氯氧镁水泥纤维复合材料在混凝土加固中的应用前景

简介氯氧镁水泥的性能和改性方法 ,探讨研发耐火和耐久性能优越的氯氧镁水泥纤维复合材料加固混凝土的可行性     

秸秆-氯氧镁水泥复合材料制备研究

以秸秆为填充材料,氯氧镁水泥为胶结材料,掺加适当比例的矿物掺和料和外加剂,并采用加压锁模工艺,制成秸秆-氯氧镁水泥复合材料(straw-magnesite oxychloride cement composites,SMOCC,以下简称秸秆复合材).首先探究了秸秆种类、长度和含水率(质量分数,下同)对秸秆复合材性能的影响,再通过正交试验,确定秸秆掺量、氯氧镁水泥配合比和砂掺量这3个因素对秸秆复合材抗压强度的影响,最后研究了最优配方情况下秸秆复合材干密度与其抗压强度的关系.结果表明:在秸秆含水率≤10%,氯化镁溶液波美度为23°Bé,养护龄期为28d的条件下,氯氧镁水泥配合比相同且采用加压锁模工艺时,秸秆种类对秸秆复合材抗压强度影响不明显;在秸秆长度改变的情况下,采用小麦秸秆比采用玉米秸秆制备的秸秆复合材性能更加稳定,且秸秆长度为100mm时,其抗压强度最高;正交试验中3个因素对秸秆复合材抗压强度影响程度依次为:氯氧镁水泥配合比、秸秆掺量、砂掺量;在一定范围内,秸秆复合材抗压强度随其干密度的增加而线性增大.     

纤维粉煤灰氯氧镁水泥

本文叙述了不同种类的外加剂和不同的加入量对粉煤灰作填料的氯氧镁水泥抗折强度和浸水稳定性的影响，讨论了玻璃纤维、稻壳加入量及成型方法对抗折强度的影响。     

耐水氯氧镁水泥/玻璃纤维复合材料的研制

通过添加外加剂,对氯氧镁水泥进行改性,制备耐水氯氧镁水泥/玻璃纤维复合材料,实验结果表明:单一外加剂在氯氧镁水泥中有最佳掺量;磷酸的加入,可以增加氯氧镁水泥/玻璃纤维复合材料的耐水性能;减水剂与FeSO4的交互作用显著,当减水剂用量为0.25%、FeSO4用量为1.5%时复合材料的强度最高,耐水性能良好;通过外加剂的复配,可以制备耐水的氯氧镁水泥/玻璃纤维复合材料。     

杜拉纤维改性氯氧镁水泥耐水性的初探

通过试验研究,找到氯氧镁水泥的基本合理配方;再加入杜拉纤维,着重探讨杜拉纤维对氯氧镁水泥强度和耐水性的影响。     

氯氧镁水泥的性能和使用价值

以苛性氧化镁(俗称轻烧镁粉或菱苦土)和氯化镁(俗称卤粉、卤片等)或硫酸镁为主要原料,加水调制成的一种胶凝材料,是法国人索瑞尔(Sorel)在1867年发明的,故称为索瑞尔水泥,也叫氯氧镁水泥、氧氯化镁水泥或硫氧镁水泥、氧硫化镁水泥,国内俗称菱苦土水泥。作者经过近几年来的试验研究和生产实践,对这种水泥的物理化学力学性能,有了一些粗浅的认识,现简介如下:     

氯氧镁水泥耐久性研究

通过对活性无机填料的适当选择和配合,并优选磷酸盐类添加剂和氟系扩散剂,制成复合防水剂,进而得到综合性能较好的改性镁水泥。ＸＲＤ分析和ＳＥＭ观察表明,在改性镁水泥的硬化体中,Ｍｇ２Ｐ２Ｏ７和ＡｌＰＯ４等不定形凝胶状耐水相包容着５·１·８相［５Ｍｇ（ＯＨ）２·ＭｇＣｌ２·８Ｈ２Ｏ］,并填充孔隙,使改性镁水泥的耐水性明显提高。大气暴露试验表明,试样表面光洁、无粉化和明显的返卤返霜现象,体积安定性、耐候性、耐干湿交替性均优良。     

轻质稻草秸秆纤维水泥基实心砖的性能试验研究

利用农作物稻草秸秆材料与水泥制备出综合性能良好的稻草秸秆纤维水泥基实心砖(Rice straw fiber-cementitious solid brick,RSFCB),分析了实心砖的力学性能,并将其与按C30配合比生产的普通混凝土实心砖(General soild concrete brick,GCB)的力学性能和物理性能进行对比,结果表明,试验研制的稻草秸秆水泥基砖满足非承重墙墙体材料的强度要求,且具有轻质、保温隔热、绿色环保的特点,为稻草秸秆的应用提供了新的方向。     

Strengthening of structures using carbon fibre/epoxy composites

Innovations in manufacturing and new technologies are based upon new materials and upon new applications which use materials already employed in other industries. This paper shows how high-performance fibre-reinforced composites, utilized for the last 25 years by the aircraft and space industries, may be employed to strengthen existing structures for civil engineering purposes.     

