Concrete Exam Study Material - Practice Exam Solutions

Concrete Exam Study Material - Practice Exam Solutions a heavy pourable construction material made from a paste and aggregates is known as what? - answer - concrete ready-to-mix concrete amounts for about what amount of all concrete? - answer - 3/4 what concrete type is the most common? - answer - precast what type of concrete is normally used for smaller projects? - answer - prepacked a dry powder that forms a paste when mixed with water and glues the aggregates together when it cures is known as what? - answer - binder binders are commonly from what cement? - answer - portland the most expensive ingredient in the concrete mix is what? - answer - binder aggregates are known as creating what part of the conrete? - answer - the skeleton 60-80% of concrete volume is what? - answer - aggregates a chemical reaction happens when water is added to a binder called? - answer - hydration in hydration: - answer - the binder compounds form chemical bonds with water moleculeds for proportions of ingredients things to be considered are? - answer - workability, strength, durability, appearance, and economy reinforced concrete improves what kind of stregnth? - answer - tensile threaded steel bars and welded wire fabric bars are known as what? - answer - steel concrete reinforcement fiber reinforcement is mixed with what? - answer - tiny fibers fiber reinforcement increases concrete what? - answer - durability fiber reinforcement is used on? - answer - agriculture buildings, driveways, sidewalks, and roads a concrete spreader is also known as a? - answer - placer or leveler a tool used to place the concrete as close to finish level as possible is called what? - answer - concrete spreader instead of a concrete spreader what kind of shovel do you use? - answer - square end a concrete screed is also known as what? - answer - a straight edge or strike off a tool used to level off freshly placed concrete is known as what? - answer - a concrete screed what can be subsituted as a concrete screed? - answer - a straight 2x4 what kind of tool pushes the coarse aggregate below the concrete surface? - answer - concrete tamper a concrete tamper is also known as what? - answer - jitterbug what tool is used to level ridges and fill voids? - answer - bull float and darby bull float is used when? - answer - areas too big for darby a bull float produces what? - answer - a wavy surface what tool is used to level and smooth areas, so they match the rest of the concrete? - answer - hand float what tool is used to produce a smooth, hard, and dense surface after concretes been floated? - answer - concrete trowel what kind of blade does a trowel have? - answer - thinner a concrete edger reduces what? - answer - chipping when should the concrete edger be used? - answer - after bleed water water in concrete mix rises to the top and disappears is also known as what? - answer - bleed water what is the groove on the surface of the concrete called? - answer - control joint what kind of tool controls the location of cracks when the concrete shrinks? - answer - concrete groover a prepared surface where concrete is laid is known as the? - answer - subgrade the subgrade is critical to prevent what? - answer - cracking and sinking a subgrade should be? - answer - well drained, uniform, appropriately compacted, correct slope, free of organic matter how much fill material is needed for a subgrade? - answer - 4-6 inches soil should be compacted when it is freshly exposed why? - answer - it is at optimum moisture level compacting soil after it is exposed removes pores that? - answer - absorb water a heavy tamper is used with? - answer - small projects a vibrating compacter is used with? - answer - large projects hollow spaces and cavities left in concrete result from what effect? - answer - honeycomb an area of exposed fine aggregate caused from heavy water bleeding or mortar loss is known as what? - answer - sand streaking what is a c