Micro- and Pore Structure Analysis of Volcanic Ash Blended Cement Paste

Volcanic ash blended cement based concrete are known for its better performance in terms of strength and durability, especially in marine environments where hot and cold climatic conditions along with chloride and sulphate attacks are detrimental for the construction materials. Since the properties of volcanic ash will vary with region to region, complete knowledge of chemical composition and thorough understanding of the hydration mechanism is unavoidable to find out the optimum dosage of volcanic ash for better performance. Understanding the cement hydration process and characterizing the hydration products in microstructural level is a complex and interdependent process that allows one to design complex mix proportions to produce sustainable concrete materials. Here, the micro- and pore structure of cement paste samples prepared with locally available ordinary Portland cement (OPC) and regionally available volcanic ash (VA) was studied by using Isothermal Calorimetry, N2-Adsorption analysis, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The studies show that, even though the added VA reduces the initial cement hydration process, it could be used as a potential replacement of OPC up to a certain extent for the development of sustainable high performance concrete