Managing the Heat Release of Calcium Sulfoaluminate Cement by Modifying the Ye’elimite Content

Abstract

Nowadays, calcium sulfoaluminate cement (CSA) is garnering a large amount of attention worldwide and is being promoted as a sustainable alternative to Portland cement for specific applications. This study aimed to control the heat release of CSA cement paste by choosing the appropriate composition. For this purpose, different calcium sulfoaluminate clinkers with up to 75 wt. % of ye’elimite were synthetized. Then, a reactivity study on the synthesized clinkers was conducted while varying the amount of gypsum added. The heat of hydration was measured by isothermal calorimetry. The influence of the ye’elimite content on the heat release and on the compressive strength was investigated. According to the findings, the amount of ye’elimite in the cement has a direct relationship with the heat release. The heat release as well as the mechanical performance increase with the increase in the ye’elimite content in the CSA cement. An equation allowing the prediction of the total heat release after 24 h is provided. Such data can be of particular interest to consultants aiming at the reduction of thermal cracking in massive concrete.

A Review on Chemical and Autogenous Shrinkage of Cementitious Systems

“…The volume of hydrated products of cement paste is smaller than the volume of the reactants (i.e., cement and water). This phenomenon is referred to as chemical shrinkage, hardening shrinkage or Le Chatelier shrinkage [16][17][18][19]23]. Le Chatelier measured the reduction in cement paste volume by means of a simple dilatometer using a glass beaker attached to a tube filled with water.…”

“…As reported by the Japan Concrete Institute (JCI), AGS is the macroscopic volume reduction in cement during early hydration at the initial setting time [19]. Nevertheless, other authors considered autogenous shrinkage as the measured disfiguration of cement paste in a locked system [31,32].…”

“…This is mainly due to the heat of the hydration degree of C 3 S and C 3 A. Later, the volume reduction in hydration products generated by the chemical reaction of cement composition with water and the consumption of water by the internal pores is referred to as chemical shrinkage [17,19,76]. Generally, the hydration of C 3 A is faster than that of C 2 S, C 3 S, and C 4 AF [77].…”

“…It takes place during the hydration of cement, whereas the total hydrate volume created is less than that of its reactants. CS is usually considered as the main driving mechanism, which contributes to early age cracking and durability loss of cement-based materials [18,19]. During the early stages of hydrations and before hardening takes place, the AGS and CS are approximately equal [14,[20][21][22].…”