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169 Cards in this Set
- Front
- Back
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Concrete |
An artificial, stonelike building material made by mixing cement and various mineral aggregates with sufficient water |
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Cement |
A calcined mixture of clay and limestone |
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Natural cement |
-A naturally occuring clayey limestone
-Produces hydraulic cement when pulverized |
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Pozzolan |
-A siliceous material that reacts chemically with slaked lime in the presence of moisture to form a slow hardening cement
-also pozzolana, pozzoulana |
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Tricalcium silicate |
-About the one half volume of portland cement
-responsible for the hardening or early gain in strength of the cement |
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Dicalcium silicate |
-about one quarter of the volume of portland cement
-responsible for the aging or long term gain in strength of the cement |
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Tricalcium aluminate |
-about one tenth of the volume of portland cement
-responsible for the initial setting of the cement |
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Portland cement |
A hydraulic cement made by burning a mixture of clay and limestone in a rotary kiln |
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Type I: normal |
A portland cement used for general conctruction |
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Type II: moderate |
-A portland cement having a reduced content of tricalcium aluminate -construction of large piers and heavy retaining walls |
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Type III: high early strength |
-A very finely ground portland cement having an increased content of tricalcium silicate -used when early removal of formwork is desired or in cold weather construction |
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Type IV: low heat |
-A portland cement having reduced content of tricalcium silicate and an increased content of dicalcium silicate -construction of massive concrete structures, as gravity dams |
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Type V: sulfate resisting |
-A portland cement having a reduced content of tricalcium aluminate, lessening the need for gypsum
-Normally added to cement to retard its setting time |
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White portland cement |
-A portland cement produced from raw materials low in iron oxide and manganese oxide -give concrete its gray color |
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Clinker |
A fused mass of incombustible matter resulting from heating in a kiln |
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Calcine |
To heat a substance to a high temp but without melting |
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Cement paste |
A mixture of cement and water |
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Fine aggregate |
Aggregate consisting of sand having a particle size smaller than 1/4 in. |
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Coarse aggregate |
Aggregate consisting of crushed stone, gravel, or blast furnace slag |
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Perlite |
-A volcanic glass expanded by heat
-Also pearlite |
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Vermiculite |
Mica expanded by heat into very light, wormlike threads |
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Admixture |
-Any substance other than cement, water or aggregate added to a concrete or mortar mix to alter its properties
-Also called additive |
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Air-entraining agent |
Admixture that disperses entrained air in a concrete or mortar mix to increase workability |
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Accelerator |
Admixture that hastens the setting and strength development of a concrete, mortar, or plaster mix |
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Retarder |
Admixture that slows the setting of a concrete |
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Surface-active agent |
-Admixture for reducing the surface tension of the mixing water in a concrete mix
-also called surfactant |
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Water-reducing agent |
-Admixture for reducing the amount of mixing water
-also called superplasticizer |
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Abram's law |
-A law postulating that with given concrete materials, curing and testing conditions, the compressive strength of concrete is inversely proportional to the ratio of water to cement
-D.A Abrams in 1919 |
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Water-cement ratio |
The ratio of mixing water to cement |
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Sack |
-A measure of portland cement
-also called bag |
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Slump test |
A method for determining the consistensy and workability of freshly mixed concrete by measuring the slump of a test specimen |
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Slump |
A measure of the consistency and workability of freshly mixed concrete |
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Consistency |
-The relative ability of freshly mixed concrete or mortar to flow -state of fluidity of the mix |
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Plastic mix |
Flows sluggishly without segregating and is readily molded |
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Dry mix |
-Containing little water or too much aggregate in relation to other components and having little or no slump
-also called stiff mix |
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Wet mix |
Having a relatively high water content and runny consistency |
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Slump cone |
An open ended, truncated cone of sheet metal |
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Compression test |
A test for determining the compressive strength of a concrete batch |
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Cast-in-place concrete |
-concrete deposited, formed, cured, and finished
-also called cast-in-site concrete |
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Time of haul |
The period from first contact between mixing water and cement |
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Placement |
The process of depositing and consolidating freshly mixed concrete |
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Ready-mixed concrete |
Concrete mixed at a batch plant for delivery |
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Shrink-mixed concrete |
Concrete partially mixed at a batch plant |
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Transit-mixed concrete |
Concrete dry batched at a batch plant |
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Agitator truck |
A truck equipped with a rotating drum to prevent segregation |
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Truck mixer |
a truck equipped with a rotating drum and a separate water tank |
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Concrete mixer |
A machine having a revolving drum |
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Buggy |
A cart, often motor driven for transporting heavy materials |
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Core test |
A compression test of a cylinder |
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Direct placement |
