An Experimental Investigation on the Durability of Rice Husk Ash and Zirconium Oxide Nanoparticles Used in Mortar as Partial Replacement Material

This paper investigates the influence of using nano-zirconia and RHA used as a partial replacement of cement and sand in mortar, respectively. In the investigation, the water absorption percentage, ultrasonic pulse velocity, the effect on mortar after heating at various temperatures, SEM, were recorded. The use of sand in construction is increasing day by day. So, this is necessary to find a better alternative to sand. When RHA is burnt at a controlled temperature of 600 °C, the RHA shows similar properties to sand (Selvaranjan et al. in Development of sustainable mortar using waste rice husk ash from rice mill plant: Physical and thermal properties, 2021). The specific gravity of RHA is similar to the sand. Zirconium oxide is the powder form of zirconium metal. It has a high melting point. The zirconia was added in different percentages (1–5%) in the mortar and RHA was added as a replacement for sand (10–50%). All specimens are in the ratio of 1:3 (cement: sand). The optimum value of both the new materials added was found by checking their compressive strength. Both optimum values were combined in one mortar and then found new mortar that is 3% of zirconia and 50% RHA was added. The results reveal that the water absorption percentage is decreasing when zirconia is added and when RHA is added the water absorption percentage is less but increases gradually as compared to the normal mortar. The compressive strength is high at 3% zirconia mortar, i.e. 36.26 MPa and 50% CBRHA mortar, i.e. 30.76 MPa at 28 days. The ultrasonic pulse velocity test results reveal that after adding zirconia and RHA, and it improves the quality of mortar. The highest ultrasonic pulse velocity is recorded at 3% ZrO2 and 50% RHA, i.e. 4.6 km/s and 6.28 km/s, respectively, at 28 days. The maximum temperature combined mortar can bear is recorded as 400 °C and after heating the weight loss percentage is 18%.