文档介绍：parative Study of the Reactivity of Calcium Silicates during Hydration and Carbonation Reactions Warda Ashraf 1 , Jan Olek 1 *and Vahit Atakan 2 School of Civil Engineering, Purdue University, West Lafayette, IN 47907, USA 2 .Director, Research and Development, Solidia Technologies, NJ, USA Abstract This work presents pa rative study of the hyd ration and carb onation reactions of three calcium silicate phases . Triclinic tricalcium silicate and γ-dicalcium silicate we re synthesized in laboratory from stoichiometric mixture sof CaO and fumed silica (SiO 2). The reactivity of the synthesized calcium silicate systems we re then monitored during both carbonation and hydration reaction s . Along with the synthesized calcium silicates, the reactivity of natural wollastonite was also investigated in this work. For carbonation reaction, calcium silicate samples were first mixed with deionized wat er and then exposed to CO 2 . After 24 hours of reaction the samples were analyzed using Fourier Transform Infrared (FTIR) Spectroscopy , thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM) techniques . The p resence of Ca(OH) 2, CaCO 3and calcium silica te hydrates (C - S -H) was identified in case ofboth hydrated and carbonated tricalcium silicate and dicalcium silicate specimens . For wollastonite specimen , polymerized silica and CaCO 3were identified as the main reaction products . In order t pare the reactivity of the calcium silicate systems ,the relative amount sof reaction products were also determined using TGA and FTIR test methods. The relative amounts of reaction products determined using these two methods were found to be i n very good agreement with each other. Using both of these test methods, higher amount of reaction products were found in case of carbonation reaction than in the case of hydration reaction. Originality Many publications can be found in the literature pare mechanical pr