| Compared with other impermeable materials,asphalt concrete has the following advantages: good impermeability,strong ability to adapt to deformation,self-healing ability,easy construction and later maintenance,so more and more hydraulic structures choose asphalt concrete as the impermeable material of the dam body.In practical engineering,because asphalt concrete is immersed in water for a long time,water molecules are immersed in the interface between asphalt and aggregate,reducing the adhesion between asphalt and aggregate,thus leading to the occurrence of water damage phenomenon.Water damage will not only reduce the water resistance of asphalt concrete,but also affect other properties,such as slope stability,etc.This paper studies the influence of different degrees of water damage on slope stability,aiming at providing guidance for the construction and maintenance of hydraulic asphalt concrete to prevent water damage.Through studying the influence of anti-stripping agent on the asphalt-aggregate adhesion and the water stability of asphalt concrete,as well as the influence of water damage on the stability of asphalt concrete slope,the research conclusions are as follows:(1)Firstly,the physical properties of asphalt and aggregate were tested to evaluate whether their physical properties met the requirements of the test specification.The results showed that the properties of raw materials met the quality inspection requirements in the design specification.(2)Second,the study of adding antistripping agent to asphalt,aggregate adhesive,the influence of acidic aggregate gneiss and granite in different doses of antistripping agent respectively,and not adding antistripping agent,alkaline limestone,using two different evaluation method(boiled method and photoelectric colorimetry)test adhesion of asphalt and aggregate,and compared the difference between two evaluation methods.The test results show that with the increase of anti-stripping agent content,the adhesion performance between asphalt and acid aggregate increases significantly and can reach the adhesion level of limestone.Compared with the water boiling method,the evaluation result of photoelectric colorimetric method is more intuitive and clear.(3)To study the influence of anti-stripping agent on the water stability of formed asphalt concrete specimen,the acid aggregate gneiss was added with anti-stripping agent of 0.2%,0.4%,0.6%,0.8% and 1.0% respectively.The water stability of asphalt concrete specimen was built according to the test specification and tested.The results showed that with the increase of anti-stripping agent content,The water stability coefficient increases gradually and its value is greater than 0.9,indicating that the anti-stripping agent can effectively improve the water resistance of asphalt concrete.(4)Finally,the influence of long-term immersion on the stability of asphalt concrete slope is studied.According to the selected raw materials and mix ratio,the asphalt concrete Marshall specimen is formed respectively.The formed specimens were immersed in water at four temperatures(20℃,40℃,60℃,80℃)for different times(2 days,4 days,8 days,16 days,32 days,64 days,128 days)to conduct slope flow and splitting strength tests.The results show that with the increase of immersion time and water bath temperature,the flow value of asphalt concrete slope increases in a logarithmic form,and the increase rate gradually tends to be gentle,while the change of its splitting strength value is on the contrary,and gradually decreases. |
PDF Full Text Request