BT- CONCRETE AND CEMENT

Concrete

building material made by mixing small stones and sand with limestone, clay, and water; Binding medium and Aggregate; Cement + Sand + Gravel + Water

Cement Paste

Cement + Water

Cement Mortar

Cement + Water + Sand

Masonry Mortar

Cement + Water + Sand + Lime

Reinforced Concrete

Concrete into which steel reinforcing bars have been embedded to impart tensile strength to the construction.

Plain Concrete

Concrete having no reinforcement, or reinforced only for drying shrinkage or thermal stresses.

Pozzolana

natural cement. The Romans made this cement with ash that was blown out of the volcano Vesuvius. it is waterproof and hardens even when it is wet. Roman Concrete

Joseph Aspdin

invented PORTLAND CEMENT in 1824.

William Ward

Built the first reinforced concrete building in the US in Post Chester, New York in 1875

E.L. Ransome

Built the first building to withstand Earthquake and Fire

Compressive Strength, Rigidity, Low Maintenance

Advantages of concrete

Low Tensile Strength, Formworks Required, Heavy and Large

Disadvantages of concrete

Hydraulic Cement

Cement capable of setting and hardening by a reaction with water.

Portland Cement

A HYDRAULIC CEMENT made by burning a mixture of clay and limestone in a rotary kiln and pulverizing the resulting clinker into a very fine powder, named for its resemblance to a limestone quarried on the isle of Portland, England.

Tricalcium Silicate

Portland Cement component responsible for the hardening or early gain in strength of the cement.

Dicalcium silicate

Portland Cement component responsible for the aging or long term gain in strength of the cement.

Tricalcium Aluminate

Portland Cement component responsible for the initial setting of the cement.

Tetracalcium Aluminoferrite

Portland Cement component responsible for the process of cement manufacturing by allowing lower clinkering temperatures

Clinker

the stony residue from burnt coal or from a furnace

Type I

Ordinary Cement for general use. Special properties not Required

Type II

Modified Cement that is MODERATELY sulfate resistant . This is used when Cement is in contact with water.

Type III

Cement with HIGH EARLY STRENGTH. This has reduced curing time and is used where high strength is desired within a week or less.

Type V

Cement that is Sulfate Resistant. This is used when high resistance to sulfate is desired. Used commonly for underwater structures.

Type IV

Cement Low Heat. Used where LOW HEAT OF HYDRATION is desired. Develops strength at a much slower rate, thus resulting in impressive strength. Ex. used in DAMS

Air Entraining Hydraulic Cement

Cement that entrains Air in the mixture, thus creating small bubbles, resulting in lighter concrete.

Portland Blast Furnace Slag Cement

An interground mixture of Portland Cement clinker and granulated blast furnace slag.

Portland Pozzolan Cement

An interground mixture of Portland Cement clinker with pozzolan.

White Portland Cement

A Portland cement produced from raw materials low in iron oxide and manganese oxide, the substances that give concrete its gray color, used in precast concrete work and in the making of terrazzo, stucco, and tile grout.

Masonry Cement

A proprietary mix of Portland cement and other ingredients, such as hydrated lime, plasticizers, air-entraining agents and gypsum requiring only the addition of sand and water to make cement mortar.

Expansive Cement

Special type of cement that increases in volume during setting and retains a portion of such volume after hardening.

High Alumina Cement

An acceleration admixture to Portland Cement

Lime

Slow setting and hardening; this is primarily used to plasticize harsh cements and to add resilience to mortars and stucco.

Gypsum Cement

This is used in plastering gypsum boards and gypsum blocks.

Hydration

Generation of Heat in Cement. Chemical Reaction that takes place when Portland Cement and Water are mixed together.

Setting

This is when cement is mixed with water to form a fluid paste, the mixture will eventually stiffen and harden.

False Setting

This is when the stiffening of a concrete mixture generates significantly little heat.

Heat of Hydration

the heat generated by the process of hydration as during the setting and curing of a concrete mix

2400 kg/m3

Weight of concrete

Normal Weight Concrete

Concrete with compressive strength between 2000 - 8000 psi. Used in structural framings, pavements and floorings; 135 - 165 lbs/ft^3

Lightweight-Structural Concrete

Concrete with resistance to heat flow. Used in Load Bearing Exterior Walls and prestressed concrete; 85 - 115 lbs/ft^3

Lightweight-Insulating Concrete

Concrete that uses aggregates such as perlite, vermiculite, expanded polystyrene, and the like to fill over meta, roof decks, partitions and wall panels. 15 - 90 lbs/ft^3

Heavyweight Concrete

Concrete used for walls of spaces containing radioactive materials. Also used in concrete counter weights. 130 - 290 lbs/ft^3

Cellular Concrete

Concrete that has air bubbles or gas, suspended in the mortar. Usually used for insulating

Gap Graded Concrete

Concrete where aggregates are exposed.

Ferrocement

Constructed of cement-sand mortar over a wire mesh that has been preshaped over a mold.

Fiber Concrete

Concrete with added fibers such as glass, steel used tp control plastic shrinkage.

Nailing Concrete

Concrete with Nail holding strength

No Slump Concrete

Concrete with a consistency corresponding to a slump of 1/4 inch or less.

