Thermal insulation and mechanical characteristics of cement mortar reinforced with mineral wool and rice straw fibers

Building insulation is an essential requirement for buildings located in areas of varying temperature conditions. However, the conventional building insulation techniques accrue high cost and consume resources. This work aimed to evaluate the use of mineral wool and rice straw to improve Portland cement mortar's thermal insulating properties. Samples of 40x40x160 mm mortar were produced with cement and sand, but varying mineral wool and rice straw constituents from 0 to 50% in weight. Water absorption, flexural and compressive strengths , thermal conductivity were performed in samples with and without mineral wool and rice straw addition. The microstructure of mortars was analyzed using scanning electron microscopy (SEM). It was observed that reinforcing mortars with mineral wool and rice straw fibers yielded a significant drop in the mortar's thermal conductivity, improving their insulative abilities. Although the addition of fibers, in turn, deferred the mechanical performance in some mixes, however, it was not too significant or below workable standards. The performed tests prove the feasibility of adopting the selected fibers for insulating Portland cement mortars. • Mineral wool and rice straw as thermal insulation enhancer. • Thermal conductivity of mortar reduced with fiber additions. • Rice straw and mineral improved mechanical properties of mortars.