Title: Impact Resistance and Acoustic Absorption Capacity of Self-Consolidating Rubberized Concrete

Author(s): Mohamed K. Ismail and Assem A. A. Hassan

Publication: Materials Journal

Volume: 113

Issue: 6

Appears on pages(s): 725-736

Keywords: acoustic emission technique; crumb rubber; drop-weight impacts; impact resistance; metakaolin; self-consolidating concrete

DOI: 10.14359/51689359

Date: 11/1/2016

Abstract:
An experimental study was conducted to investigate the effect of using crumb rubber (CR) on improving the impact resistance and acoustic insulation of self-consolidating concrete mixtures. The study particularly aimed to maximize the percentage of CR in self-consolidating rubberized concrete (SCRC) to develop mixtures with high potential use in applications involving high-impact resistance, energy dissipation, and acoustic absorption. Several parameters were investigated—namely, percentage of CR (0 to 50% by volume of sand), type of supplementary cementitious materials (SCMs) (fly ash, slag, and metakaolin), binder content (500 to 550 kg/m3 [31.215 to 34.335 lb/ft3]), coarse aggregate size (10 to 20 mm [0.39 to 0.79 in.]), and entrained air. Tests included fresh properties, compressive strength, impact loading (drop weight on cylindrical specimens and flexural impact loading on small scale beams), ultrasonic pulse velocity, and acoustic emission measurements. The results indicated that it is possible to develop SCRC mixtures with optimum percentages of CR, which give promising results for concrete having higher energy absorption, acoustic insulation, and reduced self-weight compared to conventional concrete. The impact energy required to initiate the first visible crack and/or ultimate failure crack of the tested cylindrical specimens increased up to a CR replacement of 30%, while the impact energy required to break the tested beams increased up to a CR replacement of 20%. On the other hand, the acoustic absorption capacity of the tested mixtures continued to increase as the CR increased.