透水铺装改性基层对典型径流污染物动态除污实验研究

为提高透水铺装对雨水径流的净化作用,通过优选骨料和掺入添加剂的方法对透水铺装基层进行改性,制备了沸石基层、陶粒基层、掺粉煤灰砾石基层和掺膨润土砾石基层;同时制备一组传统砾石基层作为参照对比基层;并将改性后的基层和参照基层对雨水径流典型污染物COD、TP、TN、Cu^(2+)的削减作用进行了过滤吸附实验。实验结果表明,4种改性基层对污染物去除能力整体上较传统砾石基层均有一定程度的提高;但不同改性方法对污染物的去除效果差异较大。整体来看,掺膨润土砾石基层对污染物COD、TP、Cu^(2+)的去除效果最好;但在去除TN的实验中,除沸石基层外,其他基层对TN的去除效果皆不理想。研究结果表明,过滤除污实验中,掺入添加剂方面改性,掺膨润改性基层对于污染物削减效果最好;而掺入骨料方面,沸石改性基层去除效果最佳。建议将沸石作为骨料,膨润土作为添加剂制成改性基层,以最大化实现去除污染物的作用。

制样方法对高聚物改性沥青基层处理剂粘结强度影响的比较研究

粘接强度是评价防水涂料与基层粘结性能的重要指标。研究讨论了不同标准、不同制样方法对高聚物改性沥青基层处理剂粘结强度指标测试结果的影响,得到最优的制样和测试方法,为低固含量、低黏度、具有优异流动性的涂料产品(类似高聚物改性沥青基层处理剂产品)采用“8”字水泥砂浆块测试粘结强度指标(GB/T 16777—2008标准中的B法)的方法提供一定的理论依据。

Friction and wear behaviors of Nb-Ti-Si-Cr based ultrahigh temperature alloy and its Zr-Y jointly modified silicide coatings

Zr-Y jointly modified silicide coatings were prepared on an Nb-Ti-Si-Cr based ultrahigh temperature alloy by pack cementation process. The wear behaviors of both the base alloy and coatings were comparatively studied at room temperature and 800 ℃ using SiC balls as the counterpart. The Zr-Y jointly modified silicide coating is mainly composed of a thick （Nb,X）Si2 outer layer and a thin （Ti,Nb）5Si4 inner layer. The coatings possess much higher microhardness than the base alloy. The wear rates of both the base alloy and coatings increase with increasing the sliding loads. However, the coatings have much lower wear rates than the base alloy under the same sliding conditions. The coatings have superior anti-friction property, and can provide effective protection for the base alloy at both room temperature and 800 ℃ in air.

Surface modification of calcium carbonate:A review of theories,methods and applications

Calcium carbonate,which is widely employed as a filler added into the polymer matrix,has large numbers of applications owing to the excellent properties such as low cost,non-toxicity,high natural reserves and biocompatibility.Nevertheless,in order to obtain the good filling effect,calcium carbonate needs to be surface modified by organic molecules so as to enhance the dispersion and compatibility within the composites.This review paper systematically introduces the theory,methods,and applications progress of calcium carbonate with surface modification.Additionally,the key factors that affect the properties of the composites as well as the current difficulties and challenges are highlighted.The current research progress and potential application prospects of calcium carbonate in the fields of plastics,rubber,paper,medicine and environmental protection are discussed as well.Generally,this review can provide valuable reference for the modification and comprehensive utilization of calcium carbonate.

沪杭客运专线T梁防水施工技术

沪杭客运专线是我国"四纵四横"客运专线的重要组成部分,工程量大,施工要求高,本文重点介绍了T梁的防水设计与施工。该T梁桥面防水采用铁路桥专用高聚物改性沥青防水卷材及配套基层处理剂,工程完成后,达到了预期的防水效果。

桥梁施工中防水施工技术的应用

桥梁工程在我国的交通路网体系中占据重要的地位,其建设质量直接关系我国的路网工程建设水平,对区域经济发展也具有较为直观的影响。但在近些年,桥梁工程项目建设数量不断增大的形势下,其中也暴露出了很多施工问题,对桥梁工程的安全使用构成了较大的影响,较为典型的问题便是桥梁结构的防水施工问题,由于桥梁施工的施工环境较为复杂,防水施工的难度偏大,很可能限制桥梁工程的整体建设效果。因此,本文以具体的桥梁工程为例,重点研究防水施工技术的应用要点,以期规范防水施工行为,全面提升桥梁工程的整体防水效果,提高桥梁结构的稳定性。