RETRACTED: Water absorption control of ternary blended concrete with nano-SiO2 in presence of rice husk ash (Retracted article. See vol. 57, pg. 173, 2023)

In the current study, the effects of SiO2 nanoparticles as additive with two different sizes of 15 and 80 nm on water absorption of rice husk ash (RHA) blended concrete have been investigated. Concrete samples were prepared by replacing 10, 15 and 20 wt% of cement with RHA and 0.5, 1.0, 1.5 and 2.0% of cement with SiO2 nanoparticles followed by curing in lime solution for 7, 28 and 90 days. The results indicated that the resistance to water absorption of Portland cement-nano SiO2-rice husk ash (PC-NS-RHA) ternary blended concrete was considerably improved with respect to the control concrete. This improvement was observed at all curing ages and replacement levels but the optimal point was reached for 20% of RHA incorporating 2% of 80 nm SiO2 particles at 90 days of curing. Fast formation of C-S-H gel in the presence of ultra high active nano-sized SiO2 and micron level RHA particles together with their high filler effect may result in a continuous cement paste with the lowest weak zones. It has been concluded that the use of novel ternary blended concrete (PC-NS-RHA) provides significant reduction in the water absorption of concrete.