Heat‐cured concrete: Improving the early strength and pore structure by activating aluminosilicate internal curing agent with triisopropanolamine

Abstract

Although heat‐cured concrete (HCC) has received extensive research interests in recent years, it still suffers from problems including coarsened microstructure, low cement hydration degrees, etc, which limited its application. Some of these problems can be solved by internal curing method resulting in low early strength of HCC and low‐production efficiency. This study addressed this issue by activating the aluminosilicate internal curing agent (lightweight fine aggregate, LWFA) with triisopropanolamine (TIPA). The results indicated that more Al3+ and Fe3+ ions were dissolved from LWFA by TIPA, which assisted the formation of hydrates with cement ions in interfacial transition zone (ITZ), and enhanced the density of ITZ in the early stage. The introduction of TIPA was found to increase the early compressive strength of HCC, by approximately 15.3%, 25.9% and 28.0%, respectively for the cement cured for 1, 3, and 7 days compared with control samples. Moreover, the results of rapid chloride migration and water absorption depth also suggested that coupling the aluminosilicate internal curing agent with TIPA improved the pore structure of HCC.

Improve the long-term property of heat-cured mortars blended with fly ash by internal curing

“…IC has currently emerged as a promising technology that can produce concrete with increased resistance to earlyage cracking and enhanced durability [32]. The primary objective of IC is to maximize hydration and minimize desiccation [32][33][34][35][36][37][38][39][40]. Subsequently, IC has been proved to reduce shrinkage and delay or eliminate unwanted cracking [41].…”

“…Expanded shale, forming from the calcination of shales, is one type of LWFA and of great interest to use in concrete manufacturing. Due to the synergistic effect of IC and pozzolanic reactivity, this kind of aggregate can promote cement hydration and strongly strengthen the interfacial transition zone (ITZ) [36][37][38][39][40]45,46].…”