Title: Dynamic Properties of High Strength Rubberized Concrete

Author(s): Ayman Moustafa and Mohamed A. ElGawady

Publication: Symposium Paper

Volume: 314

Issue:

Appears on pages(s): 1-22

Keywords: Damping ratio; fracture energy; high strength concrete; microstructure; rubberized concrete; scrap tires

DOI: 10.14359/51689741

Date: 3/1/2017

Abstract:
Green construction has been a very important aspect in the concrete production field in the last decade. One of the most problematic waste materials is scrap tires. The use of scrap tires in civil engineering is increasing. This article investigates the dynamic properties of concrete with replacement of fine aggregate with scrap tire. Two different rubberized concrete mixtures were designed. The first set; variable slump (VS) was designed to keep the mix proportions constant with rubber replacement as the only variable. The other set; constant slump (CS) was designed to keep the workability the same using superplasticizer. The compressive strength of the concrete was reduced by the use of rubber. The viscous damping ratio was investigated using free vibration tests with impact hammer on simply supported beams and drop weight tests. The replacement of up to 20% of sand with rubber resulted in an increase in damping with the increase being more in the CS beams as well. Beyond 20%, the effect on damping was insignificant. The average hysteresis damping was found to increase with the increase of rubber content. The fracture energy was found to increase with the increase of rubber content up to 20%. Microstructure investigation was also performed on the two mixes. It is concluded that the choice of the rubber content and the mixing process can have a significant effect on the dynamic properties of rubberized concrete. Recommendations for these two aspects were provided.