Apa Precast Concrete Batch Plant Operator Exam With Complete Solution

APA PRECAST CONCRETE BATCH PLANT
OPERATOR EXAM WITH COMPLETE SOLUTION
Concrete is a mixture of _____, ______, and ______. ~CORRECT
ANSWER~cement, water, and aggregates.



The most commonly used concrete for structural purposes is: ~CORRECT
ANSWER~Normal weight concrete.



Normal weight concrete weighs approximately: ~CORRECT ANSWER~140
lb/ft^3



Lightweight structural concrete may weigh from _____ to ______ lb/ft^3.
~CORRECT ANSWER~90, 100



Heavyweight concrete may weigh ______. ~CORRECT ANSWER~200
lb/ft^3 or more.



Most concrete today is made with: ~CORRECT ANSWER~Portland
Cement



Concrete is usually referred to as a mixture of two components; ______ and
_______. ~CORRECT ANSWER~aggregate, paste

, The hardening process of the paste is a chemical reaction called _________.
~CORRECT ANSWER~Hydration



_______ is developed in the hydration process. It may peak up to _______
degrees. ~CORRECT ANSWER~heat;130 F



Concrete does hardens and cures by drying. True or False ~CORRECT
ANSWER~False ; Concrete does not harden or cure by drying, because
cement needs moisture to hydrate and gain strength. When concrete dries
fully, hydration stops, and it no longer gains strength.



A mixture of cement and water is called: ~CORRECT ANSWER~paste



When sand is added to paste it is called: ~CORRECT ANSWER~mortar or
grout



When coarse aggregate is added to mortar, the combination is called
______. ~CORRECT ANSWER~concrete



________ make up about 60 to 75% of the volume of concrete ~CORRECT
ANSWER~Aggregates