Investigating the waterproofing properties of concrete made with rice husk ash and corn cob ash

The construction industry constantly strives to enhance the durability and water resistance of concrete structures, particularly in regions with varied climatic conditions like Nigeria. Traditional waterproofing methods often depend on expensive and non-sustainable materials, highlighting the need for more eco-friendly and cost-effective alternatives. This project investigates the potential of Rice Husk Ash (RHA) and Corn Cob Ash (CCA) as sustainable additives to improve the waterproofing properties of concrete. A comprehensive literature review underscores the importance of waterproofing in construction and the promising properties of RHA and CCA. RHA, derived from rice husk, exhibits pozzolanic characteristics that enhance concrete durability. Meanwhile, CCA, produced from corn cobs, helps reduce concrete porosity and improve moisture resistance. The experimental procedures involved collecting and preparing RHA and CCA and then incorporating these additives into concrete mixtures in varying proportions. All specimens were prepared using a mix ratio of 1:2:4 (cement: fine aggregate: coarse aggregate) and a water-cement ratio of 0.6. Slump tests and water absorption tests were conducted to evaluate the workability and moisture resistance of the concrete mixtures. Slump test results indicated a slight reduction in workability with higher proportions of RHA, though all specimens maintained acceptable slump values. Water absorption test results showed that concrete specimens containing RHA and CCA had significantly lower water retention compared to the control group. Notably, the mixture with 40% RHA and 60% CCA exhibited exceptional moisture resistance, showing no water retention after 28 days of curing. The findings suggest that a 40% RHA - 60% CCA mixture is the most suitable proportion for enhancing the waterproofing properties of concrete without significantly compromising workability. This study concludes that RHA and CCA are viable, sustainable alternatives for waterproofing concrete, offering benefits such as reduced material costs, environmental sustainability, and improved concrete performance. Further research is recommended to optimize these proportions and validate their effectiveness in real-world construction applications. This project contributes to sustainable construction practices by utilizing locally sourced agricultural waste products, thereby promoting environmental conservation and economic efficiency in the construction industry.