Density and Water Absorption Coefficient of Sandcrete Blocks Produced with Waste Paper ash as Partial Replacement of Cement.

The literature is flooded with scientific information on most durability properties except water absorption coefficient of masonry units like sandcrete blocks. Also, while waste papers disposal is a systemic problem due to ineffectiveness of waste management system in developing countries, the price of cement is on the increase. This situation, ultimately, causes a bane in achievement of low-cost housing development considering the fact that sandcrete blocks are predominantly used as walling elements for such undertakings. In this study, solid core sandcrete blocks were produced with waste paper ash (WPA) utilized as partial replacement of cement at 5 % and 10 % volumetric levels. Chemically, the WPA was found to show similarity with cement in terms of SiO₂, Al₂O₃, and CaO contents. Density and water absorption coefficient of the block samples were determined. While density ranged from 1682 to 1872 kg/m³, water absorption coefficient varied from 27.04 to 23.49 kg/m²h^0.5. Statistically, no significant difference was revealed at p < 0.05 between experimentally-measured water absorption coefficients and those obtained using the model developed for prediction based on density of the samples. Thus, utilization of WPA as described herein could help to reduce the cost of procuring cement and in turn, enhance low-cost building construction. Also, with the developed model (showing dependence of water absorption coefficient on density), durability of sandcrete blocks exposed to moisture –prone environment could be easily predicted. [ABSTRACT FROM AUTHOR]