外文翻译--论建筑工程中混凝土裂缝的预防与处理

外文翻译--论建筑工程中混凝土裂缝的预防与处理内容摘要：

rrow summer. The emergence of such cracks will cause reinforcement corrosion and internal concrete carbonation, and seriously affect its function and durability. The main preventive measures: First, try to use low heat or cooked cement, slag cement, fly ash cement. Second, under the premise of ensuring the strength of concrete. Improve the aggregate gradation, fly ash or superplasticizer to reduce the amount of cement. Third, to ensure the workability of concrete and meet the construction needs of the premise, lower watercement ratio. Is to improve the production process of concrete, reduce the temperature of concrete pouring. Is mixed with a certain amount of concrete retarders, delayed the emergence of the thermal peak time. Is to strengthen the concrete temperature monitoring, and to take timely cooling or insulation measures, reducing the temperature difference between inside and outside of the concrete. 7 is to strengthen the concrete curing, pouring concrete, timely cover with wet straw mat, linen piece, and note the sprinkler maintenance, appropriate to extend the curing time. Eight is to configure a small amount of the small size reinforced concrete or mixed fiber material to control the temperature cracks of the concrete within a certain range. Chemical reaction caused by cracks and Prevention Alkali aggregate reaction cracks and steel corrosion cracks in two kinds of cracks caused by the chemical reaction is generally divided into the reinforced concrete structure. Construction works is limited to the position of the concrete, after mixing some alkaline ions, these ions react chemically with some of the reactive aggregate expansion and to absorb the moisture in the surrounding environment, resulting in shortening of concrete, Splitting. Such cracks generally appear in the concrete structure during the event difficult to remedy, and should therefore take effective measures to prevent construction. The main preventive measures are: First, the choice of the alkali reactivity of small gravel aggregate. Second, the selection of lowalkali cement and alkalifree admixture. The third is optional and can inhibit the admixture of alkali aggregate reaction. Adverse phenomenon due to the reinforced protection of reinforced concrete structures during construction caused by bad thin, exposed tendons, cellular, pockmarked face, making the hazardous substances and exposed reinforcement through the concrete and internal reinforcement to react to rust, corrosion of reinforced volume expansion, resulting in concrete spalling, cracks of this type generally along the reinforced positions. The usual precautionary measures。 First, before pouring concrete, strict inspection of reinforced protective layer to ensure that its thickness to meet design requirements, while ensuring a solid steel banding, and accurate position, to avoid the reinforced vibrated concrete shift and exposed tendons. Second, using the class with a good gravel aggregate concrete prepared. Vibration pacting concrete pouring. Timely processing of the concrete after form removal slag, cellular, and Ma surface phenomenon. 4 Common cracks approach Surface repair method Surface repair method is a simple, mon repair method is mainly applied to the processing of stability and no effect on the structure carrying capacity of surface cracks and deep into the cracks. The usual treatment measures in the cracks in the surface of smear grout, epoxy mortar or concrete surface brushing paint, asphalt and other anticorrosion materials, continue to crack in order to prevent the concrete role in protection while using crack surface paste of glass fiber cloth, when the concrete surface cracks in larger quantities, the distribution of the surface of a wider, often used to add a layer of cement mortar or fine aggregate concrete method of the overall surface treatment, while the overall surface should configure twoway steel mesh. Concrete replacement method Concrete replacement method is an effective way to deal with serious damage to the concrete, this method is removed clean, the first damage to the concrete, wetting, and then brushing the binding layer, and finally replacement into the new highlevel grade concrete or other materials. Replacement material: ordinary concrete, cement mortar, polymer or modified polymer concrete or mortar. Structural reinforcement When the cracks affect the performance of concrete structures, it is necessary to consider taking a reinforced concrete structure processing. Structural reinforcement monly used mainly in the following ways: outsourcing steel ponents, paste, steel reinforcement。 additional support points on the ponent reinforcement。 prestressed reinforcement in the ponent. Grouting, caulking block method Grouting method applies to the structural integrity of the influential or the repair of concrete cracks in the impermeable requirements, it is the use of pressure equipment will cementing material pressure concrete cracks cementing material hardened with concrete to form a whole, and thus play blocking the purpose of reinforcement. Commonly used in the cementing material grout, epoxy, methacr。