Estimating the firing temperature of a brick sample from a church convento archway ruin in Quipayo, Camarines Sur, Philippines

The firing of bricks is one of the most critical manufacturing steps that affect its durability. It also directly reflects the past artisan’s skills and technological knowledge. This study estimates the firing temperature range of a brick material from a Spanish Colonial Period church convento archway ruin in Quipayo, Camarines Sur, Philippines. A combination of different analytical techniques, namely energy dispersive X-ray fluorescence (EDXRF), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray (SEM-EDX), and thermogravimetric analyzer (TGA), were utilized to determine the mineralogical and chemical composition. From the resulting composition data, the firing temperature of the brick material was estimated to be within the range of 900 to about 1,100 °C and burned in an oxidizing atmosphere. The information derived from this study provides a baseline chemical data of historical bricks that can help assess future conservation works.