Experimental Study of a Cohesive Soil Modified by Polyacrylamide on Local Soils in West Java']Java, Indonesia

The geotechnical properties of Polyacrylamide (PAM) mixed with a type of local soil called silty soil are discussed in this study. First, five mixed variations of PAM (0.2%, 0.4%, 0.6%, 0.8%, and 1%) were tested in the laboratory to determine local soil properties. To examine the engineering properties of modified soil, curing time (1, 3, 7, and 14 days) has been carried out for the shear strength test. The mixture of PAM and soil was compacted to find engineering properties, such as unconfined, triaxial, consolidation, and California Bearing Ratio tests. In addition, this study improves mechanism analysis to review soil morphology due to PAM modification. The results indicated that the addition of PAM showed good performance in shear strength and was influenced by the curing time. PAM is proven to improve the parameters of bearing capacity and consolidation. The results from the analysis of particle content show that PAM mainly interacts with soil particles. That confirmed the pores space had been reduced by acrylamide bonds that can increase soil strength. In the bearing capacity, a dosage of 0.4% PAM is the minimum to fill up the requirements for backfill materials. The experimental data are expected to contribute to the application of base materials in road pavement construction.