Performance of Fiber-Reinforced Rubcrete Curbs Subjected to Impact Loads

Abstract

A curb is a barrier or a raised boundary provided to demarcate between the roadway and footpath or median. Curbs have a high probability of being subjected to impact loads due to collision from vehicles. The frequency of repairs in curbs can be reduced by using a material with enhanced impact resistance. Rubcrete (concrete in which fine and coarse aggregates are partially or fully replaced with tire rubber) serves as a potential material to improve the impact resistance of concrete. But the strength parameters of the material are reduced when crumb rubber is replaced with aggregates. Steel and polypropylene fibers can be added to rubcrete to enhance the energy-absorption capacity of rubcrete and to improve the strength parameters. Drop weight impact tests were carried out on disks to determine the optimum proportion of crumb rubber in rubcrete, steel fibers in steel fiber–reinforced concrete, and polypropylene fibers in polypropylene fiber–reinforced concrete. The optimum percentage of crumb rubber, steel fibers, and polypropylene fibers was fixed based on the energy absorption to cost ratio. Drop weight impact tests were carried out on reinforced concrete beams to validate the numerical model developed. This paper presents the numerical investigations carried out on the impact behavior of curbs made of ordinary concrete, fiber-reinforced concrete, and fiber-reinforced rubcrete. The results of the numerical study on curbs indicate that the impact resistance of steel fiber–reinforced curbs exhibited an improvement of 172% when compared to the impact resistance of concrete curbs.