ANSWERS
- answer-Properties of Concrete
1850 - answer-What year Reinforced Concrete was developed?
18th - answer-What century people regained knowledge of concrete construction
19th - answer-What century did engineering design methods had been developed for structures
of reinforced concrete
28 - answer-Concrete is normally considered fully cured after _____ days
28 - answer-It is generally believed that the specified strength will be reached after ____ days
for ordinary concrete.
6 gallons per 40 kg - answer-The Average water-cement ratio is ____ ________ _______
_____ _____ of cement bag
60% - 80% - answer-how many percent does aggregates represent in the concrete volume
Abram's Law - answer-"the compressive strength of concrete is inversely proportional to the
ratio of water to cement"
Accelerator - answer-SPEEDS UP the setting of concrete to reduce the whole curing period or
for early removal of forms
Admixtures - answer-Chemicals or additives added during concrete mixing to enhance specific
properties of the fresh or hardened concrete, such as workability, durability, or early and final
strength.
Aggregates - answer-- Any of various hard, inert, mineral materials, such as sand and gravel,
added to cement or mortar.
- should be HARD, dimensionally stable and free of clay, silt, and organic matter
Air-Entraining Agent - answer-- can be interground during manufacturing of Type I,II and III
cement.
- Enables the concrete to be highly resistant against CORROSION.
Bonding Agent - answer-to improve the bond between old and new concrete.
Cement - answer-a CALCINED mixture of CLAY and LIMESTONE, finely pulverized and used
as an ingredient in concrete and mortar.
Coarse Aggregates - answer-Types of Aggregates consisting of crushed STONE, GRAVEL, or
blast-furnace slag having particles larger than the ¼ in. (6.4mm)
, Coloring Agent - answer-are PIGMENTS or dyes mixed into topping to render/alter color evenly
to concrete surface
Concrete - answer-- an artificial, stone-like building material made by mixing CEMENT and
various MINERAL AGGREGATE with sufficient WATER to cause the cement to set and bind the
entire mass.
- the universal material of construction
- does not rot or burn
Creep - answer-long duration STRESS produces stress over time and consequently causes
permanent deformation.
Curing Process - answer-maintaining the HUMIDITY and temperature of FRESHLY PLACED
concrete during some definite period following, placing, casting or finishing to assure
satisfactory HYDRATION of cementitious materials and proper HARDENING of concrete.
Dispersal Agents - answer-prevents bleeding of concrete from concrete
drying shrinkage - answer-- as excess WATER EVAPORATES from the concrete, the concrete
SHRINKS slightly
- a reduction in the volume of concrete, mortar, or plaster caused by LOSS OF MOISTURE.
Fine Aggregates - answer-Types of Aggregates consisting of SAND having a particle size
smaller than ¼ in. (6.4mm)
Fine Aggregates & Coarse Aggregates - answer-Types of Aggregates
Frenchman J. L. Lambot - answer-who built several reinforced concrete BOATS in Paris in
1854?
Gas Forming Agent - answer-develops the potential STRENGTH of a concrete
Grout - answer-Other Uses of Cement:
cement + sand + considerable amount of water = __________
Hardener - answer-chemical/fine metallic aggregate improve the DENSITY of concrete surface
subject to impact and wear
Hardness - answer-a property of the surface which is related to durability as well as to
appearance
**A slab can be troweled or floated to draw more paste to the surface, but the harder superficial
layer has a tendency to spall
Heat of Hydration - answer-During the hydration process, considerable heat, called __________
___ __________, is given off
Hydration - answer-- Occurs during curing
- In which, the cement combines chemically with water to form STRONG CRYSTALS that
BINDS the aggregates together.