Civil Insight: A Technical Magazine Volume 3 | Page 15

Civil Insight (2019) 15-20 Civil Insight: A Technical Magazine Strength of Red Soil Treated with Cement at Different Ratios 1,* Suman Manandhar, 2 Sanjeev Singh Karki 1 Visiting Faculty, Department of Civil Engineering, Kathmandu University, Nepal, [email protected] Student, M.Sc. in Engineering Geology, Central Department of Geology, Tribhuvan University, Nepal, [email protected] 2 Abstract The soil-cement (S/C) mixing is one of the most common and economic techniques in the world to receive the strength of soil quickly. In this reference, research has been carried out in red clay for the foundation of solar grid panel using cement at Battar Bazar in Trishuli area. The red soil represents fines (silt and clay) and sands with occasionally coarser soils. To increase the strength of soil, red soil from Ratmate area was blended together in different proportions and maximum dry density was measured. Then, Portland Pozollana Cement (PPC) of Standard Type-I was mixed at different proportions and Unconfined Compression Strength (UCS) test of the sample was done in the laboratory. In this research, Ratmate (ML) was mixed with cement contents of 3, 5, 7, and 10% and cured for 7, 14, and 28 days in air and in water for the determination of the optimum mechanical strength. The result showed that 7% of cement is quite enough to receive the optimum strength when cured for 28 days. Keywords: Red soil, Soil-cement (S/C) ratio, Unconfined Compressive Strength (UCS) 1) Introduction The improvement of ground by using cement is widely practiced in several countries as it is easy to use and economic when compared to other methodologies. However, this technique is very limited in engineering projects and researches in context to Nepal. Several pioneer geotechnical researchers such as Terashi et al. (1979, 1980), Kawasaki et al. (1981), Kamon and Bergado (1992), and Horpibulsuk et al. (2006) have investigated the mechanical behaviors of cement ad-mixed clays. Proceeding, Rawasa et al. (2005) also carried out the investigation in expansive clay by using lime and cement at specific temperatures using cement. The result showed appearance of cementious bond between calcium silicate and aluminate hydration products with soil particles. Lee et al. (2005) had worked on Singapore Clay and compared with Bangkok Clay and Boston Blue Clay and determined that the cement mix significantly improves the unconfined compressive strength (UCS) as well as the shear strength of soil. More than 80% settlement of the foundation had reduced and increased UCS values when treated with cement (Farouk and Shahien, 2013). On the other hand, Manandhar et al. (2014) also traced the important findings that the strength had increased after receiving good dry density near to its optimum moisture content. This research has been confined to improve the mechanical behaviour of red soil for the construction of foundation for the solar grid panel installation at Battar Bazaar in Trishuli. To receive the good mechanical strength, meaning the maximum unconfined compressive strength, the red soil from Ratmate area was mixed and treated with cement in different proportions of 3, 5, 7, and 10% and cured for 7, 14, and 28 days. *Corresponding Author Email address: [email protected] (Suman Manandhar) Submitted on October 12, 2019; Accepted on December 7, 2019 15