EFFECT OF GROUND GRANULATED BLAST FURNACE SLAG ON STABILIZED EMBANKMENT SOILS UNDER TRIAXIAL LOADING

Abstract

Industrial waste materials like Ground Granulated Blast Furnace Slag (GGBS), Granulated Blast Furnace Slag(GBFS), which are by products of Iron and steel industry are increased day to day and have similar properties as that of cement. So utilizing these by-products for stabilization benefits both environmental and economic aspects. The main objective of the present study is to Utilization of GGBS for improving various engineering properties of the soil as an alternative to lime or cement. In this study, usage of GGBS with different proportions in sub grade was analysed under static and dynamic loads. Soil sample was collected from pond in NIT Trichy, Tamil Nadu, India. The Index and Engineering properties (Standard proctor compaction, Unconfined compression test, California bearing ratio test) of soil with and without GGBS was determined for different combinations of GGBS with soil and optimized at 16% based on strength performance tests. It is observed that the improved soil strength depends on the amount of GGBS. The work is further extended to know the variation in strength of soil with and without GGBS under dynamic loads by conducting cyclic triaxial tests. Dynamic properties of soil (i.e., Shear modulus and damping ratio) are found out using strain controlled unconfined cyclic triaxial tests carried out as per ASTM D3999 and results are presented accordingly. The effect of GGBS inclusion is evaluated as a function of shearing-strain amplitude, confining stress, cycle number and GGBS content. It was found that the effect of GGBS content is significant on both shear modulus and damping ratio particularly at high shear strain amplitude. Thus effect of fibres in the improvement of dynamic properties of pond sand is investigated and feasibility of GGBS for ground improvement is explored.