Discharging of freshly mixed concrete directly into a form |
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Free fall |
The descent of freshly mixed concrete into a form without the aid of a drop chute |
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Drop chute |
Chute for containing and directing a falling stream |
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Chute |
Include trough or tube for conveying free flowing materials |
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Pneumatic placement |
Delivery of concrete, slurry or plaster by a pipeline or hose |
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Gunite |
-Lightweight concrete construction consisting of a mixture of cement
-also called shotcrete |
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Consolidation |
Process of eliminating voids other than entrained air |
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Spading |
Withdrawals of a flat, spade-like tool |
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Rodding |
Withdrawals of a rod |
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Vibration |
Moderately high frequency oscillations of a vibrator |
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Vibrator |
Electric or pneumatic oscillating tool |
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Segregation |
Separation of coarse aggregate from the mortar or of water |
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Stratification |
Separation of an excessively wet or over vibrated concrete mix |
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Bleeding |
Emergence of excess mixing water |
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Laitance |
Milky deposit |
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Finishing |
Process of leveling, smoothing, compacting and treating a newly placed concrete |
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Screed |
Wooden or metal straightedge |
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Screed |
Firmly established grade strip or edge |
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Float |
Flat tool for spreading and smoothing a fresh concrete |
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Bull float |
A float having a large flat blade |
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Darby |
Long wooden or metal straightedge for smoothing a fresh concrete |
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Trowel |
Any of various flat bladed hand tools |
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Power trowel |
A portable machine having steel trowels |
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Edger |
Trowel having long, curved lip for rounding the edges |
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Pavement saw |
Wheel mounted rotary power saw |
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Set |
Assumption of a rigid or hard state by concrete |
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Cure |
To maintain a newly placed concrete at required temp for the first seven days |
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Heat of hydration |
Heat generated by the process of hydration |
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Hydration |
Substance combine chemically with water |
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Architectural concrete |
Exposed concrete work requiring special care in the selection of materials |
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Dry-shake finish |
A colored finish produced by sprinkling a dry mixture of cement |
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Beton brut |
Concrete left in its natural state after formwork is removed |
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Float finish |
A fine textured finish obtained by smoothing a fresh concrete |
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Broom finish |
A striated finish obtained by stroking a broom or stiff brush |
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Exposed aggregate finish |
Decorative finish produced by sandblasting |
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Trowel finish |
Dense, smooth finish obtained by working a fresh concrete with a steel trowel |
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Swirl finish |
Troweling with a circular, overlapping motion |
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Bushhammered finish |
Coarse textured finish obtained by fracturing a concrete |
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Honeycomb |
Voids on a formed concrete surface |
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Spalling |
-Chipping or scaling of a hardened concrete -also called scaling |
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Crazing |
Numerous hairline cracks |
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Drying shrinkage |
Reduction in volume of concrete caused by loss of moisture |
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Setting shrinkage |
Reduction in volume of concrete caused by hydration of the cement paste |
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Concrete |
Proportioned mixture of cement, aggregate and water |
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Concrete |
A plastic mass which can be cast, molded, or formed into size or shape |
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Setting |
Hardening of concrete is called |
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Mortar, stucco or cement plaster |
Mixed with water and fine aggregate of less than 6mm (1/4") |
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Concrete |
Mixed with water and fine aggregate of more than 6mm (1/4") in size produces |
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Reinforced concrete |
Concrete strengthened by embedded steel |
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Plain or mass concrete |
Concrete without reinforcement |
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Cement |
First developed by the romans by mixing slaked lime with pozzolana |
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Smeaton |
An englishman who rediscovered hydraulic cement |
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Aspdin |
-English bricklayer and mason
-invented and patented portland cement |
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Cement |
Generelly refers to portland cement which is the principal type of cement in use |
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Cement |
-Hydraulic bonding agent used in building construction -fine powder obtained by grinding the clinker of clay |
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Natural cement |
Obtained from natural materials having cement-like structure |
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Artificial cement |
-Available in large and increasing numbers -may be classified as portland cement |
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Portland cement |
-Proper proportions of lime, silica, and iron components -four parts of limestone to one part of clay are basic ingredients |
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Portland cement |
Sold either in cement bags of 40 to 50 kilos weight or in bulk |
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White cement |
-stainless cement -free of iron impurities |
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American society for testing materials |
ASTM |
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1 cu. Ft and weighs 94 lbs |
Each bag of cement is equivalent to |
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94 lb |
Measure of P.C in US |