Porous Concrete

Concrete with no fine aggregates

Tremie

A large funnel with a tube attached, used to deposit concrete in deep forms or beneath water or slurry.

Reinforced Concrete

Concrete into which steel reinforcing bars have been embedded to impart tensile strength to the construction.

prestressed concrete

Concrete into which compressive stresses have been introduced using steel wires or rods.

Posttensioned Concrete

Prestressed concrete in which the pretensioning steel is stressed after the concrete is cast.

Trowelled

Concrete finish where excess mortar is simply cut off (struck) with a trowel and finished with the trowel tooled

Broomed

Concrete finish that makes surface slip resistant. A Broom is dragged accross the surface of the concrete after it has been smoothed.

Exposed Aggregate

Concrete finish where a concrete surface in which the coarse aggregate is revealed

Rock Salt

Concrete finish where Rock salt is sprinkled on top of wet concrete, leaving little pits.

Stamped Concrete

Concrete finish where stamps are used to form a texture

Internally Pigmented

Concrete finish where coloring agents are added to the mixture.

Swirl

Concrete finished achieved by spreading the concrete surface in circular pattern.

Polished

Concrete Finish that grinds and polish the concrete with the use of specialized tools to provide distinct textures.

Aggregate

Granular Materials added to concrete mixture; Fine and Coarse; 60 - 70 % of Concrete Volume

The inherent strength of the concrete relies on the quality of its __________________________.

Fine Aggregate

Aggregate consisting of sand having a particle size smaller than 1/4 in. (6.4 mm); specif. the proportion of aggregate that will pass through a 3/8 in (9.5 mm) sieve.

Coarse Aggregate

Aggregate consisting of crushed stone, gravel, or blast-furnace slag having a particle size larger than 1/4 in. (6.4 mm); specif. the portion of aggregate that is retained on a No. 4 (4.8 mm) sieve.

Expanded Shale

A strong lightweight aggregate obtained by the exfoliation of clay or shale. Also called expanded clay.

Expanded Slate

a strong lightweight aggregate obtained by the exfoliation of slate

Perlite

A volcanic glass expanded by heat to form lightweight aggregate and as loose fill insulation.

Vermiculite

Mica expanded by heat into very light wormlike threads.

a lightweight aggregate

Diatomite

Consists of the skeletons of tiny aquatic plants called diatoms.

Flyash

Fine Particles recovered from waste gasses of a solid fuel furnace.

Water Cement Ratio

The ratio of water to cement in a concrete mix, the main factor which determines concrete strength.

Cement-aggregate ratio

The ratio of cement to aggregate in a mixture, as determined by weight or volume.

Class AAA 1:1:2

Concrete Proportioning for concrete subjected to post tensioning, pretensioning, dams and similar uses.

Class AA 1:1&1/2:3

Concrete Proportioning for concrete under water, retaining walls and elevator shafts.

Class A 1:2:4

Concrete Proportioning for standard mixtures for reinforced floor slabs, beams, columns, arches etc.

Class B 1:2&1/2:5

Concrete Proportioning for medium mixture slab on fill, retaining walls, abutment piers and sidewalks.

Class C 1:3:6

Concrete Proportioning for lean mixture of stone masonry filling, parapet walls and plant boxes.

Class D 1:3&1/2:7

Concrete Proportioning for foot path, walkway and lean concrete.

4500psi

Strength of Class AAA

4000psi

Strength of Class AA

3500psi

Strength of Class A

3000psi

Strength of Class B

2500psi

Strength of Class C

2000psi

Strength of Class D

Hand Mixing

A manual method of mixing concrete done on a watertight platform.

Stationary Mixers

Concrete is mixed at the central yard and delivered to job side in transit mix trucks.

Portable Mixer

Stationary concrete mixer used in smaller concrete jobs.

Paving Mixers

Concrete mixers mounted on crawler treads; usually used for road construction.

Shotcrete

Concrete is shot from a Pneumatic Equipment

Pumped Concrete

Concrete is to be placed high above grade or in a formwork of complex shape.

Ready Mixed Concrete

batched in a stationary plant then hauled to the site

admixture

Any substance other than cement, water or aggregate, added to a concrete or mortar mix to alter its properties or those of the hardened product. Also called additive.

Air Entraining Agent

An admixture that disperses entrained air in a concrete or mortar mix to increase workability, improve resistance of the cured product to the cracking induced by free-thaw cycles or the scaling caused by deicing chemicals, and in larger amounts, to produce lightweight insulating concrete.

Accelerator

hastens the setting and strength development of concrete

Retarder

Slows the setting and strength development of a concrete, mortar or plaster mix

surface active agents

decrease surface tension among molecules of a liquid

water-reducing agent

An admixture for reducing the amount of mixing water required for the desired workability of a concrete or mortar mix. Lowering the water-cement ratio in this manner generally results in increased strength. Also called superplasticizer.

Coloring Agent

Adds color to the product

Dispersal Agent

Additive used to ensure that all particles of cement and water are mixed thoroughly in a concrete setting

Concrete Hardener

an additive which improves the denseness of concrete surface which are subjected to rolling live loads and impact