Variation of Ultrasonic Pulse Velocity of multiple-blended binders concretes incorporating thermally Activated Alum Sludge Ash

Abstract

In this paper the variation of Ultrasonic Pulse Velocity (UPV) measurements with the compressive strength of multiple blended binders concretes at the age of 3, 7, 28, 56, and 90 days are evaluated. The binders consist of Ordinary Portland Cement (OPC), thermally Activated Alum Sludge Ash (AASA) obtained from the thermal activation of alum sludge in an electrical furnace until 800°C for 2 h, and the pozzolanic materials, such as Silica Fume (SF), Ground Granulated Blast Furnace Slag (GGBFS) and palm oil fuel ash (POFA), for binary and ternary blends of OPC. The water to binder ratio and total binder content are maintained at 0.3 and 493 kg/m3 for all mixes.The results indicate the relationship between compressive strength and UPV was an extremely positive exponential for multiple-blended binders concretes. A determination coefficient of correlation (R2) of 0.889, which that indicates the presence of good exponential correlation between UPV and compressive strength for all types of concrete mixes. However, constants were different for each pozzolanic material and each level of OPC in concrete.