| Due to the excellent high temperature stability and low temperature crack resistance of modified asphalt with high content SBS,it was widely used in porous asphalt mixtures,stress absorbing layers,waterproof materials,etc.However,there are still some problems in the preparation and application of modified asphalt with high content SBS.On the one hand,the compatibility between the asphalt phase and the modifier phase is poor when the content of SBS is high,and the choice of the matrix asphalt and SBS is critical to its compatibility.On the other hand,in the application process of the modified asphalt with high content SBS,the aging phenomenon will inevitably occur due to the influence of light,heat and humidity.On the basis of this,it is of great significance to investigate the material composition and anti-aging properties of modified asphalt with high content SBS.This paper mainly studied the modified asphalt with high content SBS from two aspects of material composition and anti-aging performance.First of all,different matrix asphalt and SBS were selected,and the influences of the type and proportion of matrix asphalt and SBS modifier on the basic properties of high content SBS modified asphalt were analyzed.Secondly,the high-content SBS modified asphalt with heat stabilizer or light stabilizer was prepared respectively,and then the heat-light-oxygen aging test and hydrothermal aging test were designed to simulate the effect of natural environment on its anti-aging performance.Finally,the infrared spectroscopy and thermogravimetric analysis of the aging residue were carried out to reveal the aging mechanism of modified asphalt with high content of SBS.The results of basic test show that when the matrix asphalt is compounded with 70# and 200#,90# and 200#,and the compounding ratio is 6:4 and 7:3 respectively,the basic performance of the high-content SBS modified asphalt prepared is excellent,and the compatibility between matrix asphalt and modifier is better.By comparing the effects of different types of SBS and blending amount on the performance of modified asphalt,two star-shaped SBS modifiers were recommended and their reasonable blending amount was determined.The results of FTIR and TG show that: compared with unstabilized stabilizers,after thermal oxygen aging,the carbonyl index CI of the two modified asphalts with heat stabilizers decreased to 0.015 and 0.017 respectively,both decrease rates were close to 50%,and the butadiene index BI increased.The quality loss rates decreased by 1.6% and 1.8% respectively.After humid heat aging,the carbonyl index CI of the two modified asphalts with heat stabilizers were reduced to 0.035 and 0.033,respectively,and the mass loss rate was decreased by 1.6% and 1.4%,respectively.After photo-oxygen aging,the carbonyl index CI of the two modified asphalts,mixed with the heat stabilizers and light stabilizers,decreased to 0.031 and 0.038,respectively,the butadiene index BI index increased to 0.127 and 0.121,respectively,and the mass loss rate decreased by 5.8% and 5.5%,respectively.It can be seen that both the heat stabilizer and the light stabilizer can improve the anti-aging performance of the modified asphalt,and the effect of the light stabilizer is more significant.Through the optimization of composition of modified asphalt with high content SBS materials and the investigation of anti-aging properties,the reasonable material composition and anti-heat-light-oxygen aging measures of high-content SBS modified asphalt were obtained.The results are of great significance to the application of high-content SBS modified asphalt in the field of pavement engineering and waterproof engineering. |
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