ACI ASTM C138 questions well answers rated A+ 2024/2025

ACI ASTM C138ASTM C138 is used for what - correct answer test method for Density (unit weight), Yield, and Air Content(gravimetric) of concrete A lower density may indicate what - correct answer 1) materials have changed [lower specific gravity], 2) higher water content, 3) higher air content, 4) a change in proportions of ingredients, and/or 5) lower cement content. If a reduction of the density of the concrete was due to an increase in air content what can be expected - correct answer the concrete could be more durable in resistance to freezing and thawing, but the strength, abrasion resistance, resistance to chemical attack, shrinkage, and cracking qualities of the concrete will be affected. density test must be used on what type of concretes - correct answer lightweight and heavyweight A change in density could affect the what - correct answer pumpability, placeability, finishability, and strength of all types of concrete. Yield is defined as what - correct answer the volume of concrete produced from a mixture of known quantities of the component materials. A= - correct answer air content(percentage of voids) in the concrete C= - correct answer actual cement content, (lb/yd3) Cb= - correct answer mass of cement in the batch, (lb) D= - correct answer density(unit weight) of concrete, (lb/ft3)