CPII Material Testing 3

Question 1

What does the term 'water-cement ratio' directly influence in concrete mix design?

Accepted Answer

Strength and durability

Answer

The water-cement ratio is the primary factor controlling concrete strength and durability — lower ratios produce stronger, more durable concrete.

Question 2

When performing a sieve analysis on fine aggregate, which sieve size defines the boundary between fine and coarse aggregate?

Accepted Answer

No. 4 (4.75 mm)

Answer

The No. 4 (4.75 mm) sieve is the standard dividing line between fine aggregate (passing) and coarse aggregate (retained).

Question 3

A field density test using the sand cone method yields a wet density of 126 pcf and a field moisture of 8.5%. What is the dry density?

Accepted Answer

116.1 pcf

Answer

Dry density = wet density / (1 + moisture fraction) = 126 / 1.085 ≈ 116.1 pcf.

Question 4

What ASTM standard covers sampling freshly mixed concrete?

Accepted Answer

ASTM C 172

Answer

ASTM C 172 is the standard practice for sampling freshly mixed concrete from a truck or batch plant discharge.

Question 5

Which test determines the soundness of aggregate when exposed to freeze-thaw or wetting-and-drying cycles?

Accepted Answer

Sodium or magnesium sulfate soundness test

Answer

The sodium or magnesium sulfate soundness test simulates the deterioration effects of freeze-thaw cycles on aggregate by cycling immersion and oven drying.

(CPII) Certified Public Infrastructure Inspector Practice Test

(CPII) Certified Public Infrastructure Inspector Practice Test

CPII Material Testing 3