Analysis of the infrared spectrum and microstructure of hardened cement paste

Phase transformation was found in hardened cement paste exposed to dynamic loading caused by typhoon and the normal static-dynamic loading. The concre te samples were obtained from a 20-year-old residential building. The bondi ng characteristics and microstructure of the hardened cement paste with dif ferent loading history have been carefully studied using scanning electron microscopy analysis and infrared spectrum technique. The scanning electron microscopy micrographs indicate that there is a morphological difference in the con crete microstructure. The infrared spectrum analysis has provided information for understanding the phase transformation characteristics of t he primary bonds and secondary bonds. This has led to the establishment of a microscopic model describing the correlation between the behavior of the hydrate lime and the properties of the hardened cement paste. (C) 1999 Else vier Science Ltd. All rights reserved.