Hydration Study of Calcium Sulfoaluminate-Based Formulations by Quantitative in-situ X-ray Diffraction
Calcium sulfoaluminate cements (CSA) have been known for several decades, but they have recently been considered as a promising low-CO2 alter native to Ordinary Portland cements and an opportunity for the wastes recy cling.Various applications of these binders have been developed, for instance low-shrinkage, self-stressing and high early strength cements, depending upon the composition and on the reactivity of the cement.However the relationships between these factors and mechanical properties have not been yet deeply studied in terms of mechanisms and kinetic of the hy dration process and microstructure and composition of the resulting hydrated phases.In this study, both the hydration kinetic and products of both binary and ternary mixtures composed by an industrial CSA clinker, an industrial Portland cement clinker and two different calcium sulphate sources were investi gated.In particular in this paper the progress of hydration of different cements has been observed by in-situ X-ray diffraction (XRD) with a climatic chamber, in which both the temperature and the humidity can be controlled and the hy dration at the younger ages of cement paste can be studied in-situ without stop ping hydration with solvents1,2.The quantitative results obtained by means of Rietveld analysis using an external standard method results were also correlated with heat flow curves3.The microstructural characteristics of the mixtures studied have been also correlated with the macrostructural characteristics of the related mortars, such as the compressive strengths.The results obtained in this study confirm that in-situ XRD could be a powerful tool for studying the hydra tion process of cementitious systems giving fundamental information for foresee ing the final technical performance of calcium sulfoaluminate-based formula tions.
Sulphoaluminate cement Quantitative X-ray diffraction
Marchi M. Scotti F. Allevi S.
CNR-Istituto per la Dinamica dei Processi Ambientali,Milano,20131,Italy CTG S.P.A-Italcementi Group,Bergamo,24121,Italy
国际会议
武汉
英文
99-111
2013-10-23（万方平台首次上网日期，不代表论文的发表时间）