Effect of PDMS content on waterproofing and mechanical properties of geopolymer composites

The present study mainly studies the effect of polydimethylsiloxane (PDMS) content on the waterproofing and mechanical properties of geopolymer composites. Firstly, hydrophobic modified geopolymer composites (HM-GC) were prepared by adding PDMS during the mixing process. Secondly, the surface wettability characteristics, water absorption, uniaxial compressive and tensile properties of HM-GC were investigated. The effect of PDMS content on the waterproofing and mechanical properties was further discussed. Finally, considering the waterproofing and mechanical properties, the optimal PDMS content was proposed. The results showed that with increasing PDMS content, the contact angle of geopolymer composites rapidly increase at first and then stabilizes. The geopolymer composites with 4% and 5% PDMS content exhibit overhydrophobic surface wettability. In addition, the water absorption gradually decreases with increasing PDMS content, indicating an improvement in the waterproofing ability. The incorporation of PDMS can enhance the compressive properties of geopolymer composites while reducing the tensile properties. Comprehensively considering the waterproofing and mechanical properties, it is reasonable to select 4% as the optimal PDMS content used in practical marine engineering.     

Behavior of a mechanically anchored waterproofing membrane system under wind suction and uniform Pressure

A pressure and wind tunnel test was conducted to obtain the basic data for wind resistance design of a mechanically anchored waterproofing membrane system. The test specimen was a flat roof with the following dimensions: 2.4 m in width, 3 m in length and 0.29 m in height. The waterproofing material was polyvinyl chloride sheet reinforced with polyester fiber (PVC sheets). In the pressure test, because the applied pressure was equivalent to the pressure on the entire surface area of the roof, the billowing heights of the PVC sheet around the fastener had almost the same maximum values; therefore, the axial force at the fastener was also similar to the pressure induced by a compressor, and no lateral forces were measured. On the other hand, in the wind tunnel test, the strain of the PVC sheet around the fastener at windward side was larger than that of the leeward side. The lateral force was 70% of the axial force at a mean wind speed of 38.6 m/s. Therefore, it was clear that the characteristics of the mechanically anchored waterproofing membrane system in the pressure test and the wind tunnel test were different.     

浅谈弹性体改性沥青防水卷材

弹性体改性沥青防水卷材SBS,是一种性能优良、应用广泛的卷材。本文通过大量的力学性能实验和对实验数据的研究分析,得出弹性体改性沥青防水卷材的一些力学性能,并进一步的加深了对它的认识,有利于它的推广应用。     

低温沥青基防水卷材粘结剂的研制及其应用

沥青基防水卷材是我国防水材料的重要组成部分,其热熔施工工艺日趋成熟,但冷施工方面一直没有很好的施工材料。本工艺立足沥青基防水材料,通过对改性材料、溶剂、助剂、生产工艺的考察,可以生产出施工需要的低温沥青基防水卷材冷粘结剂。     

如何使用UCD函数实现特殊功能

UCD函数是Authorware的外部函数。本文通过几个实例,介绍了使用UCD函数扩展Authorware功能的方法。     

永磁同步电动机幅频特性分析

分析了水磁同步电动机带惯量负载情况下的幅频特性.从非线性传递函数理论出发,指出永磁同步电动机的幅频特性不仅与电机的参数有关,而用与给定信号有关.随着给定信号的增大,电动机系统的幅频特性曲线发生变化,表现出较强的非线性特点.最后,文中给出了相应的实验结果,验证了理论分析的正确性.     

加快推行防水工程质量保证期制度

防水工程的保修期制度存在诸多问题。已不能适应当前提高防水工程质量的迫切要求。笔者认为我国实际防水工程保证期制度的时机和条件已成熟，呼吁尽快在我国实行保证期制度。     

皮革防水（Ⅱ）

以国产材料为主对多种类型的皮革防水材料的防水性和其它特性进行了比较，指明了它们各自的特点和结合使用好处，同时对不同涂饰剂对皮革防水性的影响进行了比较。     

自粘聚合物改性沥青聚酯胎防水卷材的研制

介绍了一种可用于潮湿基面施工的自粘聚合物改性沥青聚酯胎防水卷材的研制过程，同时对产品性能、特点及可用的施工应用方法进行了阐述。     

Phase behavior of mixtures of ionic liquids and organic solvents

A corresponding-states form of the generalized van der Waals equation, previously developed for mixtures of an ionic liquid and a supercritical solute, is here extended to mixtures including an ionic liquid and a solvent (water or organic). Group contributions to characteristic parameters are implemented, leading to an entirely predictive method for densities of mixed compressed ionic liquids. Quantitative agreement with experimental data is obtained over wide ranges of conditions. Previously, the method has been applied to solubilities of sparingly soluble gases in ionic liquids and in organic solvents. Here we show results for heavier and more-than-sparingly solutes such as carbon dioxide and propane in ionic liquids.