Coupled effect of waste tire rubber and steel fibers on the mechanical properties of concrete

Studies in the literature indicate that while tire crumb rubber can be added to concrete to replace some natural aggregates, steel fibers need to be introduced to overcome the compromise in the mechanical properties of concrete, especially compressive and tensile strength, that would be caused due to the addition of tire crumb rubber exclusively. In the present study, a minimum content of steel fibers has been added to mitigate the negative impact of addition of tire rubber fibers on the mechanical properties of concrete. The tire rubber fibers content was varied from 1% to 3% by volume whereas steel fibers were added from 0.1% to 0.3% by volume only. In this way, the effectiveness of hybridized concrete using tire rubber and steel fibers was evaluated based on its mechanical properties. The results revealed that inclusion of steel fibers overcame the reduction in strength and toughness of concrete to which tire rubber fibers have been added. Concrete with 2% tire rubber fibers and 0.2% steel fibers showed better mechanical performance in terms of compressive strength (10%), split tensile (14.7%), flexural strength (6.6%), and flexural toughness indices ( T150D=46% T_{150}^D = 46\% , f150D=45% f_{150}^D = 45\% ) as compared to the concrete with only 3% tire rubber fibers.