Operator 2025/2026 Exam Questions and
Answers | A+ Score Assured
Concrete is a mixture of _____, ______, and ______. - 🧠 ANSWER
✔✔cement, water, and aggregates.
The most commonly used concrete for structural purposes is: - 🧠 ANSWER
✔✔Normal weight concrete.
Normal weight concrete weighs approximately: - 🧠 ANSWER ✔✔140 lb/ft^3
Lightweight structural concrete may weigh from _____ to ______ lb/ft^3. - 🧠
ANSWER ✔✔90, 100
Heavyweight concrete may weigh ______. - 🧠 ANSWER ✔✔200 lb/ft^3 or
more.
, Most concrete today is made with: - 🧠 ANSWER ✔✔Portland Cement
Concrete is usually referred to as a mixture of two components; ______
and _______. - 🧠 ANSWER ✔✔aggregate, paste
The hardening process of the paste is a chemical reaction called
_________. - 🧠 ANSWER ✔✔Hydration
_______ is developed in the hydration process. It may peak up to _______
degrees. - 🧠 ANSWER ✔✔heat;130 F
Concrete does hardens and cures by drying. True or False - 🧠 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: - 🧠 ANSWER ✔✔paste
When sand is added to paste it is called: - 🧠 ANSWER ✔✔mortar or grout
When coarse aggregate is added to mortar, the combination is called
______. - 🧠 ANSWER ✔✔concrete
________ make up about 60 to 75% of the volume of concrete - 🧠
ANSWER ✔✔Aggregates