Characterization for Long-Aged Hardened Cement Collected from Old Structures by Modern Technique for Chemical Analysis

Abstract

Chemical analysis of cementitious material used in old structures yields empirical information concerning the long term-durability of concrete. Chemical analysis is also useful for scientific research on historical structures as a cultural heritage. Since the materials used in old structures have peculiarities deriving from the long time elapsed since the construction of the structures, it is necessary to take them into consideration for analysis. In this paper, guidelines for carrying out a systematic and effective analysis of old hardened cement even for small samples are proposed. Based on these guidelines, evaluation of a material such as hardened cement collected from actual old structures by X-ray fluorescent analysis, analysis of the acid-soluble part, powder X-ray diffraction and electron probe microanalysis were carried out, and the usefulness of the information obtained by these analyses is discussed.