Super-absorbent swellable polymer as grouting material for treatment of karst water inrush

Grouting is the most commonly used method to control water inrush in underground engineering.Traditional cement-based materials are easy to dilute and hard to coagulate under the influence of large flow and high-velocity water inrush. To address these deficiencies, a new type of polymer grouting material with an excellent expansion ratio was synthesised. The material quickly absorbs water and has an expansion ratio of 1:300. The material is composed of a superabsorbent polymer(SAP), glycerol, and ethanol. The effects of water quality on the expansion ratio and expansion rate of the material were examined, and the best solid–liquid ratio for the slurry was determined by fluidity measurements. A karst specially designed pipeline water inrush test device showed that 800 g of SAP can achieve 0.6 m/s water flow blockage in the smooth pipeline, demonstrating that the ability of the SAP slurry to block water inrush is superior to those of other materials. This study provides a reference for water inrush plugging,and has important implications for the reduction and control of karst pipeline-type water inrush disasters, ensuring the safety of construction sites and preventing loss of life and damage to property.     

HSGM-A高强微膨胀灌浆料在王滩电厂工程中的应用

通过火电厂大型设备安装的二次灌浆施工为例,详细介绍了灌浆材料的施工技术要求及各种性能,有效保证了各种设备安装质量.     

聚合物-水泥基注浆材料早期流变及水化特性

为制备满足复杂地层加固工程需求的高性能水泥基注浆材料,探究以偏铝酸钠(SA)、聚羧酸(Sp)及高吸水性树脂(SAP)为组分的聚合物体系及其掺量对新拌水泥浆体流变特性与泌水率的影响,并采用水化放热监测与倒置荧光显微技术,对不同体系下水泥浆体早期水化进程及微米级颗粒的悬浮分散形态进行分析.结果表明:新拌水泥浆液流动性和泌水率与SA、SAP掺量呈负相关,随Sp掺量增加而提高. Sp及SAP延缓了水泥早期水化进程,改性样延迟近1 h进入水化诱导期,诱导期内水化放热速率显著降低.在不同掺量SA的促凝效应、Sp的分散效应以及SAP的"水库"作用下,新拌水泥浆液表现为初始及经时流动度大于200 mm的高流态期可分别被控制在10、20、30 min内且析水率小于5%(稳定性浆液),接近临界期时流动度陡降、流变参数突增并迅速凝结的流变特性.结合微观结构观测结果,建立了新拌水泥浆体流变演化模型,揭示多聚合物协调效应下水泥浆体呈现分散-储水-流变-水化的早期流变机制.     

水泥-粉煤灰注浆材料的研发与应用

为解决矿山煤层底板承压水威胁区域的加固问题,从不同粉煤灰掺量、不同水灰比、不同固相质量比的硬化体强度、浆体凝结时间和黏度之间的相互关系,对粉煤灰注浆材料进行了系统的研究,提出了具有早强性和可注特点的复配方案,采用活化粉煤灰(其组分质量百分比为粉煤灰∶生石灰∶元明粉=76.22∶22.26∶1.52)作为注浆掺合料,另加入早强剂,配制出新型水泥——粉煤灰注浆材料.通过工程的实际应用表明,该注浆材料不仅符合现行注浆材料检验标准,而且很好地满足了煤层底板注浆加固堵水的要求.     

不同温度下复合材料弯曲性能的研究进展

复合材料应用于不同领域时,对其在不同温度下的弯曲性能要求也有所不同.对近年来聚合物基复合材料、陶瓷基复合材料、碳基复合材料和金属基复合材料在不同温度下弯曲性能的研究状况进行了总结和评述,对不同基体复合材料在不同温度下的弯曲性能差异进行了探讨,并指出应进一步完善高温下复合材料弯曲性能的测试方法,根据其破坏模式建立理论模型以便进行有效的模拟和数值分析.     

