PROPERTIES OF LOW GRADE BAUXITE SOIL AND BINTAN MINE TAILINGS AND WHEN MIXED WITH SURALAYA POWER STATION PULVERISED FUEL ASH

• Main Author: Joko Susilo, Sutarso
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/2821
• Institution: Institut Teknologi Bandung

PROPERTIES OF LOW GRADE BAUXITE SOIL AND BINTAN MINE TAILINGS AND WHEN MIXED WITH SURALAYA POWER STATION PULVERISED FUEL ASH, Sutarso Joko Susilo, 1993, Program Sistem dan Teknik Jalan Raya, Program Pendidikan Magister, Program Pascasarjana, Institut Teknologi Bandung. In many tropical countries, laterites and lateritic soils are commonly found. Laboratory and field studies in tropical countries have shown that lime - PFA (Pulverised Fuel Ash) mixtures can be successfully used for road construction. However, there is little work that has been carried out on the properties of bauxitic soil on its own or mixed with PFA. This thesis describes a study of the natural properties of Bintan Mine Tailings (BMT), a waste product of bauxite mining operations, Low Grade Bauxite (LGB) soil from Bintan island, and PFA from Suralaya power station, the end product of burning of Bukit Asam coal. It also describes an experimental study of the properties of PFA-LGB mixtures and PFA-BMT mixtures in various combinations. PFA is a non-plastic material, in this case containing about 74 percent of silt particles. LGB has a wide range of particle sizes, but has some poor properties. It is low in sand and silt fractions, its plasticity characteristic are sensitive to drying, and the coarse fraction has a great potential to breakdown when compacted. LGB belongs to the clayey gravel (GC) grouping in USCS and to the group of A-2-7 in the AASHTO soil classificitation system. BMT is non-plastic and a stable material, and is classified as a well graded silty sand (SM) in USCS, and as a A-1-b group material in the AASHTO soil classification system. Generally, the addition of PFA, in the order of 10-15 percent for LGB and 5-15 percent for BMT, signicantly improved the CBR strength, resulting from decreasing the pore size, improving particle interlocking, and reducing sensitivity to water. For LGB soil the addition of PFA can be expected to reduce the plasticity and reduced the particle breakdown effect due to compaction. As with the PFA-BMT mixes, improvements in CBR strength were also recorded, although not quite so significantly