PMMA/MWNT复合材料燃烧特性

以甲基丙烯酸甲酯(MMA)为原料,多壁碳纳米管(MWNT)为阻燃剂,采用原位聚合的方法制备了聚甲基丙烯酸甲酯/多壁碳纳米管复合材料。使用不同辐射强度的锥形量热仪和UL94分级测试,研究了复合材料的燃烧特性。锥形量热仪测试结果表明,50kW/m2辐射强度下,加入1.0%碳纳米管的PMMA复合材料热释放速率峰值降低幅度最大;高辐射强度下,碳纳米管对PMMA复合材料燃烧特性的影响减弱。UL94分级测试结果表明,碳纳米管的添加可以抑制PMMA复合材料的熔滴行为。     

建设部绿色建筑工程技术研究中心

2005年,经国家建设部授权,建设部绿色建筑工程技术研究中心（以下简称“中心”）依托上海市建筑科学研究院正式组建成立。中心的建设目标是针对绿色建筑的关键技术研发、技术体系集成创新．实验平台搭建．示范工程建设．适用技术应用推广、国家标准规范编制研究．国内外合作交流、绿色建筑理念传播和教育培训等方面开展工作,成为建设部绿色建筑工程技术的研发中心、     

石膏砌块墙体的稳定性研究(一)

以石膏砌块代替传统墙体材料，在大中型框架建筑结构中作内隔墙，研究石膏砌块墙体的建筑稳定性。介绍了建筑石膏、石膏砌筑粘结剂的选择，砌筑中防水基层的处理、墙面最大极限尺寸及砌筑施工质量等对墙体整体性能的影响。研究了石膏块受大气与潮湿环境影响、石膏砌块墙体受地震影响与火灾影响时建筑墙体的安全与稳定性。     

Rheological properties and storage stability of bitumen/SBS/montmorillonite composites

Styrene–Butadiene–Styrene triblock copolymer is commonly used for modifying physical, mechanical and rheological properties of bitumen. Because of the poor compatibility between SBS and bitumen, SBS modified bitumen is not storage stable at high temperature. To obtain more compatibility between SBS and bitumen, several methods have been suggested. In this study, organophilic montmorillonite/SBS modified bitumen mixtures were prepared by melt intercalated blending. Physical and rheological properties of polymer modified bitumen were compared before and after adding nanoclay to the bitumen. Results showed that the presence of nanoclay improves the storage stability of PMB significantly without adverse effect on other properties of it. The structure of OMMT/SBS/bitumen blend was characterized by XRD. The spectra indicated that proper dispersion of OMMT in SBS led to a homogenous blend which is named exfoliated structure. The result of storage stability test showed that the difference in softening point was in good accordance with ASTM standard limitation which means that OMMT can improve the storage stability of PMB. Also morphological analysis confirmed storage stability results.     

水性环氧乳液改性水泥复合材料的力学性能研究

采用研制的非离子型水性环氧乳液与水泥共混,制备高强度水性环氧乳液改性水泥复合材料。分别测试不同养护条件下水性环氧乳液对复合材料力学性能的影响。结果表明,水性环氧乳液能提高复合材料的抗压、冲击、弯曲强度及其韧性,同时可以降低复合材料的吸水率、提高耐腐蚀性。对水性环氧与水泥共混的机理进行了分析和模拟。     

建设部办公楼抗震加固及装修改造工程

建设部办公楼是50年代建成的近代保护性建筑，对其进行全面的抗震加固及机电、装修改造，在既有建筑加固改造工程中具有代表性。通过该工程，总结既有建筑抗震加固及装修改造工程的特点及施工技术、管理要点。     

推广植物纤维轻质隔墙板的思考

植物纤维轻质隔墙板产品是一个被列入国家星火计划的新兴墙材生产项目,它是以植物秸秆为主要原料,配以粘合剂、阻燃剂及其他化工原料为辅料研制生产的轻质隔墙条板,现已被国家科技部、国家税务总局、国家质量监督总局、国家环保总局共同认证为重点推广的绿色环保产品.     

Form finding methodology for force-modelled anticlastic shells in glass fibre textile reinforced cement composites

The reinforcement of a specifically developed fine grained cement matrix with glass fibre textiles in high fibre volume fractions creates a fire safe composite that has-besides its usual compressive strength-an important tensile capacity and omits the need for any steel reinforcement. Strongly curved shells made of textile reinforced cement composites (TRC) can cover medium (up to 15 m) span spaces with three times smaller shell thicknesses than conventional steel-reinforced concrete shells. This paper presents a methodology to generate force-modelled anticlastic shell shapes that exploit both the tensile and compressive load carrying capacities of TRC. The force-modelling is based on the dynamic relaxation form finding method developed for gravity (in this case self-weight) loaded systems. The potential of the presented methodology to develop structurally sound anticlastic shell shapes is illustrated by four case studies.     

Tensile strain hardening behaviour of hybrid steel-polyethylene fibre reinforced cementitious composites

Tensile strain hardening and multiple cracking behaviours of fibre reinforced cementitious composites containing different hybrid combinations of steel (ST) and polyethylene (PE) fibres are reported. Various hybrid combinations of ST and PE fibres of 12 mm length are studied. Different hybrid combinations of ST and PE fibres of 18 mm length are also studied here. The effects of addition of different types of sands of different contents on the strain hardening behaviour are also evaluated. PE fibres are found to improve the tensile strain capacity of hybrid fibre composites whereas ST fibres contributed on the improvement of ultimate tensile strength of hybrid fibre composites. By increasing the length of PE fibres by 1.5 times significant increase in tensile strain capacity as well as improvement in strain hardening and multiple cracking behaviour of hybrid fibre composites is observed. The addition of sand adversely affected the strain hardening and multiple cracking behaviour of hybrid fibre composites with reduction in tensile strain capacity.