The Impact Of Rubber Particle Size On The Mechanical Properties Of Roller Compacted Rubberized Concrete (RCR)

RCC(roller compacted concrete) is a new type of concrete that developed in the last 10 years, it has many advantages such as the high speed of construction,large area of operation,high strength,strong durability, and so on.It has been widely used in lathlike structures and thin plate structures, such as dams, highway pavements, seepage control faceplates, and so on .However, as a large volume of concrete, the application and promotion in projects of RCC are limited due to its, poor performance on crack resistance and deformability. Rubberized concrete has been paid great concerned in recent years as a new type of concrete .Incorporation of rubber can reduce the mechanical strengths of rubberized concrete,but the toughness ,deformability and shock resistance can be enhanced significantly. Thus the study to improve the toughness and deformability of RCC by adding a portion of rubber particles has great significance.The paper is a part of the subject, named Properties of Roller Compacted Concrete (No.50679054), which is financial supported by the National Natural Science Foundation of China. Experiment is the main way to study the paper.In this study ,the changes of properties for the RCC were investigated in terms of both size and amount of the rubber chips.All specimens prepared by replacing portion of sand in RCC with the same volume of rubber particles and moist-cured for 28 days at 20oC and 98% relative humidity.Based on the test results, the following conclusions may be drawn:1,The rubber particle size has not obvious impact to the workability of RCC, but it has shown a worse trend with the decrease of rubber particle size.2,With the increase of rubber content, the mechanical strengths of RCC reduced obviously ,such as compressive strength, splitting tensile strength, axial compressive strength, flexural strength, flexural modulus of elasticity and static compressive elastic modulus ; but some other performances were inhanced,such as bend pressure ratio,axial compression ration and ultimate tensile deformation.The result shown that the incorporation of rubber can reduce the mechanical strengths of RCC, but the deformability can be enhanced.3,With the same rubber content, when the rubber particle size decreases, the mechanical strengths of RCC reduce obviously ,such as compressive strength, splitting tensile strength, axial compressive strength, flexural strength, flexural modulus of elasticity and static compressive elastic modulus .The result shown that the RCC incorporated smaller rubber particle size has the worse mechanical properties.4,With the same rubber content, when the rubber particle size decreases, the bend pressure ratio,axial compression ration and ultimate tensile deformation of RCC increased; on the same compressive stress, the compressive strain also increased. The toughness,deformability and shock resistance of RCR were inhanced with the decrease of the rubber particle size.