Geotechnical Properties of Problem Clay Stabilized with Crumb Rubber Powder

Mangalore tiles are a type of tiles native to the city of Mangalore, India. These are widely used as a roofing material throughout India, especially in coastal regions to drain off the rain water. But in recent times the tile industries have been facing problems due to non availability of good clay. The available clay for the manufacture of tile is lacking in desirable properties. The properties of the available clay have to be improved by some methods. It is proposed to use Crumb Rubber Powder (CRP) which is made from scrap and old tires is used as an additive to improve problem clay and study the effect of CRP on strength of problem clay after stabilization. The main objective of the investigation is to evaluate optimum CRP for stabilization of the clay from the view point of plasticity and strength characteristics. This paper reports the findings of experimental studies with regard to geotechnical properties (particle size, specific gravity, compaction characteristics, and unconfined compression strength (UCS) of both problem clay and stabilized clay, and to evaluate their suitability in tile industry. Also an investigation was carried out to study the effect of cement and lime on CRP stabilized clay. The investigation revealed that CRP altered the engineering properties of problem clay and 5% CRP has been chosen as the optimum CRP to get desired properties. The unconfined compressive strength was increased when the optimum mix (problem clay+5% of CRP) was blended with cement and lime.