STRENGTH CHARACTERISTICS OF EMC2 - STABILIZED SOIL

• Main Author: Arsil, Budi
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/2851
• Institution: Institut Teknologi Bandung

Compaction and strength tests on some tropical residual soils in Java were carried out. The soils were obtained from three locations, i.e. Cepu (East Java), Cikalong (Purwakarta, West Java) and Pasir Impun (Bandung, West Java) and were tested at various dilution ratios and curing times to observe the effect of a stabilizing agent EMC2 on the strength characteristics, as assessed in terms of Dynamic Cone Penetrometer (DCP) and Unconfined Compression Strength (UCS), over a range of compaction conditions. In the DCP test, DN (penetration rate in mm/blow) is the measure of relative strength. DCP and UCS tests were carried out on compacted samples of untreated and treated materials.The swelling of those samples soaked for 4 days prior to testing was measured. Recommended dilution ratio and 2 other dilution ratios, above and below the recommended value, were examined. The water content of treated samples was optimum moisture content obtained from the standard Proctor compaction procedure. It was found that the application of EMC2 had no influence on dry density values. A clear pattern did not emerge from this study of the influence of EMC2 on the swelling characteristics of the soils investigated. A significant reduction in swelling was found generally in the Cepu soil (from 1.69 % for untreated sample at optimum moisture content to swelling in the range 0.36 % to 1.42 %, with one extreme result of 2.11 % recorded). In the case of Cikalong and Pasir Impun soil, values of swelling recorded for EMC2 - treated material were above and below those of the untreated materials (respectively, from 0.35 % for the untreated samples of Cikalong soil at optimum moisture content to the range 0.16 % to 0.61 % for treated samples and from 0.31 % for untreated samples of Pasir Impun soil at optimum moisture content to the range 0.15 % to 0.45 % for treated samples). It was found that the effect of curing time on strength development in the DCP test was dependent on the soil type. The longer curing time did not always result in reduced DN value. The curing times that produced the lowest value of DN were 1 day for Cepu soil (penetration rate reduced from 18.4 mm/blow to 14.67 nun/blow) and 3 days for Cikalong and Purwakarta soil (penetration rate reduced, respectively, from 11.50 mm/blow to 9.53 mm/blow and from 16.98 mm/blow to 9.79 mm/blow). Water content was found to affect the strength characteristics of the untreated and treated samples. The penetration rate reduced as the water content increased up to optimum moisture content, and thereafter increased with increase in water content. The values of DN at the optimum moisture content for untreated samples were 18.4 , 11.50 and 16.98 mm/blow, for Cepu, Cikalong and Pasir Impun soils, respectively, and in the case of Cikalong soil, the values of DN at the wet-side of the DN-moisture content relationship were found to be sensitive to water content. The undrained shear strength of untreated samples increased as the water content increased up to optimum moisture content, and thereafter it decreased with increase in water content. The highest values of undrained shear strength at the optimum moisture content for untreated samples were 145.33, 230.4 and 396.23 a, respectively for Cepu, Cikalong and Pasir lnpun soils. The undrained shear strength values determined for the treated soils were generally lower when compared with the untreated samples. These results are likely due to sample disturbance that took place when following the procedure to obtain samples of treated material for the UCS test .