Ageing effect on swell, shrinkage and flexural strength of sand and waste marble powder stabilized expansive soil

Expansive soils in semi-arid climates must be mitigated to minimize potential structural damage to the overlying structures due to swell-shrink behavior caused by climatic changes. The expansive soil in this study was amended by sand which reduced the swell-shrink potential significantly. As a secondary additive, a waste by product of construction industry was selected, marble powder. Recycling this material would minimize its accumulation and covering a large space in landfill areas. In this study, waste material was assessed as a possible partial replacement for sand and due to its high calcite content, curing effect on its cementitious characteristic was also evaluated. It was observed that for mitigating the swell-shrink potential, 10% marble powder by dry mass was the optimum amount which was observed to gain improved characteristics with curing. The flexural strength, however, slightly reduced with marble powder addition, the soil mixture displayed a brittle behavior. Therefore the utilization of this material is recommended to be restricted to soils exposed to lower flexural loads, such as light traffic. The correlation between shrinkage strains and flexural strength parameters suggested herein, could be a potential empirical approach to predict the flexural strength based on shrinkage behavior.