other

deformities on a

Freshly poured concrete surface.

RUBBLE CONCRETE:Concrete made from rubble and concrete debris from

demolished surfaces.


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S

SCARIFYING:Disruption of the smooth surface of concrete by creating scars,dents and a generally rough surface to remove any chemical bond inhibitorsand permit the acceptance of bonding, sealing, adhesive or other coatingmaterials.

SCREED:a. The process of leveling or finishing the surface of a concrete slab.This can be accomplished by hand as well as sophisticated machinery. b. atool or machine used to level a concrete surface.

SCREED PIPE:A round steel pipe, usually 1 in diameter, used to identify thegrade level of freshly poured concrete. The pipe is used as a straight edge andpulled along the surface of the concrete.

SET:The condition reached by concrete, mortar or cement when it has lost its

plasticity to the degree that it stiffens and begins the hardening process. SHOP DRAWINGS:Incidental drawings furnished by reinforcement suppliers

and equipment manufactures that conform to the original architectural andstructural drawings. They illustrate how specific portions of a project blendand work in sequence. They also give specific installation instructions.


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SHOTCRETE:Mortar, concrete or other cementitous materials conveyed byair pressure through a hose at high velocity onto a surface for stabilization,water and debris control.

SHRINKAGE:A decrease in volume and mass caused by temperature and

chemical changes in concrete, mortar and grout during the curingprocess. It can be controlled with admixtures.

SLAB ON GRADE:A non-suspended, ground supported concrete slab,usually reinforced, on the lowest or primary level of a project.

SLUMP:The measure of the consistency of concrete rated in terms ofinches. A mixture with a 3 slump will have less flow ability than a mixture

with a 9 slump. Higher slumps are required when pouring walls to insurethat the concrete penetrates to the bottom of the form and completelysurrounds the reinforcement steel. High slumps are also required whenpumping is required. Higher slumps are achieved by the addition ofadmixtures, which increase flow ability without decreasing strength. Theslump is measured by the use of a slump cone.

SLUMP CONE:A cone shaped mold with a base diameter of 8 inches and atop diameter of 4 inches and a height of 12 inches. A sampling of concretemixture is placed in the cone and the measure of slump is measured bythe decrease in the height of the sample statue once the cone is removedfrom the sample.


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STRENGTH:The measure of a materials ability to resist load or stress.

SUBGRADE:The uppermost material of a substrate on which concrete or

asphalt is to be placed. The foundation for pavement or asphalt

structures. SUBSTRATE: The base or lower surface on which a substance is to be

applied. An earthen substrate is the normal substrate for poured in place

concrete.


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T

TRANSIT:An Instrument commonly used by surveyors for identifying levels

an measurements for project lay outs.

TROWELING: The smoothing and compacting of the uniformed surface of

freshly poured concrete.

TROWELING MACHINE:A motor driven device, which operates orbitingsteel blades on radial arms from a vertical shaft for the purpose of

smoothing and compacting freshly poured concrete.


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U

ULTIMATE STRENGTH:The maximum resistance to load that a structure is

capable of developing before failure occurs.


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V

VIBRATION:The use of a mechanical device to facilitate the consolidation

of concrete in deep pours or pours with a very low slump.

VIBRATOR:An electric, hydraulic or gasoline powered tool used to insure

consolidation of concrete during a deep pour in a wall or slab. It consist

of a power source, usually an electric motor, a whip on variable length

shaft, and a head on the end of the shaft opposite of the motor, which

vibrates and causes concrete to move down and around

reinforcement. Wall mounted models, which attach directly to the side of

metal forms are also available.

Concrete Construction Terminology

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