PVC/FRP复合给水管的应用

本文介绍了国内外应用给水PVC管和玻璃钢（FRP）管的情况，推出能把各自优点揉合在一起的PVC／FRP复合管，可供设计市政供配水管网或长距离输水干管的同行参考。     

具有高压剪强度的PVC/FRP复合管道界面粘结剂

硬质聚氯乙烯(PVC)具有良好的耐腐蚀性能,致密耐磨,价格低廉,在化工防腐领域得到广泛应用。但是,由于PVC固有的缺点,如机械强度低、使用温度不高、易老化等,从而限制了PVC在工业上的应用。 以硬质PVC塑料管作内衬,外缠玻璃钢(FRP)增强的PVC/FRP复合结构管道,克服了PVC塑料管使用温度低和机械强度低的缺点,充分发挥了玻璃钢高强度的性能,使PVC/FRP复合管具有重量轻、强度高、抗冲击、耐磨及优良的耐腐蚀性能和良好的水力学特性,是     

国产化的铝塑复合管性能测试结果与分析

铝塑复合管是继聚氯乙烯(PVC)管、聚乙烯(PE)管、聚丙烯(PP)管、聚丁烯(PB-1)管、交联聚乙烯(PEX)管之后,八十年代末欧美国家推广的新型管道。 国家化学建材测试中心建工测试部是受国家委托,对用于建筑的门窗、涂料、供水、供暖、供气各种成品化学建材进行测试。九十年代中期,我们曾对进口的各种塑料管道和铝塑复合管进行过检测。当时铝塑复合管主要都是德国、韩国和台湾省进口产品     

PVC／FRP复合给水管的应用

本文介绍了国内外应用给水PVC管和玻璃钢(FRP)管的情况，推出能把各自优点揉合在一起的PVC/FRP复合管，可供设计市政供配水管网或长距离输水干管的同行参考。     

塑料管材在民用建筑的应用

目前工程应用的塑料管按材料分为：硬聚氯乙烯(PVC—U)管，软聚氯乙烯(SPVC)管，氯化聚乙烯(CPVC)管，增强复合聚氯乙烯管，高密度聚乙烯(HDPE)管、中密度聚乙烯(MDPE)管、低密度聚乙烯(CDPE)管、交联聚乙烯(PEX)管、铝塑复合(MP)管、聚丙烯(PP)管、共聚改性聚丙烯(PPC)管、三型聚内烯(PP—R)管、聚丁烯(PB)管、实壁(ABS)管、玻璃钢(FPR)管等等。     

建筑工程给排水常用管材的特点及应用分析

塑料管是合成树脂加添加剂经熔融成型加工而成的制品。常用塑料管有：硬聚氯乙烯管（PVC—U），氯化聚氯乙烯管（PVC—C）。高密度度聚乙烯管（HDPE），交联聚乙烯管（PE—X），无规共聚聚丙烯管（PP-R），聚丁烯管（PB），工程塑料丙烯晴-丁二烯-苯乙烯共聚物（ABS）等。     

热塑性塑料管应用技术（1）

1热塑性塑料管特性与制造工艺1．1热塑性塑料的品种与特点热塑性塑料为线型分子结构，因其温度升高时变软，温度降低时变硬，故称为热塑性。热塑性塑料的品种众多，差异较大。主要品种有聚氯乙烯（PVC）、聚乙烯（PE）、聚苯乙烯（PS）及聚丙烯（PP）。本讲座文将重点介绍供制造输水管路的硬聚氯乙烯（PVC－U）塑料管及输送燃气用的中、高密度聚乙烯（MDPE、HDPE）塑料管。1．1．1聚氯乙烯（PVC）塑料制造聚氯乙烯塑料的主要原料是聚氯乙烯树脂，由氯乙烯单体经悬浮法工艺聚合而成。利用悬浮法工艺制造的聚氯乙烯树脂粒径较大，制…     

FRP/PVC高压输浆复合管试制成功

一种用纤维缠绕法生产的大口径 FRP/PVC 高压复合管最近在江西九江玻璃钢制品厂试制成功,并于1990年11月通过了省级鉴定。化工管道的防腐过去曾使用不锈钢管、衬胶钢管、玻璃钢管以及各种塑料管道,但这些管道都不同时具备耐压、耐磨、耐腐蚀及价格低的优点,而FRP/PVC 复合管具有优良的耐腐、耐磨性能,且其抗压能力大幅度提高,工作压力提高到1.6MPa,     

新型管材的优化选用

介绍了新型管材硬聚氯乙烯(UPVC)管，聚乙烯(PE)管，交联聚乙烯(PEX)管，聚丙烯类(PP)管，铝塑复合管，聚丁烯(PB)管等管材的相对比使用情况，以及该类管材在实际工程中使用的优劣对比情况，从而给新型塑料管材管件在实际工程中的使用起到一定的指导作用。     

