Application of Fiber-Reinforced Rubcrete for Crash Barriers

Abstract

Concrete crash barriers are structures provided to channel the road traffic and prevent catastrophic accidents resulting in loss of life. The failure of concrete crash barriers is often due to vehicular impact. Improved impact resistance is essential to increase the service life of concrete crash barriers. Studies have shown that the use of crumb rubber in concrete enhances the impact resistance and toughness of concrete. The addition of fibers assist in improving the toughness resistance of concrete and play a vital role in controlling the cracks. Experimental and numerical studies were carried out to ascertain the impact strength of fiber-reinforced rubcrete crash barrier’s. This paper presents the results of impact tests conducted on M 40 grade concrete, fiber-reinforced concrete, and fiber-reinforced rubcrete crash barrier models. Impact tests carried out on rubcrete, steel fiber-reinforced concrete, and polypropylene fiber-reinforced concrete prisms have led to economic proportions of crumb rubber, steel fibers, and polypropylene fibers for higher energy absorption capacity. The results show that the most economic proportion for crumb rubber that can replace fine aggregates by volume was found to be 15%. For obtaining the minimum cost to energy absorption ratio for steel fiber-reinforced concrete and polypropylene fiber-reinforced concrete, 0.75% and 0.2% of the total volume of concrete should be placed with steel fibers and polypropylene fibers, respectively. Energy absorption studies carried out on the one-third scaled-down model of crash barriers revealed that steel fiber-reinforced rubcrete crash barriers exhibited three folds energy absorption capacity in comparison to the concrete crash barrier. Numerical studies on the finite element models of crash barriers have shown similar trends as obtained in the experimental investigations with respect to energy absorption characteristics of crash barriers.