Characterization of Mortar from Church Ruins in Barangay Budiao, Daraga, Albay

¹ School of Chemical, Biological, Materials Engineering and Sciences, Mapúa University, Muralla St., Manila, Philippines, 1002
² College of Social Sciences and Philosophy, Bulacan State University, Malolos, Bulacan, Philippines, 3000

Abstract

The lack of information about the correct ways of restoring historical masonry materials from cultural heritage structures tends to create more damage to the said structures. According to Cesare Brandi’s theory of restoration, existing historical materials must be replaced with their equivalent. This paper presents the chemical composition of historical mortars acquired from church ruins of barangay Budiao, Daraga, Albay, Philippines. The historical mortar sample was characterized using petrographic analysis, sieve analysis, atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA), and infrared spectroscopy (IR). Petrographic analysis shows that the mortar sample is bounded by 90% organic material particularly coral and is held together by microcrystalline calcite (micrite) matrix that comprises of 10% of the total sample mortar composition. Sieve analysis shows a well-graded particle distribution. Atomic absorption spectroscopy (AAS) was also utilized to determine the %Ca for each sieve fraction using HCl for acid digestion. TGA thermograph shows the non-linear drop in weight between 740°C and 850°C, which corresponds to the degradation temperature of calcium carbonate or limestone. IR analysis shows essential characteristic peaks of CaCO₃ at 712 cm^-1, 874 cm^-1, and 1437 cm^-1.