Influence of Chitin Nanofiber and Rice Husk Ash on Properties and Bearing Resistance of Soft Clay Soils


1 Department of Civil Engineering, Roudehen branch, Islamic Azad University, Roudehen, Iran

2 Faculty of Civil Engineering, Shahid Rajaee Teacher Training University, Tehran, Iran

3 Faculty of Civil Engineering, KNT University, Tehran, Iran


Use of soft clay soils in construction activities has faced many problems. Some improvement, stabilization, and reinforcement methods is required to use these soils in body of roads, sub-foundations and embankments. In this research, the effect of chitin nanofiber and rice husk ash as additives on the behavioral properties and bearing resistance of soft clay soils by considering the processing time of 7, 28, 42 and 90 days was investigated. The suitability of chitin nanofiber to be used as an additive was evaluated by FTIR, XRD and SEM analysis. Different percentages of additives (1, 2, 4, 6 and 8%) with variations in chitin nanofiber and rice husk ash ratio were added to soil containing 6% lime. Maximum reduction on liquid limit and plastic index was obtained by addition of 2% additives to the soil containing 6% lime in which the percentage of chitin nanofiber was more than rice husk ash. Using examined additives in clay soil resulted in to a significant increase in bearing resistance, specifically at higher percentages of additives and curing times (days). As a whole, obtained results confirmed the potential use of chitin nanofiber and rice husk ash as additives for the improvement of soft clay soils.