Role of Wollastonite Micro-Fiber in Rigid Pavement

Rigid pavements are the future of highways. Not only these act as an alternative for depleting bitumen made flexible pavements, but also provide high servicability and better performance under adverse traffic and environmental conditions. Under traffic load, the rigid pavement bends under flexure, necessitating its higer flexural strength.

Simple concrete is not ideal for rigid pavement because of poor flexural behavior and more shrinkage cracks. Under repeated traffic loading fatigue causes these small cracks to transform into bigger cracks, finally causing failure of pavement. Hence there is a need to increase the flexural strength of concrete mix, not by increasing the cement content, but by introducing such material which replace cement, reduce shrinkage and at the same time increase the flexural strength of concrete. Wollastonite micro- fiber, found as a ready to use material, is anticipated to perform likewise because of its fiber action along with pozzolanic properties. This study finds out its impact on shrinkage and flexural strength of self compacting concrete. It is found that the fleural strength of mix remains same for a cement replacement of about 32.5% whereas shrinkage resistance nearly increased 40% with its use.