Ultrasonic assessment of concrete strength at early ages

Abstract

Synopsis This paper describes tests carried out to examine the relationship between ultrasonic pulse velocity and cube strength of concrete from ages of about 3 h over a curing temperature range from 1 to 60°C. It is found that this relationship is practically independent of water/cement ratio and temperature but influenced by both aggregate content and type of cement. Strength estimation from pulse velocity was found to be less reliable for velocities less than about 2 km/s than it is for higher velocities. Prediction of 28 day cube strength from early-age pulse velocity is possible with some limitations, particularly with regard to temperature effects.