Study On Bending Toughness And Shrinkage Of Crumb Rubber Concrete

Crumb Rubber Concrete (CRC) is a new type of concrete mixed with rubber crumbs. CRC shows the characteristics of low Young's Modulus, large deformation, high energy dissipation and great crack resistance, because of mixing with rubber.In this paper, four groups of 12 short CRC beam are conducted bending toughness test. The strain-energy which is the energy absorption measurement of the material. The result shows that the bending strength significantly reduces when the rubber is mixed in the concrete. However, the ability of energy absorption increases significantly.In this paper, a novel method is used to evaluate the percent of drying shrinkage of CRC for the first time. Uneven moisture loss will lead to uneven drying shrinkage of concrete. The percent of drying shrinkage is evaluated by measuring the warpage which is result from uneven drying shrinkage. The characteristic of the shrinkage of both the ordinary concrete and CRC which are in the same water cement ratio and water consumption is studied, based on the six groups of 12 test picecs'(1300mm×100mm×50mm)measurement of the warpage. And the ordinary concrete and CRC which are in the approximate same strength are also studied. The study shows that the shrinkage of the CRC is more than the ordinary concrete, no matter what the strength relationship between the CRC and the ordinary concrete is.In this paper, the CRC composite beam is studied by the method which evaluates the warpage of the structure for the first time. The composite beam which are made up of the ordinary concrete and CRC is studied, base on the four groups of 8 composite beams'(2000mm×160mm×80mm) measurement of the warpage. Two types of concrete are in the same water cement ratio and water consumption. And the composite beam which is made up of two types of concrete in the same strength is also studied. Using the result of the study above, the shrinkage of the composite plan is studied by ANSYS. The study shows that the DCRC structure which is made up of approximately same strengh concretes has the better engineering application characteristic.