Evaluation of the Effects of Untreated and Treated Sugarcane Bagasse Fibers and RHA on the Physicomechanical Characteristics of Cementitious Composites

The utilization of agricultural residues from mills or plants, such as sugarcane bagasse (SB) and rice husk ash (RHA), may contribute to the sustainability of civil engineering and the agriculture industry. In the present paper, the effect of SB fiber treatment and RHA inclusion on the flow, physical, and mechanical properties of cement mortars was investigated. Cementitious mortar mixes were prepared using 0%, 3%, and 6% untreated, heat-treated, and NaOH-treated SB fibers, and the most appropriate treatment method was chosen accordingly. Then, RHA was incorporated as 10% replacement for cement. The test results indicated that using heat-treated SB fibers was beneficial, with improved mechanical and physical properties without compromising fluidity compared to other materials. As compared to reference mortar, the incorporation of 3% untreated, heat-treated, and NaOH-treated fibers increased the compressive strength by 9.6%, 14.1%, and 9.3%, and flexural strength by 18.8%, 23.6%, and 12.1%, respectively. In addition, the 10% RHA substitution increased the compressive strength of mortar mixes by 41.2%, whereas similar flexural strength value was obtained. The combined use of RHA and 3% heat-treated fiber resulted in the highest flexural strength of 7.13 MPa, while the highest compressive strength of 38 MPa was obtained in the mixes produced with 10% RHA without SB fiber. The results of this study demonstrate the viability of manufacturing SB fiber-reinforced cementitious composites with competitive properties and their effective use in the construction sector, which can contribute to environmental sustainability.