Optimization of Banana Fiber Reinforced Fly Ash Based Geopolymer Mortar

Abstract

[email protected] past decades since Joseph Davidovits introduced geopolymer, this innovative green technology as alternative for cement mortar have been studied and proven its strength, effectiveness, and potential to many applications. Likewise, crack proneness due to lack of reinforcement, occurrence of efflorescence and curing methods are issues on geopolymer. This paper focused on the effects of treated banana fibres (BF) using 4 % sodium hydroxide (NaOH) soaked within 2, 4 and 6 h which served as reinforcement on the geopolymer mortar with different parameters to eliminate macro cracks and two curing methods were used to address efflorescence. Fiber reinforced geopolymer mortar (FRGM) can lessen the massive utilization of conventional construction materials due to sustainability of geopolymer and provide crack bridging in the matrix. Compressive and split tensile strength test of geopolymer cube and cylinder samples for burlap and saran wrapped method of ambient curing were determined using universal testing machine (UTM). The flowability, weight loss of samples during curing period and the occurrence of efflorescence were observed as well. In Design Mixture - 1 (DM1), there are 13-design mixtures (DM) with 5 - 50x50x50 mm cubes and 5 -100x200 mm cylinder specimens each reinforced with BF while 8 DMs for DM1 are plain geopolymer mortar (PGM) to obtain the mixture with the highest compressive and split tensile strength for both FRGM and PGM. FRGM and PGM with the highest mechanical strength are further explored reinforcing with treated and untreated BFs. Mechanical strengths, flowability, efflorescence and weight loss of samples were recorded. The optimum FRGM shows that there is no significant difference in compressive and split tensile strength when reinforced with 4 % NaOH treated within 2 and 6 h compared to 4 h of treatment which has the highest strengths. Finally, the governing BF with 4 % NAOH treated within 4 h was used to reinforce the PGM to investigate the strength variation provided by BFs which gave up to 22.43 % increment in terms of compressive strength.