玄武岩纤维SMA-13混合料设计及路用性能试验研究

发布时间：2018-07-17 01:47

【摘要】：SMA是由沥青胶结料组成的沥青玛蹄脂填充于间断级配的粗集料骨架空隙而组成一体的沥青混合料,性能良好,被广泛应用于高等级沥青路面结构当中。在SMA的组成成分当中,起到稳定作用的纤维尤为重要。研究发现,玄武岩纤维有着良好的物理化学性质,且绿色环保,生产工艺简单,性价比较高,可以替代SMA中常用的木质纤维,能克服木质素纤维易吸水、耐热性差、耐磨性差等缺点。根据理论研究和工程实例的查阅,本文开展对SMA玄武岩纤维沥青胶浆及混合料的研究。首先,通过对玄武岩纤维掺量为0%、1%、2%、2.5%、3%、3.5%、4%以及长度为3mm、6mm、9mm的沥青胶浆分别进行软化点、测力延度、弹性恢复以及锥入度试验,以分析玄武岩纤维分散于沥青胶浆中起到的作用以及纤维掺量和长度的改变对沥青胶浆的影响,结果表明,玄武岩纤维能够提高沥青抵抗温度变化的能力以及抗剪切性能,而变形恢复能力以及延展性有所下降,因此需要寻找合适的玄武岩纤维掺量以及纤维长度。然后,以响应曲面试验设计优化方法,取玄武岩纤维掺量0.25%~0.55%、纤维长度3mm~9mm、油石比6.4%~6.8%为影响因素,取稳定度、流值、空隙率、矿料间隙率、沥青饱和度作为响应指标进行三因素三水平的试验设计,对实验结果进行汇总,拟合出每种响应指标与三种影响因素的函数关系式,并对函数进行方差分析检验,而后绘制出在每两种影响因素交互作用下对各项指标的响应曲面图,综合各响应指标的最优值,对影响因素进行优化设计,最终得出考虑沥青混合料马歇尔指标期望值条件下玄武岩纤维在沥青混合料中的最佳掺量为0.38%,纤维的最佳长度为6mm,以及最佳油石比为6.56%。最后,将优化设计的玄武岩纤维SMA沥青混合料与实际工程当中所用木质素纤维SMA沥青混合料分别进行车辙试验、低温间接拉伸试验、浸水马歇尔试验以及冻融劈裂试验,结果表明,玄武岩纤维沥青混合料在高温稳定性、水稳定性、低温抗裂性方面都优于木质纤维沥青混合料,其中在低温抗裂性方面尤为突出,提高50.5%。对玄武岩纤维沥青试件开裂部分进行电镜扫描分析,从微观上为玄武岩纤维在沥青混合料中发挥的功效提供理论依据,最后结合当前沥青混合料原材料市场价格,对玄武岩纤维和木质纤维在SMA中的应用做经济社会效益对比分析。
[Abstract]:SMA is a kind of asphalt mixture composed of bituminous matte filled with coarse aggregate skeleton voids with discontinuous gradation. It has good performance and is widely used in high grade asphalt pavement structure. Among the components of SMA, fibers that play a stabilizing role are particularly important. It is found that basalt fiber has good physical and chemical properties, green environmental protection, simple production process and high cost performance ratio. It can replace the commonly used wood fibers in SMA, and can overcome the poor water absorption and heat resistance of lignin fibers. Poor wear resistance and other shortcomings. On the basis of theoretical research and engineering examples, the research on SMA basalt fiber asphalt mortar and mixture is carried out in this paper. First of all, by testing the softening point, force ductility, elastic recovery and cone penetration of asphalt mortar of 3. 5% and 3. 5% and 6 mm / 9 mm in length, respectively. The effect of basalt fiber dispersion in asphalt slurry and the influence of fiber content and length on asphalt mortar are analyzed. The results show that basalt fiber can improve asphalt resistance to temperature change and shear resistance. However, the deformation recovery ability and ductility are decreased, so it is necessary to find suitable basalt fiber content and fiber length. Then, with the optimum design method of response surface test, taking the basalt fiber content 0.250.55, fiber length 3mm / 9mm, oil stone ratio 6.4g 6.8% as the influencing factors, taking the stability, flow value, void ratio, mineral interstitial ratio, The experimental design of three factors and three levels of asphalt saturation is carried out as a response index. The experimental results are summarized, and the functional relations between each response index and the three influencing factors are fitted out, and the variance analysis of the function is carried out. Then draw the response surface map of each index under the interaction of each two factors, synthesize the optimum value of each response index, carry on the optimization design to the influence factor. Finally, the optimum content of basalt fiber in asphalt mixture is 0.38, the optimum length of fiber is 6 mm, and the optimum ratio of oil to stone is 6.56, considering the expected value of Marshall index of asphalt mixture. Finally, the optimized design of basalt fiber SMA asphalt mixture and the lignin fiber SMA asphalt mixture used in the actual project were carried out rutting test, low temperature indirect tensile test, immersion Marshall test and freeze-thaw splitting test, respectively. The results show that basalt fiber asphalt mixture is superior to wood fiber asphalt mixture in high temperature stability, water stability and low temperature crack resistance. Scanning electron microscope (SEM) scanning analysis is carried out on the cracking part of asphalt specimen of basalt fiber, which provides a theoretical basis for the function of basalt fiber in asphalt mixture microscopically. Finally, combined with the market price of raw materials of asphalt mixture at present, The economic and social benefits of basalt fiber and wood fiber in SMA were compared and analyzed.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U414

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