Compressive strength development and microstructure of cement-asphalt mortar

The compressive strength developing process and the microstructure of cement-asphalt mortar (CA mortar) were investigated. The fluidity of CA mortar has a great influence on its strength. The optimum value of spread diameter of slump flow test is in the range of 300 to 400 mm. The compressive strength of CA mortar keeps a relatively high growth rate in 56 days and grows slowly afterwards. The residual water of hydration in CA mortar freezes under minus environmental temperature which can lead to a significant reduction of the strength of CA mortar. Increasing A/C retards asphalt emulsion splitting and thus prolongs the setting process of CA mortar. The hydration products of cement form the major structural framework of hardened CA mortar and asphalt is a weak phase in the framework but improves the viscoelastic behavior of CA mortar. Therefore, asphalt emulsion should be used as much as possible on the condition that essential performance criterions of CA mortar are satisfied.     

浆液性质对注浆压力及扩散方式的影响规律

为研究浆液性质对于注浆压力及浆液扩散模式的影响规律,设计了注浆扩散模拟试验系统。该系统通过采用整体填土压实,相比常规人工分层填土压实,可有效避免土体内部层间界面的产生,从而避免层间界面对于浆液扩散的影响。通过上述注浆扩散模拟试验系统开展了羧甲基纤维素钠浆液(模拟渗透注浆)、水泥单液及水泥-水玻璃浆液的土体注浆试验,分析注浆压力及浆液扩散特征,并针对注浆压力进行理论分析验证。研究结果表明:浆液性质对于注浆压力增长及劈裂特征点具有显著影响,通过分析注浆压力增长趋势及劈裂特征点特征可判定浆液扩散模式。     

Shrinkage Behavior of High Performance Concrete at Different Elevated Temperatures under Different Sealing Conditions

The shrinkage behavior of high performance cement concrete made from Portland cement, ultra fine granulated blast furnace slag and pulverized fly ash with addition of superplasticizer at different temperatures from ambient temperature to 120 ℃ under different seuliug conditions was investigated by means of length change measurement on cylindrical concrete specimens along with curing age. Results show that drying shrinkage deformations of titled concrete specimens increased rapidly as the curing temperature rose. The development of dryiing shrinkage deformatian can be efficiently controlled with the aid of aluminum tape sealing as compared with the unsealed specimens, especially when the curing temperature is below 60℃ , although it will increase dramatically when the curing temperature is elevated to above 90%＂ . Polymer coating on concrete specimens showed a similar effect on the control of drying shrinkage as the sealing operation with aluminum tape.     

Strength of copolymer grouting material based on orthogonal experiment

Using the orthogonal experimental design method involving three factors and three levels, the flexural strength and the compressive strength of copolymer grouting material were studied with different compositions of water-cement ratio (mass fraction of water to cement), epoxy resin content, and waterborne epoxy curing agent content. By orthogonal range and variance analysis, the orders of three factors to influence the strength, the significance levels of different factors, and the optimized compound ratio scheme of copolymer grouting material mixture at different curing ages were determined. An empirical relationship among the strength of copolymer grouting material, the water-cement ratio, the epoxy resin content, and the waterborne epoxy curing agent content was established by multivariate regression analysis. The results indicate that water-cement ratio is the most principal and significant influencing factor on the strength. Epoxy resin content and waterborne epoxy curing agent content also have a significant influence on the strength. But epoxy resin content has a greater influence on the 7-day and 28-day flexural strength, and waterborne epoxy curing agent content has a greater influence on the 3-day flexural strength and the compressive strength. The copolymer grouting material with water-cement ratio of 0.4, epoxy resin content of 8% (mass fraction) and waterborne epoxy curing agent content of 2% (mass fraction) is the best one for repairing of cement concrete pavement. The flexural strength and the compressive strength have good correlation, and the ratio of compressive strength to flexural strength is between 1.0 and 3.3. Foundation item: Projects(40728003, 40772180, 40802064) supported by the National Natural Science Foundation of China; Project (07JJ4012) supported by the Hunan Provincial Natural Science Foundation of China; Project(20080430680) supported by China Postdoctoral Science Foundation; Project(B308) supported by Shanghai Leading Academic Discipline Project     

