Effect of adding rice husk on the physical and mechanical properties of concrete paving blocks

ABSTRACT

The research objective was to evaluate the physical and mechanical properties of paving blocks after incorporating raw rice husks into their composition. The proportions of 0%, 5%, 10%, 15% and 20% rice husk in relation to the dry mass of the cement were adopted. After curing, the pavers were subjected to visual inspection, dimensional evaluation, water absorption, compressive strength and density. The blocks produced with 20% showed high fragility. For the other pavers with rice husk, changes in the pieces were observed through the appearance of empty spaces and flaws on the edges of the blocks. Incorporating the rice husk did not modify the dimensional response of the blocks, with Shape Index values compatible with those in force in the standard. Considering the treatments with adding rice husk, the best performance for water absorption, compressive strength, and density was verified by incorporating 5% rice husk in the pieces. It is suggested to expand studies to improve physical and chemical treatments of rice husk in nature to better understand its properties and use as reinforcement in cementitious compounds.

Keywords
Natural fibers; Agro-industrial waste; Sustainable construction