Pozzolanic reaction of sugarcane bagasse ash and its role in controlling alkali silica reaction

Abstract

Pozzolanic materials are used worldwide to improve concrete properties. In this study, the pozzolanic behavior of sugarcane bagasse ash (SBA) and its role in controlling alkali silica reaction (ASR) was investigated. For this purpose, SBA was acquired from a sugar processing industry. Locally available reactive aggregates were used to introduce the phenomenon of ASR. To evaluate the role of SBA in mitigating ASR, mortar bar specimens were prepared following ASTM C1260 with various SBA dosages (10%, 20%, 30% and 40% by cement weight). To investigate the pozzolanic behavior of SBA strength activity index test and thermal analysis were performed. Results of activity index and thermal analysis showed the pozzolanic behavior of SBA. Moreover, reduction in mortar bar expansion was observed 23% and 46% after replacing 10% and 40% cement with SBA, respectively. Microscopic examination also showed no signs of cracks in mortar bars incorporating SBA; however minor cracking was observed in control specimens due to ASR. Furthermore, Energy disperse X-ray spectroscopy (EDS) showed low Ca/SiO2 ratio of mortar bars incorporating SBA due to dilution process and alkali absorption leading to control the ASR expansion. Therefore, based on the results it can be concluded that pozzolanic behavior of SBA can be helpful in controlling ASR expansion by binding alkalies.