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87.5 lb |
Measure of P.C. in canada |
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112 lb |
Measure of PC in britain |
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50 kg |
Measure of PC in other countries |
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White portland cement |
-Same material as normal portland except in color -for curtain wall and facing panels |
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Masonry cement or tile adhesives |
-Specially designed to produce better mortar -has good plasticity and workability |
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Waterproofed portland cement |
Produced by adding a small amount of stearate |
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Lime |
-One of the oldest manufactured building material -used as mortar and plaster by the early civilization |
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Egyptians |
Used lime plaster before 2600 bc |
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Romans |
Developed a mixture of lime putty and volcanic ash for the first real cement |
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Quicklime |
Carbonates decompose into carbon dioxide which is expelled |
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Slaking or hydration |
Before quicklime is used, it must be first mixed into water |
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Slaked lime or hydrated lime |
Calcium hydroxide (Ca(OH)2) known as |
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Hydrated lime |
-Mixed with water to make lime putty -used only where slow underwater setting is required |
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Gypsum |
Like lime, was used as a plaster by egyptians, greeks and romans |
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Plaster |
From the greek word for both theraw materials and calcine product |
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Gypsum rock |
Is ground fine and heated to between 325°F to 340°F |
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Plaster of paris |
If pure gypsum is used |
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Hard wall plaster |
-If 39.5% impurities are present -harder than lime plaster |
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Gypsum plaster |
Rendered more plastic by the addition of hydrated lime |
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Fiber or hair |
Sometimes added for greater cohesiveness |
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1400°C to 1450°C |
Required temp for portland cement |
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Tricalcium silicate |
Main ingredient of portland cement |
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Aluminous cement |
-Produces mortar or concrete with high initial strength -made from a mixture of limestone and clay with high aluminum oxide content -calcined at about 1400°C |
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Gypsum |
Added to clinker to retard setting |
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300mm (12") from the ground |
Cement should be stored in shed with a wood floor raised about.... |
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12 sacks in height |
Piles should be limited to... |
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Construction aggregate or aggregate |
Inert mineral fillers |
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Lightweight aggregates |
-ASTM C330 -such as cinders, blast, furnace slags... |
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Pumice |
-Weighing from 25 to 60 lbs per cu. Ft -hard to be handled and mixed without excessive breakdown -undesirable feature is its water absorption |
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Perlite |
-Composed of stable silicates and is inert -durable for use as a lightweight aggregate or for insulation -useful when maximum strength is not required |
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Vermiculite |
Micaceous mineral which expands on application of heat |
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Expanded slag |
-or foamed slag -molten blast furnace slag with controlled quantities of water or stream |
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Cinders |
-Composed of the ash components of the coal -satisfactory for use in concrete but are not particularly weight saving |
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Admixtures |
Come in powder, paste, and liquid form |
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Accelerator |
-principal ingredient are calcium chloride -maximum amount added is 2lbs per bag of cement |
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Retarder |
Principal ingredient include zinc oxide, calcium lignosulfonate, derivatives of adipic acid |
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Waterproofing compounds |
-Reduce the capillary attraction of the voids in concrete -it does not render concrete waterproof |
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Dry cast |
For surface coloring |
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Integral colors |
- for body coloring
-incorporated in the mortar topping |
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Proportioning concrete |
Oldest, the most commonly used the most convenient and the least scientific method |
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One cubic foot |
Each 'part' is equivalent to |
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Batch mixers |
Into which sufficient materials are placed at one time |
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Continuous mixers |
Into which the materials are fed constantly |
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Aerocrete |
-Lightweight, expanded structural concrete
-produced by adding a small amount of metallic aluminum powder
-excellent fire resistive qualities |
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Gunite |
-mixture of sand and cement deposited under high pneumatic pressure
-trade name cement gun |
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Porete |
Portland cement concrete to which a chemical foam is added to generate gases in the process of deposition |
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Haydite |
Processed concrete added with lightweight aggregate |
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Water cement ratio |
Often stated in gallons of water per 94 lb sack of cement |
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Water cement ratio |
Controls the strength, durability and water tightness of hardened concrete |
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Water cement ratio |
Amount of water used per bag of cement |
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Duff A. Abrams |
Abram's law |
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Air entraining agents |
Manufactured from such ingredients as rosin, beef tallow, stereates, foaming agents (soap) |
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Surface active agent |
Aiding in the emulsifying and dispersion of other additives |
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Hydrated lime |
Usually in the proportion of 10 to 15% of the cement by volume |
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Slump |
Reduce its height due to gravity action |
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Hand mixing |
Done on a water tight platform |
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Hardening |
Rather slow process in which the cement and water unite to form compounds that give strength and durability to concrete |
