Strength and microstructure properties of double layered concrete paving blocks containing waste tyre rubber granules

Abstract

This paper aims to examine the effect of replacing the natural aggregate with waste tyrerubber granules. Waste tyrerubber granules were used as aggretate replacement in the pavingblock at four different percentage: 10%, 20%, 30%, and 40%. The paving blocks were tested in terms of their strength and the characteristics of their microstructure by measuring compressive strength, flexural strength, splitting tensile strength, and skid resistance. Field scanning electron microscopy (FESEM) and Fourier Transform Infra- Red(FTIR) analysis werecarried out on the paving block specimen. When 10% of the natural aggregate was replaced with waste tyrerubber granules, there was no substantial difference in the compressive strength but the flexural and splitting tensile strength increased to a certain extent. When more than 20% of waste tyrerubber granulesis incorporated in the paving blocks, the strength is acutely reduced even though there is a growth in ductility. The results proved that even after failure, the paving blocks did not shatter but still stayed imperforated. Double layer rubberized concrete paving blocks (DL-RCPBs) are more flexible and soft to the surface, and thus provide a better ride quality. This characteristic makes it suitable for trafficked roads. DL-RCPBs (30% and 40%) with low strength characteristics could be used on roads that not required high strength and may be viable for other applications, depending on the percentage of waste tyre rubber used. DL-RCPB with higher waste tyre rubber content exhibit higher skid resistance especially on dry surface but reduced on slippery surface. Two main factors that influence the skid resistance are high elasticity and rough surface texture of waste tyre rubber. It is suggested that DL-RCPBs could be introduced as one of alternative concrete paving block (CPB) that can be used in paving application.