STABILIZATION OF A HEAVY CLAY USING LIME - POZZOLAN TRASS ADMIXTUR

• Main Author: Tjahyati, Hermin
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/2699
• Institution: Institut Teknologi Bandung

This thesis describes a study of the use of lime and pozzolan trass and lime-pozzolan trass combinations in the improvement of a heavy clay soil known as Ujung Berung clay. The type of pozzolan used in this study was from Nagreg (East of Bandung). The materials investigated were characterized by means of Atterberg limits, the standard compaction test and the unconfined compressive strength test. Material investigated included natural soil, natural soil plus 15 percent (by weight of dry soil) of admixture in which the proportions of lime and pozzolan trass were varied and soil plus lime alone. The experimental results indicate that the addition of pozzolan trass alone to the Ujung Berung clay has no immediate effect upon plasticity, compaction characteristics or strength. There is however a gain in strength when the mixture is allowed to cure. The effect of curing period on plasticity was not investigated. Plasticity is reduced as lime is substituted for pozzolan trass in the admixture. The reduction becomes greater as the proportion of lime in the admixture is increased. Substitution of lime for pozzolan in the admixture results in a reduction in dry density and an increase in optimum moisture content. The compaction characteristics of soil containing a certain amount of lime are different to those of the soil containing the same percentage of lime in combination with pozzolan. The addition of lime-pozzolan admixture produces an immediate gain in strength, the gain being greater as the proportion of lime is increased and as the material is allowed to cure. Soil containing a certain percentage of lime alone has considerably higher strength than the soil containing the same percentage of lime in combination with pozzolan . The effect of allowing the material to soak for a portion of the curing time is to reduce strength. Material containing pozzolan trass alone or only small percentages of lime cannot withstand the effect of soaking during the initial stages of curing. The results of the investigation suggest that the use of pozzolan in combination with lime would have a detrimental effect