INFLUENCE OF TRIISOPROPANOLAMINE ON THE HYDRATION REACTION OF MODERATE HEAT AND LOW HEAT PORTLAND CEMENTS MIXED WITH LIMESTONE POWDER

Abstract

In this study, the effect of triisopropanolamine （TIPA） on the strength development and hydration reaction of moderate-heat Portland cement （MC） or low-heat Portland cement （LC） with limestone powder （LSP） was investigated. Compressive strength of MC or LC slightly decreased at 7 days and significantly decreased at 28 days by addition of LSP. On the other hand, the compressive strength of MC or LC containing LSP increased by addition of TIPA at 28 days, however the compressive strength at 7days did not increase. There was a significant correlation between compressive strength and porosity of hardened cement paste with LSP regardless of the addition of TIPA. In addition, the reaction of alite （C₃S） and belite （C₂S） did not change by addition of TIPA. However, the reaction of ferrite （C₄AF） and CaCO₃ at early stage were significantly accelerated by adding of TIPA. And the formation of monocarbonate in MC-LSP or LC-LSP system was promoted by addition of TIPA.