新型塑料给水管材的性能和应用

介绍了在国内新型建筑给水管材中占主导地位的铝塑复合管、交联聚乙烯（PE－X）管、三型无规共聚聚丙烯（PP－R）管的发展,生产工艺和性能特点等。提出了目前新型建筑给水管材市场及推广应用中存在的问题及建议。     

An alternative method for fire smoke toxicity assessment using human lung cells

An alternative method for fire smoke toxicity testing using human lung cells has been investigated. A laboratory-scale vertical tube furnace was used for the generation of combustion products. Experiments were conducted under isothermal oxidative non-flaming conditions. A range of building and train interiors including polyethylene (PE), polypropylene (PP), polycarbonate (PC), polyvinyl chloride (PVC), fiberglass reinforced polymer (FRP), and melamine-faced plywood (MFP) were studied. The exposure of combustion toxicants to human lung cells (A549) at the air/liquid interface was acquired using a Harvard Navicyte Chamber. Cytotoxic effects on human cells were assessed based on cell viability using the MTS assay (Promega). Cytotoxicity results were expressed as NOAEC (No Observable Adverse Effect Concentration), IC₁₀ (10% inhibitory concentration), IC₅₀ (50% inhibitory concentration) and total lethal concentration (TLC) values (mg/L). These cytotoxicity results were compared to published combustion toxicity data. Mass loss data and toxic product yield were also determined. The following toxicity ranking was observed from the most toxic to the least toxic: PVC>PE>PP> FRP-10>PC> FRP-16>MFP. The method described here could potentially be an alternative to current fire toxicity standard test methods.     

烧结砖脱硫塔及厂房火灾认识和分析

烧结砖企业要避免脱硫塔系统内防腐层、喷淋层、喷嘴和除雾器、PP材料和管道、玻璃钢屋面瓦等材料发生火灾,应加强辨识热烟气介质着火源的特殊性,防止烟气介质温度超过玻璃钢制品的工作温度限制,防止高温烟气介质成为着火源,与玻璃钢挥发可燃性气体、空气相互作用达到燃烧条件.     

ECC梁的力学性能试验研究

研究了PP ECC梁的四点弯曲试验性能,制作了钢筋增强PP ECC梁,钢绞线GFRP筋增强PPECC梁,素PP ECC梁和普通钢筋混凝土梁4组试件。在试验研究中,主要考虑了配筋率、龄期等参数,对比了钢筋增强PP ECC梁、钢绞线GFRP筋增强PP ECC梁、素ECC梁与普通钢筋混凝土梁的弯曲性能,测试了试件的开裂荷载、裂缝的开展、各级荷载下的应变以及试件的极限荷载,验证了平截面假定。结果表明,对不同配筋率的PP ECC梁,配筋率越大,极限承载力增加,但极限变形减小,裂缝宽度的变化不明显。同一配筋率下,PP ECC梁比普通钢筋混凝土梁具有更高的承载力和变形性能,在屈服时刻裂缝宽度可控制在0.1mm以内。     

FRP加固钢筋混凝土桥墩基于性能的指标量化

将基于性能设计的思想与FRP加固钢筋混凝土桥墩相结合,对国内外98个FRP加固钢筋混凝土桥墩试件的位移角进行统计分析,给出了划分性能水平的位移角限值。对FRP加固钢筋混凝土桥墩的屈服位移角dy和极限位移角du进行单因素分析。讨论了位移角与纵筋率ρs、体积配筋率ρv、混凝土强度fc、轴压比n、剪跨比λ、及FRP特征值λf之间的关系,将显著影响位移角的因素:纵筋率ρs、轴压比n、FRP特征值λf考虑到量化当中,并给出修正公式。     

HB FRP加固混凝土结构组合界面黏结特性

为揭示HB-FRP(hybrid bonded fiber reinforced polymer)加固混凝土结构多作用组合工作机制,设计了5组黏结作用组合试验.基于实测荷载-滑移关系、应变分布、黏结-滑移关系开展了界面黏结特性研究,提出组合界面黏结-滑移统一模型和黏结荷载表达式.结果表明:HB-FRP加固混凝土组合作用可拆分为FRP黏结混凝土、侧压力和FRP黏结钢板;组合界面的黏结应力发展不同步,FRP板下表面与混凝土的剥离早于FRP板上表面与钢板的剥离,叠合工作时序不同;由侧压力引起的界面摩擦应力随界面应力的发展而增加并趋于稳定;理论模型结果与试验结果具有较好的一致性,可用于计算组合界面的黏结荷载.     

