沥青VOCs排放行为及抑制方法研究

采用气体采样袋/气相-色谱质谱法作为沥青VOCs样品采集和分析手段,探明SBS改性沥青VOCs排放量以及物质组成分布,通过引入VOCs抑制剂,量化抑制效果,开发沥青VOCs治理技术。实验结果表明,抑制剂的加入对沥青材料的化学结构和流变性能并未产生显著影响。随着抑制剂含量的增加,沥青VOCs呈现先下降后上升的趋势,当抑制剂的掺量为0.5%时,沥青VOCs的释放量从89.30 mg/m³下降至57.97 mg/m³,抑制效率最高达到35.08%,其主要影响脂肪烃类物质,对其他类别物质影响较小。     

铜基复合材料中增强相结构设计与性能研究进展

铜基复合材料以其优异的电学、耐磨和力学等性能受到了许多学者的重视。近年来,陶瓷颗粒、碳纳米相等因其结构特性和物理性能、力学性能的优异性,已成为铜基复合材料常用的增强相之一。概述了不同增强相(Al₂O₃、CNTs、MAX)增强铜基复合材料的制备方法和综合性能方面的研究进展;阐述了增强相在铜基体中的分散性以及增强相与基体之间的界面结合对铜基复合材料综合性能的影响及强化机制,旨在阐明通过增强相的结构设计实现综合性能良好的铜基复合材料的设计思路。     

Experimental evaluation on high temperature rheological properties of various fiber modified asphalt binders

High temperature rheological properties of fiber modified asphalt binders and impact of the type and content on such properties were studied.Three types of fiber,including polyester(PET),polyacrylonitrile(PAN) and cellulose(CEL),a control content(0%) and four levels of fiber content(2%,4%,6% and 8% by total asphalt binder mass) were used with asphalt binders.The high temperature rheological properties,consisting of complex modulus(G*) and phase angle δ,were measured using SHRP’s dynamic shear rheometer(DSR) between 46-82 ℃.Experimental results indicate that the changes of G* and tan δ of fiber modified asphalt binders with the increase of test temperature tend to slow down,and the temperature susceptibility is improved obviously compared to that of original asphalt binder.Fiber modification results in the increase of rutting parameter(G*/sin δ) at high temperatures,the decrease of temperature susceptibility,and further improved high temperature performance of asphalt binder.An excellent correlation exhibits between fiber content and high temperature performance of asphalt binder.Moreover,fiber type also has different influences on the improvement of G*/sin δ,G*/sin δ of PET and PAN fiber asphalt binders are both higher than that of CEL fiber,but G*/sin δ of CEL fiber is still higher than that of original asphalt.However,there is a critical fiber content when fibers start to interact with each other.Therefore,based on the critical fiber content and economic consideration,the optimum fiber contents for various fiber-modified asphalt binders are obtained.     

钢纤维增强聚合物水泥基复合材料的界面特性

采用聚丙烯酸酯乳液（PAE）、苯乙烯－丙烯酸共聚乳液（SA）、聚乙烯醇缩甲醇水溶液（PVFO）对钢纤维增强水泥基复合材料进行改性,发现聚合物提高了复合材料的宏观性能如抗弯强度、韧性、纤维与水泥基体界面粘结强度。红外光谱分析表明,聚合物加入后其活性团与水泥或集料间发生化学键合,DSC放热曲线表明,加入聚合物后混合物的放热峰值提高,验证了红外光谱的结果。通过聚合物与水泥石之间的化学键合强化了钢纤维与水泥基体间界面,形成强度、韧性很好的具有互穿网络的钢纤维增强水泥基复合材料。     

旧混凝土路面板底脱空的有限元分析

水泥混凝土路面的破坏类型有多种，其中路面板底脱空是水泥混凝土路面板的主要破坏类型。利用ALGOR FEAS公司开发的SAP93软件，采用材料非线性的有限元模型，对路面板底脱空修补前后的受力情况进行了弹塑性分析。分析结果表明，修补后路面板底的应力集中现象得到了明显的改善。     

集料孔隙对沥青吸收和混合料体积性能影响

通过分析沥青混合料集料的孔隙结构 ,探讨了集料孔隙对沥青吸收和沥青混合料体积性能的影响。试验证明 ,集料孔隙对沥青吸收的比例约为 5 %～ 10 % ,由于沥青吸收使最大理论密度变异性较大 ,空隙率差值超过 1% ,VMA差值约为 0 .6 %～ 1.0 %。     

聚合物纤维改性沥青混凝土的研究

路用纤维作为沥青混凝土的添加材料 ,近年来在我国的高级沥青路面得到了广泛应用。通过添加聚合物纤维来对普通沥青混凝土进行改性 ,研究了混合料掺纤维后的马歇尔稳定度、水稳定性、高温稳定性、低温抗裂性及耐疲劳性能 ,并与普通密集配沥青混凝土进行了路用性能的对比分析。依据分析的结果 ,简述了纤维改善沥青混凝土的强度形成机理。     

Property of Anti-Ultraviolet Aging of LDHs Modified Asphalt

LDHs was introduced into 70# asphalt binder by different weight ratio. Asphalt penetration test, soft point test, ductility test, viscosity test, dynamic shear rheometer (DSR) test and Fourier transform infrared (FTIR) test, were conducted to characterize and predict the LDHs modified asphalt. Research results indicated that the LDHs has great effect on resistance to UV of asphalt, which makes the asphalt absorb less ultraviolet radiation under the same UV intensity. Complex modulus, phase angle and FTIR test results indicate that the LDHs can significantly enhance the property of anti-ultraviolet aging of asphalt. The test results show that the LDHs has an obvious improvement on the anti UV aging of asphalt.     

沥青混凝土集料级配的分形特征研究

以散粒体分形模型为基础 ,推导了沥青混合料矿料分布函数。在双对数坐标系里画出 19(或 2 0 )的几种沥青混合料的级配上限、下限、中值曲线 ,经过回归分析 ,得到每种级配集料的分形维数。沥青混合料的矿料分形维数主要由 0 .0 75 mm以下颗粒的多少决定。 0 .0 75 mm以下颗粒越多维数越高 ,反之越少。分形维数的相关性越高 ,集料级配越连续。分形维数越高 ,集料越细。分形维数和相关性可以作为集料级配评价的量化指标。     

阻燃油毡的阻燃机理研究

本文对阻燃油毡，采用红外光谱法和差热—热失重法对阻燃机理进行了研究