Study On The Durability Trial Method Of Chip Seal

With the rapid development of Chinese transportation, especially the construction of asphalt concrete highway, the early damage is becoming a increasingly serious problems, the people pay more and more attention to the road for the preventive maintenance, so people pay growing attention to the preventive maintenance for the road. Chip seal has very good abrasion resistance and skid resistance, convenient construction, cheap and applicable, so it has been widely applied in pavement maintenance; however, it has been seriously damaged during the use process, use life shortens greatly compared with other countries, so the research on durability of chip seal is very important.Chip seal's durability presents a rapid decline trend under the effect of environment and load, mainly includes the gravel peel and sliding performance reduced, the damage has great influence of the pavement performance. This article researched the durability on chip seal mainly from the asphalt's low temperature bond property, the texture depth and friction coefficient.There are many factors that can affect the durability on chip seal, the choosing of raw materials, design and construction, use conditions and act. In the selection of raw materials, not only should consider the kind of asphalt and rubble, but also strictly controlled its dosage and size; in the design and construction process we should fully consider the chip seal's working principle and the using conditions, strictly abide by the relevant design standard.The asphalt's low temperature bond property is the main factors for gravel peel. Improved the test method based on the Vialit test specification, tested the low temperature bond properties of matrix asphalt, rubber asphalt, TLA lake modified asphalt. Gravel using 4.75～9.5mm single particle size distribution of basalt,150g asphalt content can meet the requirements of 2/3H, ball's height choose 75 cm can provide enough impact energy; By changing the temperature (-20℃,-15℃,-10℃,-5℃,0℃,5℃,10℃) to find different asphalt's test temperature. Do low-temperature binding test in the corresponding temperature conditions freeze-thaw cycle. The test results show that, the improved Vialit test can reflect the asphalt's low temperature bond property very well, it's an effective evaluation index of chip seal's durability.The texture depth and friction coefficient of chip seal can reflect its sliding performance very well. Mold specimen through the improvement of rutting test apparatus, maintain in different temperature respectively (30℃,45℃,60℃), Crush 1h every 10h, and measure the tectonic depth and friction coefficient timely. Test results show that, the tectonic depth and friction change more obviously when the maintenance and test in higher temperature, finally all tend to a fixed value. Thus they are ffective evaluation index of chip seal's durability.