Comparison of the equilibrium sorption of five organic compounds to HDPE, PP, and PVC geomembranes

This experimental investigation quantified the sorption uptake of five commonly encountered organic groundwater contaminants, methyl tertiary-butyl-ether (MTBE), benzene, trichloroethylene (TCE), 1,2-dichorobenzene (1,2-DCB), and trinitrotoluene (TNT), to geomembranes made from high density polyethylene (HDPE), polypropylene (PP), and polyvinylchloride (PVC). The organic compounds were chosen to span a range of aqueous solubilities and chemical properties. The geomembranes tested in this study exhibited sorption capacities that were of similar magnitude for each of the contaminants tested, with the exception of 1,2-DCB to HDPE, which exhibited strong uptake in comparison to the other solute/sorbent combinations. In general, the PVC geomembrane demonstrated the highest sorption capacities, while the HDPE geomembrane demonstrated the lowest sorption capacities. Measured partitioning coefficients for the contaminant/geomembrane combinations ranged from S_gf<1 to 160, but most commonly had values between 10 and 75.     

Strengthening of two-way concrete slabs with FRP composite laminates

This paper presents an experimental and analytical investigation for evaluating the ultimate response of unreinforced and reinforced concrete slabs repaired and retrofitted with fiber reinforced polymer (FRP) composite strips. A uniformly distributed pressure was applied to several two-way large-scale slab specimens using a high-pressure water bag. Both carbon/epoxy and E-glass/epoxy composite systems were used in this study. In predicting the behavior of the repaired slabs, the finite element method was used. Comparison between the experimental and the analytical results indicated the validity of the computational models in capturing the experimentally determined results for both the control and the rehabilitated slabs. For repair applications, test results indicated that both FRP systems were effective in appreciably increasing the strength of the repaired slabs to approximately five times that of the as-built slabs. For retrofitting applications, use of FRP systems resulted in appreciable upgrade of the structural capacity of the as-built slabs up to 500% for unreinforced specimens and 200% for steel reinforced specimens.     

Application of improved hybrid bonded FRP technique to FRP debonding prevention

External bonding of fiber reinforced polymer (FRP) is one of the most efficient techniques for retrofitting and strengthening concrete structures. However, the bond interface is the weakest link in such retrofitted or strengthened concrete members, resulting in premature FRP debonding. Therefore, a newly improved hybrid bonded FRP (IHB-FRP) technique is developed in this paper for strengthening concrete members. Unlike the conventional mechanical fastening method, the mechanical fasteners in the technique do not penetrate the FRP strips and the capping plates serve to apply vertical pressure to the FRP strips. An experimental study on the flexural strength of IHB-FRP technique strengthened beams is conducted. It is found that all the beams strengthened with the IHB-FRP technique fail due to tensile rupture of FRP strips even for seven plies of FRP strips. Based on the experimental results, the effects of the steel reinforcement ratio, the number of FRP plies, and the fastener spacing on the ultimate load are evaluated. Finally, a simplified method is proposed for estimating the ultimate bending moment of the IHB-FRP strengthened beam. The validity of the method is verified with the experimental results.     

关于改善纤维布加固混凝土梁抗弯性能方法的讨论

简述加固混凝土梁纤维复合材料 (FRP)性能发挥效率较差、加固梁延性较低的主要原因 ,说明提高FRP性能的利用率、改善加固梁延性的途径是 :梁端FRP锚固、沿梁长粘结加压和使用混杂纤维复合材料 (HFRP) ;并初步探讨简易实施方法。     

Determination of geomembrane – protective geotextile friction angle: An insight into the shear rate effect

This study investigates how the shear rate can affect the geomembrane – protective geotextile friction angle. Four types of geomembranes (GMB) were considered (EPDM, HPDE, PP, and PVC) and a single nonwoven needle-punched geotextile (GTX_nw) was used to make the interfaces with the geomembrane. Three shear devices were used: a large-scale inclined plane (IP), a shear box (SB), and a small-scale shear device (ssSD). The ssSD allows two shear modes to be compared: one mode involves incrementally increasing the shear stress, and the other involves imposing a constant tangential velocity at the interface. Only the PP GMB- GTX_nw was tested with the SB and the ssSD. Inclined plane standardised tests show that for the three interfaces that undergoes gradual sliding (EPDM, PP and PVC GMB- GTX_nw), it is shown that a step-by-step experimental procedure gives significantly lower interface friction angle than that given by the procedure from the current international standard, which is explained by the increase of interface shear stress with sliding speed. These observations are confirmed by shear box tests. One major practical result is that, following the nature of geosynthetics, the shear rate applied in large-scale shear box tests should be adapted to assess a safety value of a geosynthetic - geosynthetic interface friction angle.