低温地区桥面纤维浇注式沥青混合料的低温性能研究

Study on Low Temperature Performance of Bridge Deck Fiber Pouring Asphalt Mixture in Low Temperature Area

为了研究低温地区钢桥面铺装纤维浇注式沥青混合料的低温抗裂性能,选用基质、SBS、浇注式及纤维浇注式沥青混合料为研究对象,针对不同低温情况下的各沥青混合料进行低温小梁弯曲试验、低温弯曲蠕变试验以及低温劈裂试验,得出以下结论:(1)基质、SBS、浇注式及纤维浇注式沥青混合料的劲度模量、弯曲蠕变柔量及劈裂极限应变随着温度的降低均呈逐渐减小变化,而低温劈裂强度则呈先增后减变化;(2)纤维的掺入能够明显增强浇注式沥青混合料的低温抗裂性能,BF纤维对浇注式沥青混合料的低温抗裂性能改善效果优于PF和LF纤维;(3)纤维浇注式沥青混合料的低温劈裂试验变化规律表现较于低温小梁弯曲和弯曲蠕变试验更为敏感,故建议采用低温劈裂试验来评价低温地区纤维浇注式沥青混合料的低温稳定性能。

In order to study the crack resistance of asphalt mixture of steel deck pavement in low temperature area,select the matrix,SBS,pouring type and fiber pouring type asphalt mixture,conduct low temperature trabecular bending test,low temperature bending creep test and low temperature splitting test for each asphalt mixture at different low temperatures,here′s the following conclusions:(1)The strength modulus,bending creep flexibility and splitting limit strain of the substrate,SBS,pouring type and fiber pouring type asphalt mixture are all gradually decreasing with the decrease of temperature,the low-temperature splitting strength increased first and then decreased;(2)The incorporation of fiber can significantly enhance the low temperature crack resistance of poured asphalt mixture,the improvement effect of BF fiber on the low temperature crack resistance of poured asphalt mixture is obviously better than that of PF and LF fiber;(3)The change pattern of low temperature splitting test of fiber pouring asphalt mixture is more sensitive than that of low temperature trabecular bending and bending creep test.Therefore,it is recommended to evaluate the low temperature stability of fiber pouring asphalt mixture in cold areas.