Experimental Investitation On Bond Properties Between CRC And Bars And Pilot Study On CRC Structures

Crumb Rubber Concrete (CRC) is a new kind of energy-saving and environmental-protection building material with crumb rubber as a constituent from discarded tires. It shows a characteristic of being high in ductility, energy absorption, crack resistance and ultimate compressive failure strain. In some application of concrete, the most commonly used concrete (plain concrete) does not always fulfill the requirements such as low unit weight, high toughness and impact resistance. As a result, Crumb Rubber Concrete which shows excellent performance meeting the requirements offers a promising material in civil engineering, especially in structural engineering. To ensure the safety of reinforced CRC structures in engineering application, bond behaviors between CRC and bars must be studied.Experimental study of bond behaviors between CRC and bars is carried out based on the pullout test of 80 speciments in this paper. The enfluence of amount of crumb rubber, compressive strength of concrete, diameter of deformed bars and plain bars on bond behaviors is discussed and compared to plain concrete. By the way of experimental statistical regression, the calculating formula of characteristic bond strength value and characteristic slip value is established. The bond failure process is also obtained and further discussed. The testing results show a higher ductility, equivalent bond strength compared to plain concrete and a lineal relationship between bond strength and compress strength of the concrete. Finally, the design of anchoring length has been proposed.Moreover, pilot study on structural application of CRC is carried out. Some bearing capacities, structural performances are analysed. And seismic performance of CRC shear wall is discussed. The results show that the flexural capacity of reinforced CRC beam and shear wall section is equivalent to those of plain concrete. But the seismic performance is better. Under the same conditions, the interstory shear forces will reduce to 30% compared to that of plain concrete reinforced shear wall.