Sonic testing of steel reinforced concrete

Abstract

The effect that water-cement ratio, cement-aggregate ratio, reinforcing steel, and the aggregate type have on pulse-velocity measurements in concrete is studied. Twenty-on concrete mix designs were developed and used to vary these parameters in plain concrete beams and cylinders and in reinforced beam specimens. A combination of sonic pulse-velocity testing and compressive strength testing was conducted for all mix designs as well as for six field core specimens removed from the deck of a bridge in service. An attempt to correlate laboratory specimen results with field specimen results is made with the ultimate goal of being able to predict the in-situ concrete properties of ultimate compressive strength and static modulus of elasticity by the use of pulse-velocity measurements. Results indicate that ultimate compressive strength and static modulus of elasticity as well as water-cement ratio, cement-aggregate ratio, aggregate type, weight density percentage of reinforcement, and to a lesser extent, the proximity of reinforcement appear to be related to pulse velocity. A correlation between "through" and "along" pulse-velocity measurement techniques is made, as well as a correlation between beam velocity measurements and cylinder velocity measurements. A relationship between dynamic and "initial tangent" static modulus of elasticity is made.