Laboratory Evaluation of Performance of Pavement Quality Concrete Specimens Prepared Using Hybrid Fibers

In recent years, Indian highways have been constructed as rigid pavements as these pavements have high life cycle value when compared to flexible pavements. Pavement quality concrete (PQC) is used as the top surface layer in rigid pavement construction. The shrinkage cracks are formed during the hardening of PQC. These cracks allow mud, water and debris, resulting in mud pumping and other distress. The tensile cracks are formed in concrete pavements when the traffic load is applied exceeds the flexural strength of PQC. These cracks cause durability problems in the CC pavements. The microfibers are used in PQC to arrest the tensile cracks during the hardening stage of PQC, and macro (structural) fibers are used to enhance the flexural performance of PQC. In the past few years, hybrid fibers have been added to concrete to enhance the synergy. When two or more types of fibers are added to concrete to enhance its properties, these fibers are called hybrid fibers. In the present study, to avoid tensile crack formation during the fresh state of concrete and to improve the mechanical properties of PQC mix, both micro and macrofibers are added to concrete to obtain the PQC mix. It is concluded that the flexural properties of concrete composite improved at the optimum dosages.