Settlement Analysis of Recycled Concrete Fine Aggregate Blended Soils using Geostudio

Abstract

Crushed concrete (CC) is one of the most abundant waste materials generated from construction industry. This material is widely recycled and used in various applications like pavement, concrete aggregates and backfilling. Crushed concrete is mixed with any of virgin soil to increase the engineering properties of soil. In the present study, a sample of crushed concrete is collected from demolished buildings at Secunderabad and the material is segregated according to gradation for the present study. The index properties of crushed concrete like pH, specific gravity, water absorption, particle size distribution are obtained. Locally available soil is partially replaced i.e., 30%, 50%, and 70% with crushed concrete fine aggregates and its compaction characteristics and shear strength parameters are determined. In the continuation of the study, a numerical model is developed using a finite element software i.e GeoStudio Sigma/w. Mesh and boundary extent convergence studies are done for the model. The top 1m virgin soil is replaced with the mixture of CC and soils. Settlements for various percentages of CC and for different width of footing are obtained for a uniform stress of 200kPa. The stress is applied in 5 stages in order to simulate real field conditions. It was observed that 30% replacement of CC have given the least settlement for all widths of footing considered in the study