ACI ASTM C138 Latest Version with Complete Solutions

ACI ASTM C138 Latest Version with Complete Solutions ASTM C138 is used for what test method for Density(unit weight), Yield, and Air Content(gravimetric) of concrete A lower density may indicate what 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 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 lightweight and heavyweight A change in density could affect the what pumpability, placeability, finishability, and strength of all types of concrete. Yield is defined as what the volume of concrete produced from a mixture of known quantities of the component materials. A= air content(percentage of voids) in the concrete C= actual cement content, (lb/yd3) Cb= mass of cement in the batch, (lb) D= density(unit weight) of concrete, (lb/ft3) M= total mass of all materials batched, (lb) Mc= mass of the measure filled with concrete, (lb) Mm= mass of the measure Ry= relative yeild T= theoretical density of the concrete computed on an airfree basis, (lb/ft3) Y= yield, volume of concrete produced per batch, (yd3) Yd= volume of concrete which the batch was designed to produce, (yd3) Yf= volume of concrete produced per batch, (ft3) V= total absolute volume of the