The Partial Replacement of Ordinary Portland Cement with Rice Husk Ash to Stabilize Compressed Earth Blocks for Affordable Building Materials

The study investigated potentials of rice husk ash as a replacement for Ordinary Portland Cement in the production of Compressed Earth Block (CEB) with a view to reducing building construction cost and the embodied energy of the blocks in the context of Nigeria. Graded levels (i.e. 10, 20, 30 and 40%) of RHA replaced cement in the mix for CEB moulding. The results of X-ray diffraction showed that RHA contained 80% SiO2. Also, the results of the compressive strength, water absorption capacity, and bulk density testing indicated that low compressive strength, high water absorption capacity, and low bulk density exhibited by RHA-CEB make doubtful the suitability of RHA as a partial replacement for Ordinary Portland cement in the building construction in the wet regions. However, RHA could find useful application as a stabilizing agent in CEB rather than as a partial replacement of cement.