Study On The Influence Of Rubber Particles Quality To The Capability Of Rubber Concrete

The composition of the raw materials of the rubber particles is very complex, thus resulting into significant differences of the rubber particles in their chemical composition, additive composition, surface morphology and mechanical properties, etc. Therefore, scholars had, in their studies of the characteristics of rubberized concrete, come up with different opinions concerning the pattern of the changes in several properties of the rubberized concrete.This paper started by the discussion of the raw materials of the waste rubber particles and categorized them into tire rubber particles, inner tire rubber particles and miscellaneous rubber particles. These three kinds of rubber particles were used to make rubberized concrete and modified rubberized concrete, through the study of their compressive strength, the influence that the quality of rubber particles had on the rubber concrete compressive strength and the performance of the modifier was ascertained. Based on the test results, the rubber particles of better quality were chosen and used for the studies on the splitting tensile strength of the rubberized concrete and the compressive properties and impermeability of the modified rubberized concrete. The main contents and conclusions of the studies are as follows:(1) Tire rubber particles had the best quality in terms of improving compressive strength and the modification effect of the modifier. It was also found that the modification effect of rubber particles is related to the concentration or mass fraction of the modifier, whereas as the optimal concentration of modifier is related to the quality of rubber particles.(2) With the increment in dosage of rubber, the splitting tensile strength of rubber concrete showed a clear downward trend, while the tension and compression ratio showed an upward trend substantially. At the same dosage, with the increase in rubber particle size, the extent of the decline in splitting tensile strength of the rubber concrete compared with the ordinary concrete had been reduced. However, there are no clear patterns how the rubber particle size affected the tension and compression ratio of rubber concrete.(3) The splitting test method of transversally split cylinder can be used to determine tensile strength of not only common concrete, but also rubber concrete. When the comprehensive influence coefficient in rubber concrete is taken as 0.53, the calculation formula to determine tensile strength has higher precision.(4) There are respectively optimal values for the splitting tensile strength of the rubberized concrete and for the compressive properties, stress resistance property and impermeability of the modified rubberized concrete; however, the optimal values of these properties correspond respectively with different rubber particle sizes, the dosages and the modifiers. Therefore, it is impossible to make all the properties the modified rubberized concrete optimal by merely using a single processing method or a single mix design, and it is required, while in engineering practice, to achieve only single optimal performance or several optimal performances with other performance fulfill the basic engineering requirements.