Crack behaviour of mortar prism containing POFA as partially sand replacement using Acoustic Emission technique / Nurul Syahirah Noor Razali

Issues on preservation of natural river sand from being used excessively in construction industry has led to the efforts of utilizing palm oil fuel ash (POFA), a byproduct from palm oil industry as partial sand replacement in production of mortar. Thus, this study investigates the strength of mortar containing POFA as partially sand replacement at 5% compared with plain mortar. As the common investigation on strength of mortar contain POFA by using compression test and flexural test give lack of data on crack behavior, a new characteristic of mortar contain POFA under 3-point loading using Acoustic Emission (AE) technique was utilized. The crack behavior of mortar prism was monitored by AE technique and AE signals were collected. AE characteristics of mortar specimen with 5% POFA as partially sand replacement and plain mortar were studied. The behavior of the mortar specimen was analysed by AE energy and AE cumulative energy. Outcome of this study shows that strength of 5% POFA contain in mortar was reduced compared to plain mortar. The AE cumulative energy of 5% POFA contain in mortar is higher compared to plain mortar. Thus, 5% POFA contain in mortar also give more brittle material than plain mortar. However, it was noted that there was strong connection and correlation between visual observation of crack behavior and AE signal strength. Significant of the finding was POFA as partially sand replacement in mortar can be apply for construction of infrastructure such as rigid pavement and drainage system. Meanwhile, using AE technique provide an early prediction on structural performance ensuring safety for public used.