Concrete

Question 1

Describe concrete

Answer 1

Concrete is a cementious material produced by a
chemical reaction of Portland cement and water to
which inert materials called aggregates such as
sand, gravel or crushed stone, are added

Question 2

Define aggregate

Answer 2

Aggregate -this material is mixed with cement
to make the concrete. Common aggregates are
both fine and coarse

Question 3

Define cast in place concrete

Answer 3

this concrete is molded in the location in which it is expected
to remain.

Question 4

Define Casting

Answer 4

the process of placing fluid concrete
into moulds, generally called forms, in which the
concrete is permitted to harden to a certain shape.

Question 5

Define Plain concrete

Answer 5

concrete

that has no reinforcement.

Question 6

Define pre tensioning and post tensioning

Answer 6

processes by which steel rods or tendons are
placed under tension drawing the anchors
together. The tensioned steel places the concrete
in COMPRESSION
(u tube video)

Question 7

Define pre caste concrete

Answer 7

this concrete has been cast at a

location other than the place where it is to remain.

Question 8

Define pre stressed concrete

Answer 8

pre-stressing places engineered
stresses in architectural and structural
concrete to offset the stresses which occur in
the concrete when it is placed under load.

Question 9

Define reinforced concrete

Answer 9

this is a composite material made of steel and concrete. Steel provides
the tensile strength that concrete lacks

Question 10

Define spalling in concrete

Answer 10

this term describes the loss of surface
material when concrete (or stone) is subjected to
heat. Some concrete and certain aggregates are
more subject to spalling than others