Petrographical analysis of calcium aluminate cement mortars - Scanning electron microscopy and transmitted light microscopy

The samples studied for this paper were obtained from experimentally induce d carbonation and alkaline hydrolysis of calcium aluminate cement (CAC) mor tars. The mineralogical composition of phases present was studied from X-ra y diffraction (XRD) spectra. Scanning electron microscopy (SEM) and transmi tted light microscopy (TLM) were used to obtain some morphological (size an d shape) and fabric data of mineralogical phases to improve the interpretat ion of damage processes. SEM is a useful tool to examine the evolution of m ineral phases in cavities and discontinuity zones, The interpretation of th e degree of carbonation and the distribution of carbonated phases in the sa mples, the presence of C(3)AH(6) and CAH(10), as well as possible alteratio ns of aggregates are well differentiated and defined using TLM method, The main objective of the present paper is to validate the use of both microsco pic techniques (TLM and SEM) for the study of phase evolution in the CAC mo rtar during curing and degenerative processes. (C) 2000 Elsevier Science Lt d. All rights reserved.