Fundamental Mechanical Properties of Mortar Incorporating Rice Husk Ash as Pavement Material

In the quest for sustainable solutions to environmental challenges, the exploration of alternative materials derived from by-products has gained considerable momentum. In the engineering industry, rice husk ash (RHA) stands out as a promising candidate to replace cement. It is an amorphous powder rich in silica that possesses pozzolanic properties similar to ordinary cement. Therefore, using RHA in concrete not only promises a means of waste management, but it also can potentially increase the performance of concrete. This study investigated the mechanical properties of specimens of mortar incorporating RHA as a partial replacement for cement. To properly assess the suitability of RHA for use in pavement, the hardness and slip resistance of specimens were also tested. The results showed that the particle size and loss on ignition of the RHA significantly influences the workability of mortar incorporating RHA. Some of the hardened specimens could achieve higher strength than the control specimen. However, increasing the RHA content from 10 to 20% led to a significant decrease in the strength and slip resistance of the specimens. Nevertheless, all RHA types used in the study developed sufficient flexural strength, satisfactory slip resistance and excellent hardness values, which makes them potentially safe and comfortable, both as road and pedestrian pavements. Finally, our analysis of the CO2 emissions during production demonstrated that the use of RHA is less damaging to the environment than is cement.