Influence of fine aggregate based on palm kernels on the hardened state and morphology of mortars

Abstract

This study utilized organic waste based on palm kernels in mortar production, aiming to reduce the consumption of fine aggregates. The effect of using aggregates based on comminuted palm kernels was verified. Both reference mortars based on expanded vermiculite and mortars with volume replacement by comminuted palm kernels at levels of 25% and 100% by volume were produced. Prismatic specimens were used for axial compressive strength testing, in addition to cementitious plates for measuring thermal conductivity. Microstructural characterization techniques were performed to understand the hardness, morphology, thermogravimetric behaviour, and mineralogical properties of the bio-based aggregate and expanded vermiculite. Regarding the microstructural analysis of cementitious matrices based on expanded vermiculite and bio-based aggregates, SEM and XRD techniques revealed the formation of the same elements and hydration products, as evidenced by similar micrographs and diffraction peaks. The most satisfactory results for the mortar were observed with contents of 25% (aggregates based on comminuted palm kernels), thus demonstrating its viability in both technical and environmental terms regarding sustainability.