SMA沥青混合料体积指标计算方法的探讨

Study on Calculation Methods of Volume Indexes for Stone Mastic Asphalt(SMA)

根据《公路工程沥青及沥青混合料试验规程》的现行试验规程(JTG E20—2011)和原试验规程(JTJ 052—2000)规定的沥青混合料体积指标计算方法,比较了不同体积指标计算方法所得SMA沥青混合料的体积指标的差异。结果表明:采用现行试验规程计算时,沥青混合料的矿料间隙率(VMA)和有效沥青饱和度(VFA)的计算结果要比按原试验规程时的计算结果显著减小,并导致某些SMA沥青混合料的VMA计算结果难以满足现行施工技术规范的要求。结合有关试验结果和工程实践经验,建议现行施工技术规范对SMA沥青混合料的VMA最小要求值宜适当降低。

With the use of the Standard Test Methods of Bitumen and Bituminous Mixtures for Highway Engineering(JTG E20-2011)and the previous version(JTJ 052-2000) the results of volume indexes of Stone Mastic Asphalt(SMA) were obtained and compared.The results show that under the current method the results of voids in mineral aggregate(VMA) and voids filled with asphalt(VFA)are significantly smaller than those under the previous method,which makes it difficult for some asphalt mixtures to meet the requirement of current construction specifications for the VMA index.Therefore,based on the test results and practical construction experiences,it would be appropriate to lower the minimal requirement value of VMA index in current construction specification.