温度作用下封装材料厚度变化对翘曲影响

主要研究在均匀温度载荷和不均匀温度载荷作用下材料厚度变化对翘曲的影响。研究表明，封装结构各种材料的不同，温度的分布也不同，翘曲的方向和数值也不同，而且均匀温度载荷作用下尺寸变化对翘曲的影响明显比不均匀温度载荷作用下的大。     

Reaction products of MgO and microsilica cementitious materials at different temperatures

The paste was prepared by mixing MgO, microsilica and H2O in the presence of water reducer at different reaction ratios and temperatures, and characterized by XRD, DTA, TGA, IR, and solid-state 29Si NMR. The experimental results showed that, besides Mg(OH)2, magnesium silicate hydrate (M-S-H) was formed at a low temperature such as 25 and 50 ℃. At a high temperature of 100 ℃, Mg(OH)2 can be further transformed into M-S-H completely, for instance, within ca. 1 month in an excess of microsilica. The average composition and structure of M-S-H was mainly related to the reaction mixture and curing temperature and was discussed in detail.     

不同强度等级再生混凝土抗折性能的研究

为研究不同强度等级再生混凝土的抗折性能,设计了C30,C40,C50三个强度等级的再生混凝土,并对其抗折强度、抗压强度进行试验研究.试验结果表明:同一强度等级,再生混凝土可以达到甚至超过普通混凝土的抗折强度,再生混凝土的抗折强度与立方体抗压强度比值与普通混凝土接近;随着混凝土强度等级的升高,其抗折强度与立方体抗压强度的比值逐渐减小.     

镍基单晶高温合金不同温度下的拉伸性能

为了研究一种镍基单晶高温合金从室温到1100℃范围的拉伸变形与断裂行为,利用扫描电子显微镜和透射电子显微镜对拉伸断口及变形后位错组态进行观察和分析.结果表明：合金的屈服和抗拉强度均在约800℃时达到峰值,而塑性与强度的变化规律基本相反.室温和中温拉伸条件下,断口表现为解理断裂;而高温时则为微孔聚集型断裂.室温拉伸条件下,合金的主要变形方式为单根位错剪切γ′相;高温下为位错绕过γ′相;中温下则表现为由剪切到绕过的过渡.     

超低温下层合板复合材料的短梁法层间剪切强度研究

采用三维有限元法对超低温下玻璃纤维强化树脂层合板的短梁法层间剪切强度进行了研究,通过与二维有限元解析结果的对比,分析了试验片三维形状对中性面上剪切应力分布的影响;通过三维有限元解析,阐明 了剪切领域内的剪切应力分布。数值解析结果表明,短梁剪切试验片的最大剪切应力并非在中性面上产生,靠近载荷点及支点附近产生较大的局部剪切应力;中性面上的剪切应力分布不均匀,但中性面上最大剪切应力均匀分布的范围较大;基于梁理论的表观层间剪切强度较中性面上的最大剪切应力值低,采用短梁剪切试验法时会产生较小的强度评价。     

钢渣双液注浆材料的研究

钢渣与矿渣、粉煤灰复掺作为注浆材料使用,既优化了骨料的级配又最大限度地使用了工业废渣.基于水玻璃碱激发工业废渣的原理,研究出以钢渣为主最佳配合比的工业废渣-水玻璃双液注浆材料.研究表明,随着水玻璃掺量的增加注浆材料的凝胶时间增加而结石体强度先增加后减小;钢渣与矿渣、粉煤灰两两复掺时前者的效果最好;三种工业废渣三掺(钢渣∶矿渣∶粉煤灰=2∶3∶1)时,注浆材料的强度最大,28 d抗压强度达14 MPa.     

