Early strength development in cement-treated sand using low-carbon rapid-hardening cements

Abstract

Soil stabilization through cementation is a commonly-adopted ground improvement technique in which Ordinary Portland Cement (OPC) is widely used as the binding material. This paper explores the applicability of a low–carbon, rapid-hardening calcium sulfoaluminate (CSA) cement for an accelerated and sustainable soil treatment. This study extensively investigates the early strength development in cement-treated sand with two commercially available CSA cements, through the ultrasonic pulse velocity (UPV) test and the unconfined compressive strength test. UPV evolution curves for the first 24 h are obtained, and the effects of different cement contents and types on pulse velocity and compressive strength at early age are studied. The CSA cements used in this study contain ye’elimite as the main cementing phase with different amounts of calcium sulfate. It is shown that the presence of the calcium sulfates, or lack thereof, significantly influences the initial strength and stiffness gained by the CSA-treated sand. CSA with calcium sulfate develops higher strength in the first 12 h than CSA without calcium sulfate, whereas the 1-day strength is higher for CSA with more ye’elimite phase. The 1-day compressive strength of CSA-treated sand is 2–9 times higher than that of OPC-treated sand, depending upon the cement type and content.