Soil Improvement through the Utilization of Agricultural Residues from Nigeria

摘要

This work deals with soil stabilization using ash obtained from both open air and oven burning of the rice husk collected from Abakaliki Rice Mill in Ebonyi State of Nigeria. The soil samples were collected from the proposed borrow pit site at Onu-Ogba Nike near Enugu, Enugu State, Nigeria at depths of 0.5 - 1.5 m. The laboratory tests were conducted in accordance with (8, 9] at the Soil Mechanics Laboratory of Civil Engineering Department. Enugu State University of Science and Technology. Enugu, Nigeria. The soil samples were prepared for stabilization by weighing out ten equal samples from the natural soil and gradually adding to each sample progressively 0 %, 2.5 %, 5 %, 7.5 %, 10 %, 12.5 %, 15 %, and 17.5 % by weight of the rice husk ash. The results obtained indicate that 59 % of the natural soil samples passed the sieve No. 200 with average plasticity index and CUR values of 21 and 8 % respectively. Similarly, the result of the blended soil samples indicate that the plasticity index (PI) values decreased from 28 - 10.4 % while the corresponding California bearing ratio (CBR) values increased from 9.1 - 25 % alter which it started decreasing to 22 %. The result of this study suggests that Ihe stabilized soil sample with 15 % rice husk ash gave the highest CBR value of 25 % with a PI value of 10.4 % indicating its high potential for soil stabilization. The adoption of rice husk ash for soil stabilization would encourage the effective disposal and utilization of the abundant rice husk waste in most developing countries. It could also offer some employment opportunities to rural dwellers.