Concrete is one of the most durable materials used in True
modern construction, true or false?
What is concrete composed of? Portland cement, coarse and fine aggregate, and water
When water is added to concrete mix what state is Concrete in a plastic state
produced?
What is hydration? A chemical reaction between cement and water
What is essential to ensure concretes final strength and Quality control of concrete and its placement
appearance?
What is segregation? The separation of sand and cement ingredients from the coarse aggregate in a
concrete mix
When are concrete forms removed (stripped)? After the concrete has set and is hard enough to resist damage
Which concrete forms are removed using a crane? Large panel forms and ganged panel forms
What makes up the largest part of a concrete mixture? Fine and coarse aggregate
What is fine aggregate? Sand
What is coarse aggregate? gravel or crushed stone, ranging from sizes of 1/4" - 1 1/2" diameter
How is the size of coarse aggregate chosen for a concrete Chosen based on the spacing between the rebar placed, and the distance between
mixture? opposite form walls
What size coarse aggregate should be used generally? The maximum size permitted, should not be larger than one fifth the narrowest
dimension between form walls or not larger than three fourths the minimum distance
between rebar
What does cement act as? A paste that binds the aggregate when water is added
What is most cement derived from? Limestone
, Carpentry Level 1 - Concrete Test
What is "warehouse pack" When bagged Portland cement becomes lumpy while being stored. Corrected by
rolling the bags over to break up the lumps
What is compressive strength? The amount of force the concrete can withstand 28 days after it has been placed
What is the average period of time concrete needs to 28 days
reach its full strength?
How is compressive strength expressed? Pounds per square inch (psi) or Mega pascals (Mpa)
Water cement ratio (w/c) plays a major role in the True
compressive strength of concrete, true or false?
What does a low water cement ratio produce? Strong and dense mixtures
How is water cement ratio determined? Dividing the weight of water by the weight of the cement contained in a cubic yard.
What are some types of concrete mixtures? high early, air-entrained, lightweight, heavyweight, roller-compacted, decorative,
reinforced, and shotcrete
What is high early strength concrete? Concrete that uses type III Portland cement, that achieves a greater amount of
strength in a shorter amount of time than standard concrete mix.
What is lightweight concrete? A concrete that uses a lightweight aggregate like, vermiculite, perlite, pumice, shale,
clay, slate, slag, or cinders. Helping to reduce the overall weight of the concrete
mixture.
What compressive strength of concrete is considered 2500 psi and up
structural?
What are concrete mixtures with compressive strength less Used as fill concrete or insulating concrete
than 2500 psi used as?
What is heavyweight concrete, and what is it used for? A mixture that uses a heavy aggregate like magnetite or steel punchings. Used as a
shield to protect people from radiation
Describe pervious concrete? A mixture of Portland cement, coarse aggregate, and little to no sand. This leaves
voids in the concrete when it sets to allow water to penetrate through rather than
flow off. Used in parking lots, streets, and sidewalks.
What are three types of decorative concrete? Exposed aggregate concrete, Architectural concrete, and coloured concrete