Portland cement/acrocomia aculeata endocarp bricks: Thermal insulation and mechanical properties

In the last few decades, Portland/residue composites have been researched due to their technological and environmental advantages. In this study, residues of Acrocomia aculeata (Jacq.) Lodd endocarp (AE) were introduced in the Portland cement-soil (PC) matrix in different concentrations (0, 5, 10, 15, 20, and 50 wt%) to produce PC/AE bricks. The characterization of the microstructures of the bricks indicate agglomerates of AE particles with increased humidity in small regions distributed throughout the matrix. Mid-infrared and laser-induced breakdown spectroscopy, along with thermogravimetry, indicated that AE contained mainly lignin and cellulose, as well as inorganic chemical elements such as Mg and Si. X-ray studies revealed that AE did not affect the crystallographic properties of the Portland/AE bricks. The findings indicate that the use of AE improved the thermal insulation capability of the composites with a small impact on the compressive strength.