IDENTIFICATION OF SOFT CLAY EXPANSIVITY WITH METHYLENE BLUE TEST AND THE EFFECT OF NANO SIZE PARTICLE OF RICE HUSK ASH (RHA) FOR EXPANSIVE SOIL IMPROVEMENT

• Main Author: Alif Wahyunindya, Taliessya
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68723
• Institution: Institut Teknologi Bandung

The presence of nanomaterials in soil is indicated by the presence of nano-sized minerals that form soil and rocks, such as montmorillonite with a size of 100-500 nm (Das, 2014). These nano-sized minerals react chemically at the nanoscale as well. Indonesia produces around 50 million tons of rice annually, with an average of 4 million tons of rice husk ash produced (Muntohar, 2002). With this amount generated,, there is a potential for the utilization of rice husk ash byproducts as a soil improvement material. The Methylene Blue test is a test to identify the soil expansiveness easily, quickly and relatively affordable, compared to the expansivity test using the swelling test and CBR. Methylene blue value (MBV) is linearly correlated with plasticity index and exponentially correlated with expansive mineral content, swelling potential and swelling pressure. This study used rice husk ash (RHA) and nano rice husk ash (Nano RHA) as soil stabilizers. The soil samples used for soil improvement were from Grobogan and Wonogiri, Central Java, with a very high level of expansivity. Soil improvement mixture using 5%, 10%, 15%, 20% and 25% of RHA with curing time 0, 3, 7, 14 and 21 days. Soil improvement mixed with 5% and 10% nano ASP based on the weight of the soil used in the test. Maximum dry density (MDD) parameter decreased along with the increase in RHA levels. RHA can increase soil strength based on UCS test and reduce expansivity based on index properties test, methylene blue test and swelling test. Based on these considerations, the use of RHA more than 10% is considered ineffective. The results of this test showed that the use of nanoparticles of rice husk ash increased soil compressive strength by 15-20% and was more effective in reducing expansiveness than rice husk ash with the same percentage.