The Change And Mechanism Of Strength Of Rubber Concrete At High Temperature In Natural Environment

Rubber concrete contains rubber particles that are susceptible to high temperatures in the natural environment and affect its strength.However,this effect has not been systematically studied.Normal concrete mix ratio design method was adopted,and ordinary concrete,reference rubber concrete and NaOH solution modified and “NaOH+KH570” compound modified rubber concrete were respectively equipped,and an electric heating box was used to simulate the high temperature of the natural environment.The study was conducted at a relatively high temperature of 60°C.,80 °C and 120 °C,natural cooling and cooling,water cooling and cooling,"relative high temperature-natural cooling" cycle and "relative high temperature-water cooling" cycle,the role of rubber concrete compressive strength and splitting tensile strength changes.The test results show that:(1)At the normal temperature of20°C,the reference concrete has the highest compressive strength,but when the temperature rises,the compressive strength decreases drastically,and the higher the temperature,the greater the reduction,resulting in higher relative high temperatures.The compressive strength of benchmark concrete is less than that of rubber concrete.In the range of 20 °C to 120 °C,the compressive strength and splitting tensile strength of the three types of rubber concrete gradually decrease with the increase of temperature,but the composite modified rubber concrete and NaOH solution modified rubber concrete as a whole.The compressive strength and splitting tensile strength of the reference rubber concrete decrease in turn,showing a better pattern.(2)After experiencing the relative high temperatures of 60°C,80°C,and 120°C and natural cooling and cooling down,the compressive strength and splitting tensile strength of the composite modified rubber concrete are still the largest,and the NaOH solution is stillthe largest.Rubber concrete followed,benchmark rubber concrete minimum.(3)In addition to the reference rubber concrete,the compressive strength and split tensile strength of other concrete after water cooling and cooling are smaller than the compressive strength and splitting tensile strength after natural cooling and cooling.(4)With the increase of relative high temperature,no matter whether the temperature is lowered or not,the reference normal concrete and modified rubber concrete all show a decrease in compressive strength and splitting tensile strength with increasing temperature.However,the compressive strength and splitting tensile strength of the reference rubber concrete fluctuate with increasing temperature,especially at 80°C~120°C,both compressive strength and splitting tensile strength increase.(5)Different concretes are higher than the 0th cycle compressive strength and splitting tensile strength after circulating temperature increasing-cooling 50 times.(6)After the "relative high temperature-natural cooling" cycle effect,the concrete compressive strength and splitting tensile strength are significantly higher than the "relative high temperature-water cooling."(7)The compressive strength and splitting tensile strength of the two modified rubber concretes under the conditions of “relative high temperature-free cooling” and “relatively high temperature-water cooling” are almost the same,and are interlaced with changes in the number of warming-cooling cycles.Together,but both compressive strength and splitting tensile strength are greater than the benchmark rubber concrete.