不同温度下GS0202菌产酶差异的研究

利用电泳法及DEAE-Cellulose DE-52离子交换柱层析法对Arthrobacter chloropHenolicusGS0202菌分别在20和60℃下培养时产两种不同的酶进行研究。结果表明,20℃下培养所产的酶能水解人参皂苷Rb1生成人参皂苷F2,60℃下培养所产的酶能水解人参皂苷Rb1生成人参皂苷Rg3;找到了4条差异蛋白带,它们的分子质量分别约为66、47、35、22 ku;将60℃下培养得到的酶分离提纯,其纯酶的分子质量经电泳鉴定约为66 ku,与1号差异带的分子质量吻合。     

Tensile and compression properties of Zr-based bulk amorphous alloy at different temperatures

Since the discovery of the Au-Si metallic amorphous alloy ribbon in 1960 by Duwez and co-workers[1] by rapid quenching, rapid developments have been obtained on the preparation of the amorphous alloy with the rapid quenching technique. However, from 1960 to 1989, the amorphous alloy could be only produced into forms of ribbon, flake, wire and powder due to the limitation of the cooling rate (>105 K/s). In the late 1980s, the Inoue group at Tohoku University in Sendai, Japan, investigated th…     

不同温度下可溶有机质对煤电阻率的影响

煤中可溶有机质能改变煤的孔隙结构,进而影响煤的电阻率,为得到煤中存在的可溶有机质对煤电阻率的影响规律,选取3种不同变质程度的60～80目的原煤煤粒,采用乙酸乙酯作为溶剂来萃取煤中可溶有机质,萃取时间取4、8、12、16、20、24 h,将萃取前后的煤粒制成型煤,在10℃～90℃温度条件下,利用CHI660E型电化学工作站测试煤样的I-V曲线,并计算出电阻率,分析和研究不同温度下煤电阻率受可溶有机质的影响机理和规律.结果表明:在10℃～90℃温度范围内和萃取时间为0～24 h时,煤中可溶有机质的存在可明显提高煤电阻率1.31～1.74倍,煤电阻率随萃取时间的增大(煤中可溶有机质含量减少)的变化符合Sigmoid函数关系,且只会在一定的区间内变化;煤电阻率随温度的升高呈现抛物线规律,萃取前后煤电阻率的比值随温度的升高近似呈现Lorentzian函数分布,在40℃～50℃时出现拐点;可溶有机质对煤电阻率影响的敏感性和相关性随煤变质程度的提高而逐渐减弱.     

不同温度下AZ31镁合金绝热剪切变形局域化

为了了解镁合金在不同温度高应变率载荷作用下发生变形局域化的特点,进而揭示镁合金在高速冲击载荷作用下发生绝热剪切的特殊规律,采用分离式Hopkinson压杆对挤压态AZ31镁合金进行了常温及高温的高速冲击压缩试验,而后对不同温度冲击后的试样通过光学显微镜、扫描电镜和透射电镜进行变形机制的分析.结果表明:常温下试样在受到剪切力后,在剪切区的裂纹周围产生了大量的孪晶;高温下试样的剪切区内产生了明显的绝热剪切带,并且在剪切带周围发现了大量平行的孪晶.在TEM下观察到剪切带内为等轴晶晶粒,在剪切区内发生了动态再结晶过程.     

不同温度下GS0202菌产酶差异的研究

利用电泳法及DEAE-Cellulose DE-52离子交换柱层析法对Arthrobacter chloropHenolicusGS0202菌分别在20和60℃下培养时产两种不同的酶进行研究。结果表明,20℃下培养所产的酶能水解人参皂苷Rb1生成人参皂苷F2,60℃下培养所产的酶能水解人参皂苷Rb1生成人参皂苷Rg3;找到了4条差异蛋白带,它们的分子质量分别约为66、47、35、22 ku;将60℃下培养得到的酶分离提纯,其纯酶的分子质量经电泳鉴定约为66 ku,与1号差异带的分子质量吻合。