浅谈涵闸的除险加固

介绍涵闸的裂缝渗漏，砼剥蚀和涵管周边渗漏等险情的处理方法。     

后张法预应力孔道真空辅助压浆技术

本文以厦门环岛路(海军码头~演武路段)A标工程为实例,对真空辅助压浆施工技术进行了研究和应用,并对其经济效益和应用前景进行了探讨。     

Flächige Abdichtung erdberührter Bauteile mittels Injektion

Die Schirminjektion ist ein Injektionsverfahren zur Abdichtung von erdberührten Bauwerken gegenüber Grundwasser, bei denen aufgrund der speziellen Gegebenheiten eine Behebung der Undichten des Baukörpers technisch nicht möglich oder ökonomisch nicht sinnvoll erscheint. Durch die Schirminjektion werden die Wasserwege im anstehenden Boden mit Kunstharzgelen verfüllt und abgedichtet, so dass der injizierte Boden die Funktion einer neuen Abdichtungsebene übernimmt. Der Beitrag beschreibt die Eigenschaften der verwendeten Gele und die qualitätsbestimmenden Schritte von der Voruntersuchung des Mauerwerks, über die Planung und Ausführung bis zur Qualitätssicherung und Dokumentation. Auch ökologische Aspekte der Injektion im Boden werden angesprochen. Waterproofing of Subgrade Constructions by Curtain Grouting. Curtain grouting is a method for waterproofing subgrade constructions where the sealing of the leakages in the construction is technically not possible or economically not sensible. By this kind of grouting the capillaries and cavities in the soil surrounding the construction are filled and sealed with polymeric gels. The grouted soil forms a new waterproofing body outside the structure. The properties of the used gels are described as well as the necessary steps to control the quality, including preliminary enquiries of the masonry, planning and execution of the grouting process, quality control and documentation. Also ecological aspects of grouting in soil are discussed.     

灌注桩桩端后压浆效果的室内模型试验

通过室内模型试验,对桩端后压浆灌注桩进行静载试验以及开挖观察,探讨了加固体的性状以及压浆参数对单桩承载力特性的影响,分析了灌注桩荷载传递特点和桩端阻、侧阻随荷载增加的变化趋势。经试验发现：压浆量、压浆压力以及岩土的可灌性是影响加固体性状的主要因素;浆液上返与桩周土作用形成的复合桩身形式对桩侧摩阻力影响较大,桩侧扩径效果明显处其侧摩阻力提高幅度大;桩端后压浆改变灌注桩承载力特性,常规桩表现出摩擦型端承桩性质,桩端压浆后表现出端承桩特性。     

裂隙岩体灌浆特性的研究

裂隙是灌浆的主要对象，应用幂律液体摩阻力定律，推导出灌浆压力，浆液特性，裂隙开度及浆液扩散半径之间的关系式。在此式基础上，分析研究了浆液趋于牛顿浆液时裂隙中的压力分布，以及灌浆各因素之间的相互影响关系     

粉煤灰对硫铝水泥基注浆材料强度及黏度的影响

研究了粉煤灰对硫铝水泥基注浆材料的强度及黏度的影响.试验表明:粉煤灰对硫铝水泥基注浆材料早期强度有削弱的作用,而对于其后期强度,在合适的掺量下,可以使得硫铝水泥基注浆材料强度提高;粉煤友在一定掺量下还能有效降低硫铝水泥基注浆材料的黏度.     

600kt/a甲醇装置压缩机组的无垫铁安装及无应力配管

介绍了600kt/a甲醇装置中压缩机组的特点,论述了大型压缩机组的无垫铁安装及其无应力配管,从安装精度、选择灌浆料、如何灌浆以及如何无应力配管的角度阐述了压缩机组在安装过程中的质量控制点。     

Investigations on the cementitious grouts containing supplementary cementitious materials

Concrete structures often exhibit distress during their service life due to one or more of the following causes: faulty design, use of substandard materials, poor construction, misuse or overloading. Of these, poor construction practices result in porous concrete which necessitates remedial and strengthening measures, if a structure is to meet the strength, serviceability and durability requirements, for which it has been originally designed. However, before strengthening the structure, the integrity of the concrete should be restored, which is often carried out through grouting using cement slurry, followed by grouting with epoxy or low viscous monomer. Grouting using cement slurry to fill up the voids in porous matrix of the concrete is the most simple and economical method, requiring less capital investment and skills. However, there are problems associated with cement grouting, such as shrinkage, stability of the grouts, etc. These problems associated with cement grouting can be solved by using cementitious grouts, i.e., grouts containing supplementary cementitious materials (SCMs) such as fly ash, ground granulated blast furnace slag (GGBS) and silica fume (SF) as admixtures in cement grout. This paper gives the results of the investigation undertaken to evaluate the flow, strength and durability characteristics of the cementitious grouts.     

Penetrability due to filtration tendency of cement-based grouts

Grouting is a widely used method for strengthening and sealing rock, soil and concrete. The possibilities for sealing structures are of great importance from both an economic and environmental point of view. The cost of grouting has in certain projects been as high as the cost of blasting and excavating the tunnel. To improve the technique for grouting with cement-based material, it is necessary to examine the properties of the grout mixture used. The ability of a grout to penetrate cavities, channels and porous material (penetrability) depends on two things: rheology and filtration tendency. Extensive laboratory tests on stable, low w/c-ratio grouts show that the most significant limitation to their penetrability is the tendency of cement grains to agglomerate into an impermeable filter cake. In this report, the ability of a grout to prevent passing obstructions in the flow path without the cement grains clogging and preventing further penetration is called the filtration tendency. An inert material mixture and a cement-based mixture are used in these investigations. The inert material does not react with the water added to the mixture. The cement grouts used are based upon three types of commercially available Portland cements and two Portland cements with modified grain-size distribution curves.Tests performed show that grain-size and grain-size distribution are of great importance to filtration tendency. According to experiments performed with inert and cement material, it seems to be advantageous for penetrability to have a grain-size distribution that does not contain too many fine or coarse grains. It is reasonable to believe that the grain-size distribution should be relatively steep (narrow grain-size range) between minimum and maximum grain-size. The maximum grain-size is of importance in terms of, for example, d₉₅. Too great maximum grain-size will prevent penetration of the mixture through obstruction of the flow path.According to the tests, the value of d₉₅ should be 4–10 times less than the aperture to be penetrated by the cement-based mixture. Small amount of small grain-sizes are also important in achieving low filtration tendency of the grout. This is because of the increased tendency for small grains to flocculate into larger agglomerates, compared to larger grain-sizes. The filtration experiments with cement-based grouts show that parameters such as surface chemistry (use of superplasticisers) and cement chemistry (hydration of cement grains) will strongly affect the filtration tendency of the mixture. To visualize the phenomenon of filtration tendency, it can be investigated to a larger-than-usual scale. Filtration experiments to a scale of approximately 100:1 have been performed in order to observe influences of grain concentration and penetrated slot aperture. It can be seen that the grain-sizes used (monodispersed and inert mixture) should be at least 2–3 times smaller than the aperture to be penetrated by the mixture.     

混凝土裂缝修复剂的研制与应用研究

为了克服水泥裂缝修复材料的不足,通过环氧树脂和氢化双酚A环氧树脂、活性稀释剂、固化剂及偶联剂等物质,研制出用于修复静止裂缝和活动裂缝的两种低粘度裂缝修复用灌浆材料。