| Because of the advantages of application of asphalt concrete,asphalt concrete gradually replace cement concrete in high grade pavement,but the hot asphalt mixture due to the high requirements of construction temperature,often more than 160℃,modified asphalt temperature requirements are higher,resulting in the pollution of the environment,as well as the workers and residents in the body damage.With the warm mix asphalt(Warm Mix Asphalt,WMA)technology,to solve this problem,the advantages of warm mix asphalt concrete is green and environmental protection.In this paper,JY-W1 asphalt mixing agent is supplied by Jiangsu Jinyang new Mstar Technology Ltd.The Marshall test molding specimen and small beam specimens,respectively,with high and low temperature test,evaluation of warm mix asphalt mixture and ordinary asphalt mixture of different performance of three kinds of SMA-16,SMA-13,SMA-10 graded by the comprehensive evaluation for the performance of asphalt mastic,and warm mix agent on SMA three the influence of gradation.Through high and low temperature test,the performance of warm mix agent in summer and winter was evaluated.The main conclusions are as follows:(1)After adding the warm mixture,the softening point of asphalt has a certain range of improvement,which shows that the warm mix makes the high temperature performance of asphalt increase a certain extent,and the rutting resistance is improved after the formation of mixed material.It has certain influence on the penetration of asphalt,and makes the penetration of the needle become smaller.It shows that the temperature mixing agent has certain influence on the asphalt properties,which makes the consistency and hardness of asphalt become larger,and increases the ability of asphalt to endure deformation.Under the condition of 10℃,the ductility of the asphalt can be increased obviously after adding the modifier,indicating that the low temperature performance of the asphalt can be improved to a certain extent by the warm mixing agent.(2)SMA-10 can significantly reduce the void fraction by changing the number of compaction,while SMA-16 is not obvious,but by increasing the number of compaction will destroy the integrity of the test block.By adding warm mix agent,from the three kinds of temperature to reduce the porosity of the effect of comprehensive view,135℃is the best mixing temperature.(3)From the stability of asphalt mixture:①Stability of SMA-10,hit 50 times,adding warm mix agent,stability in mixing temperature is 155℃ increased to a maximum value,and hit 75 times,155℃ for maximum stability,compaction 50 times and 75 times the corresponding mixing temperature is 155℃ are similar.②The stability of the SMA-13,the whole stability of the compaction of the 75 have been improved,and the stability was decreased after adding the warm mixing agent.The two kinds of compaction times and the stability at 145℃ were better.③ The stability of SMA-16,when the compaction was 50 times,the stability of the mixture was reduced after adding the warm mix agent,and the stability increased with the addition of the warm mix agent for the 75 times,and the growth rate was obvious at the temperature of 155.Without heating agent,the stability decreased obviously when the compaction was 75 times.④After adding warm mix agent,the flow value is generally reduced,or similar to ordinary hot mix asphalt,indicating that warm mix asphalt mixture to enhance the ability to withstand deformation.⑤From the point of view of Marshall modulus,the number of SMA-10 compaction recommended 50 times,the temperature is selected at 155℃.The number of SMA-13 compaction recommended 50 times,the temperature of the choice of 135℃.The number of SMA-16 compaction recommended 75 times,the temperature of the choice of 155℃.(4)From the destruction of the tensile strength,SMA-10 and SMA-13 reached the maximum at 145℃,and this kind of grading SMA-16 when adding warm mix agent has little effect on its low temperature strength.From the destruction of maximum bending strain,after adding warm mix agent,the SMA-10 strain decreased,SMA-13 at 145℃ reached maximum strain,SMA-16 gets the maximum value at 155℃,but at 145℃ also increased,considered in the economic aspect,can also choose 145℃.Choose the temperature from damage stiffness modulus,adding warm mix agent SMA-10 gradation,asphalt modulus increased,resulting in low temperature ductility decrease,asphalt flexibility poor crack resistance also decreased,the specimen is more prone to cracking,reduce the low temperature performance of asphalt.When the SMA-13 mixture is added into the warm mix agent,the growth rate is larger when the modulus is 155℃ and the temperature of 135 ℃,and the crack resistance of the asphalt is significantly reduced,and the temperature is slightly increased at the temperature of 145℃,this temperature can be used as the optimum temperature.When the SMA-16 mixture was added into the warm mix agent,the modulus was reduced at 145℃ the low temperature ductility of asphalt was increased,the flexibility and crack resistance were better,and the low temperature performance of asphalt was improved.On the whole,after adding warm mix agent,the optimum temperature is 145. |
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