Study On The Pavement Performance Of Sisal Fibers Asphalt Concrete

Since Reform and Opening Up, highway construction andmaintenance investments are growing larger and larger along with therapid development of China's highway construction, but because roadconstruction quality and service life can not satisfy the growing demandtravel and transportation, high construction and maintenance costshave seriously hampered the construction process of highway. At the sametime, vehicles large scalization and increase of heavy loading andoverloading rate also made a higher demand to quality and maintenancemanagement works of highway construction. Therefore, improving thequality construction of highway and extending the service life ofpavement can improve people's satisfaction with highway usage andreduce highway maintenance costs. To achieve this goal, this articleattempted to blended sisal fibers into the asphalt concrete. The testproved that such an attempt achieved a certain effect.The subject mainly researched the impact on pavement performancethrough adding sisal fibers to asphalt concrete. Considering low-costsnature of sisal fibers as well as its enhancement effect to cement concrete,this paper incorporated sisal fibers into the asphalt concrete for the firsttime, through laboratory tests validated using performance of sisal fibersAsphalt Concrete Pavement. The test was completed in the Xiaogan andXianning Conservation Center of Beijing-Zhuhai Expressway in July 2008and November 2009 respectively. Laboratory tests conducted Marshalltest, high temperature anti-vehicle test and low temperature cracking testthree types of pavement structures—AC-13, AC-20 and SMA-13. Inthe three kinds of pavement structure types obtained by the tests, only thedense gradation asphalt mixture of AC-13 is suitable to add sisal fibers.According to the types and density difference of mineral aggregateswhich chosen by the Xiaogan and Xianning Test Center of Beijing-ZhuhaiExpressway, we did mineral aggregate composition design and oil-stoneratio design on the basis of doing tests to raw materials; through addingdifferent specifications of sisal fibers into asphalt mixtures to verify theirenhanced action to the asphalt mixtures. In the tests, used differentlengths (4mm, 7mm, 10mm) and different quality dosages (0%, 0.1%,0.2%, 0.3%) of sisal fibers, carried out multiple sets of Marshallconventional tests and residual stability contrast tests, and throughmulti-group Rut tests and freeze-thaw fracturing tests to validate them to determine that for the AC-13 pavement structure, sisal fibers'optimumlength is 6mm, with best quality dosage of 0.2%. Laboratory tests showedthat admixing the appropriate specifications of sisal fibers to asphaltmixtures could improve their physical mechanical indicators and roadperformance such as high temperature stability, low temperature crackresistance, water stability and so on. Moreover, since the low-cost natureof sisal fibers, compared to polypropylene fibers which are more maturelyused, the per ton of mixtures could save about 12 Yuan of the cost of fiberadditives, per kilometer highway could save about 24,000 Yuan of thecost of fiber additives. The economic benefits are significant.If the research results of this subject can be used widely, it cangreatly increase our highway construction quality and level; can largelyreduce increased costs caused by adding fibers. The successfuldevelopment of sisal fibers will produce huge economic and socialbenefits.