HYDRATION OF CALCIUM SULFOALUMINATE CEMENT IN PRESENCE OF ZINC CHLORIDE
The structural flexibility of the two mains hydrates, ettringite and calciummonosulfoaluminate hydrate, produced by calcium sulfoaluminate cements (CSA cements)hydration may give rise to chemical entrapment of some heart metals salts, such as ZnCl2.The properties of mortars made with CSA cement (mechanical strength and lengthchanges) and their hydration process were thus investigated (by calorimetric and XRDmeasurements) as a function of various parameters: the gypsum content of the CSA cement(from 0 to 35％), the composition of the mixing solution (either pure water, or a ZnCl2solution with a variable concentration ranging from 0 to 0.5 mol/L) and the thermal evolutionat early age, with a view to develop a cementitious material to stabilize Zn-rich waste. Increasing the gypsum content accelerates the hydration process but decreases the totalheat of hydration. The precipitation of ettringite is promoted and the porosity increased. Theinfluence of zinc chloride on hydration depends both on the zinc concentration in the mixingsolution and on the gypsum content. The thermal history of the cement-based material is alsoa key parameter since it modifies the rate of hydration, the mineralogy of the cement pasteand the macroscopic properties of mortar samples as mechanical strength.
S.Berger C.Cau Dit Coumes P.Le Bescop D.Damidot
CEA/DEN/MAR/DTCD/SPDE,BP 17171,30207 Bagnols/Ceze cedex,France CEA/DEN/SAC/DPC/SCCME,91192 Gif/Yvette,France Civil & Environmental Engineering Department - Ecole des Mines de Douai,764 BdLahure,59500 Douai,Fra
国际会议
南京
英文
67-76
2008-10-13（万方平台首次上网日期，不代表论文的发表时间）