共查询到18条相似文献,搜索用时 125 毫秒
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在水溶液体系中,以过硫酸盐为引发剂,采用正交实验分析法,研究了带羧基、磺酸基、聚氧化乙烯链脂活性基团的摩尔数比及反应温度、反应时间、引发剂的用量等因素对聚羧酸系减水剂性能的影响,得出了合成聚羧酸系减水剂的一种最佳配比和条件,产品性能的试验结果表明,该减水剂具有优良的分散能力与流动保持性,水泥浆体黏聚性好。 相似文献
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聚羧酸系高性能减水剂的试验研究 总被引:17,自引:0,他引:17
采用正交试验分析法 ,研究了带活性基团羧基、磺酸基、聚氧化乙烯链基等不饱和单体的摩尔比及聚氧化乙烯链的聚合度等对聚羧酸系减水剂性能的影响 ,提出一种合成聚羧酸系高性能减水剂的最佳配方。通过有关对比试验的结果说明 ,该产品与国内外一些产品相比 ,具有掺量低、减水率高、流动性损失小及缓凝时间短、早强效果明显等特点 相似文献
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通过确定不同的引发剂用量、聚乙二醇投入量、聚氧化乙烯侧链长度以及酯化反应的温度和时间,对所合成的新型聚羧酸系外加剂的性能进行比较。试验结果表明,在新型聚羧酸系外加剂的合成过程中,存在着最佳范围的引发剂用量、聚乙二醇投入量、聚氧化乙烯侧链长度和最佳的酯化反应温度和时间,优化了新型聚羧酸外加剂的合成工艺。 相似文献
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黄福仁张金龙邵强胡家兵钟开红 《新型建筑材料》2023,(1):46-51
系统研究了三聚磷酸钠、葡萄糖酸钠、羟丙基甲基纤维素醚和硫代硫酸钠等4种常用复配功能组分对聚羧酸减水剂防腐性能的影响。试验结果表明:三聚磷酸钠可有效提高减水剂的防腐性能,而添加葡萄糖酸钠、羟丙基甲基纤维素醚和硫代硫酸钠的聚羧酸减水剂的防腐性能依次降低;混凝土试验表明,变质程度越高的聚羧酸减水剂其性能劣化越严重,减水和保坍性能越差,混凝土凝结时间越短,且抗压强度越低。 相似文献
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本文通过测量聚羧酸系减水剂的减水率、保坍性能、强度、容重等指标,研究了三萜皂甙类、聚醚类引气剂在聚羧酸系减水剂复配中的应用。试验结果表明:掺入适量引气剂可以提高聚羧酸系减水剂的减水率,改善聚羧酸系减水剂保坍性能。引气剂种类和剂量必须根据混凝土试验确定。 相似文献
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Performance control (PC) is the important mental task that is or should be the cornerstone of earthquake-resistant structural design. The fundamental notion behind PC is that the seismic structural response is largely a function of design and detailing, rather than conventional analysis. PC is a design strategy in which the strength, stiffness and other characteristics of groups of members are induced in accordance with predetermined objectives rather than investigated with respect to certain design criteria. PC methodology enables engineers to predict and control structural damage at preselected response stages such as at first yield, any fraction of the failure load or allowable drift ratio, etc. PC provides a wealth of important information that may not be readily available through traditional methods of design. The ultimate failure load solutions are “unique” and suitable for plastic design treatment in that they include P-delta and stiffness degradation effects, and satisfy the prescribed yield criteria as well as boundary support and static equilibrium conditions. The proposed procedures for seismic design of moment frames are entirely suitable for manual computations. The paper does not address irregularities in earthquake-resistant moment frames. 相似文献
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如何安全高效地应用聚羧酸系减水剂 总被引:3,自引:0,他引:3
尽管聚羧酸系减水剂被看作是高性能的、绿色的和最有前途的减水剂品种,但其在实际应用中却暴露出许多较复杂且一时难以解决的技术问题.通过分析聚羧酸系减水剂区别于传统减水剂的性能特点和由此对混凝土性能产生的各种影响,最后就实际工程如何安全高效地应用聚羧酸系减水剂,提出可操作性的合理化建议. 相似文献
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中南世纪城33号楼住宅工程,竖向构件设计使用预制PC板,浆锚连接,与水平构件连接采用钢筋与后浇混凝土结合,通过介绍PC板预制、脱模、安装与调整、与水平构件连接等施工工艺以及质量控制要求,为相关工程施工提供了经验借鉴。 相似文献
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在天然光的利用过程中关键是处理好采光口的窗体设计.从窗体不同部分的不同功能定位出发,通过遮阳板、室内反光搁板、百叶窗、窗帘等构配件对直射光的遮挡、反射和漫射光的利用进行了分析,进而对天然采光中最常见的侧窗窗体的设计方法进行了相应的探讨. 相似文献
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Evaluated here are the inhibitory effects on blue-green algae (Microcystis aeruginosa) produced by nine plant-producing phenols (caffeic, p-coumaric, ferulic, protocatechuic, sinapic, syringic, and vanillic acids, catechol, and hydroquinone), two plant-produced acids (quinic and shikimic acid), phenol, resorcinol, hydroxy hydroquinone, and phloroglucinol. Algal assays confirmed growth inhibition of M. aeruginosa by polyphenols, i.e., caffeic/protocatechuic acid, catechol, hydroquinone, hydroxy hydroquinone, and phloroglucinol, and by phenols containing methoxy groups, i.e., vanillic, sinapic, and syringic acids. Accordingly, this indicates good feasibility for controlling growth of M. aeruginosa using such plant-producing polyphenols and/or phenols as additives. A comparison of the inhibitory effects of the polyphenols showed that those induced by polyphenols in which phenolic hydroxy groups bound a benzene ring at ortho- and/or para-positions to another phenolic hydroxy group are stronger than the effects induced by polyphenols in which phenolic hydroxy groups are at only meta-positions. Experiments showed that the only polyphenols demonstrating significant growth inhibition of M. aeruginosa were autoxidized. These results suggest that autoxidation of the polyphenols induces inhibitory effects by producing polyphenol-autoxidized products such as radicals. 相似文献
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在虹桥综合交通枢纽市政配套工程3标工程PHC管桩质量监理控制中,严格按照监理程序与方法,采取相应措施,综合运用超声探伤、低应变检测、高应变检测、静载试验检测等多种检测技术,保证了桩身完整性和承载力。事实证明,运用这些检测技术,对提高监理、施工质量、完善设计和节约工程投资等方面都起到明显效果,取得良好效益。 相似文献