Predicting the Compressive Strength of Obudu Earth Blocks Stabilized with Cement Kiln Dust
The study investigates the effect of Cement Kiln Dust (CKD) on the Compressive Strength of Obudu Earth Blocks. The soil used for the blocks was classified as A -7-6 (0) or CH. CKD content of up to 20% by weight of the dry soil was used to evaluate the Compressive strength of the blocks at 12%, 16% and ,20% water content by dry weight of the CKD-Soil matrix. 150 mm x 150 mm stabilized cubes moulded at various CKD and water content were cured and crushed at 7, 14, and 28 days. The study found that the compressive strength of CKD-soil block was about twice and half higher than that of the unstabilized block, and exceeded the minimum strength of 2.0 N/mm2 recommended by “ASTMD1633-00” or 2.8 N/mm2 of “BS 6073”. The Compressive strength of the earth blocks generally increased with increase in CKD content and curing period. The curing condition was also found to affect the strength of CKD-earth blocks, and 35% reduction in strength was observed with direct sun light curing. Scheffe’s optimization models were used to predict the compressive strengths of the CKD-soil blocks at varying proportions of CKD. It was concluded that CKD can be used as a good stabilizing agent for the Obudu earth blocks.