土木工程外文翻譯--混凝土施工裂縫原因及防治-建筑結(jié)構(gòu)-wenkub
2023-05-19 14:04:26 本頁(yè)面
【正文】 ter the first layer top pouring concrete yet at the end of the beginning of the second period, and can turn from layered casting. This scheme is applicable to units within the time required, the supply of concrete less like the first option on that. This scheme is applicable to structure is too big and thickness of large area or length. Incline stratified: Requirements of slope not greater than cant 1/3, applicable to greatly exceed the length of the structure of the thickness of the three times. From the bottom layer of concrete casting, gradually move. measures Maintenance of mass concrete construction is a vital work. Maintain proper maintenance is mainly to control temperature and humidity, temperature, promote concrete outside the normal development of the strength of concrete and prevent the cracks of concrete and development. According to the specific circumstances of should as far as possible much maintenance period of time, after dismantling formwork should immediately, covering protection to prevent recent climate, sudden cold temperature, prevent and control in early concrete cracks and medium. The massive concrete curing, not only to satisfy the need that still should increase by artificial temperature control, due to temperature caused by deformation of the concrete cracking. After the pletion of the concrete curing time to keep the concrete surface spraying maintenance, such as reducing often humid heat outside pour cans, and prevent dry crack and promote the stable growth of concrete strength. In general 18h 12 ~ after pouring in immediately start maintenance, maintenance time not less than 28d or design age. 4 Cooled If in the hightemperature seasonal construction, should be in early general refrigeration adopted to reduce the water temperature, but the peak of concrete, water cannot too long, for a long time can cause excessive temperature range of temperature stress caused by large. In order to cut inside and outside, still should temperature in summer jiamoqiuchu undertake metaphase is cooled by water, river, general middle water lasted about two months. Later, water is made concrete cylindrical blocks the necessary measures to juncture grouting, generally USES water and cooling water through the bination scheme. Third, the conclusion Concrete crack, especially large volume concrete crack is currently scholars and engineering is an important problem of attention, through the above analysis, the material of mass concrete crack is mainly posed of temperature stress and concrete39。Construction cracks in concrete, causes and prevention Construction cracks of concrete reason for the external and internal. The initial mainly refers to the internal defects of concrete in early concrete, its internal hardening process will exist numerous micropores, airpocket and micro cracks, External refers to the load reason: temperature crack, dry shrinkage effect etc. In these, can produce various forms of concrete cracks. To grasp the construction process of raw materials, in pouring process configuration of progress and thickness, grasp timely maintenance work well, which can avoid concrete cracks. A, The cause of the tear initial defects of concrete Concrete is posed of cement, sand aggregate, mixed with water and other materials and formation of heterogeneity brittle materials. In the beginning, because hardened concrete construction and deformation, a series of problems, such as constraint in the concrete shape sclerosis will exist numerous micropores, airpocket and micro cracks of concrete that usually called initial defects. Micro cracks is usually a cracks in the concrete, bearing, and some other function not harm. But under load, temperature of concrete, shrinkage and function, micro cracks will be expanded and connectivity, and finally form the visible cracks of concrete, macroscopic crack, said it w
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