【正文】 stress of drawing in the structure in plain concrete must rely on the concrete oneself to bear. Require avoiding the stress of drawing or only very small stress of drawing appears of the general design. But the concrete is cooled from maximum temperature to the steady temperature of operating period in constructing, often cause sizable to draw the stress within the concrete. The temperature stress can exceed other outsides and load the stresses caused sometimes, know change law, temperature of stress for carry on reasonable structural design and construct extremely important.Analysis of 2 temperature stressesIt can be divided into following three stages according to the forming process of the temperature stress: (1)It is early: It needs generally 30 day from beginning building concrete to finishing sending out heat basically by cement. There are two characteristics at this stage, first, the cement emits a large amount of heat of hydration, second, mix and congeal the changing sharply of elastic model quantity. Because of the change of elastic model quantity, form the remaining stress in the concrete in this period. (2)Middle period: Up till the concrete is cooled until stability temperature from cement send out heat function basically when expiring, in this period, the temperature stress is mainly because the cooling of the concrete and external temperature change cause, these stresses and remnants stresses that is formed in early days are superposed, mix and congeal the elastic mould amount that goes to and does not change much during this period. (3)Later period: Operation period after the plete cooling of concrete. Temperature stress whether external temperature change causes mainly, these stresses and first two kinds of remnants stresses are changed and added. It can be divided into two kinds according to the reason why the temperature stress causes: (1)Spontaneous stress: There are not any restraints or totally static structure at the border, if inside temperature is nonlinear distribution, temperature stress appearing because structure restrains from each other. For example, the body of mound of the bridge, the physical dimension is relatively large, surface temperature is low when the concrete is cooled, inside temperature is high, present the stress of drawing on the surface, present the stress of pressing in the middle. (2)Restrain the stress: All of the structure ones or it restrain external one some border, can39。t deformation doing, often cause the crack too. The concrete is a kind of fragility material, tensile strength is about 1/10 of the pression strength, is it carry on one39。外文翻譯一、原文Discuss the construction temperature andcrack of the concrete lightlyThe summary: In order to prevent the owners of the concrete work of claims, we must do a good job in the construction process in the temperature and crack control, through observation live for many years, through consulting the monograph about stress within the concrete, explain to concrete temperature reason, onthespot concrete control and measure, prevention of crack of temperature that crack produce. Keyword　　Concrete　　Temperature stress　　Crack　　Control1. The concrete occupies the important position in modern engineering construction. But today, the crack of the concrete is paratively general, the cracks are nearly omnipresent in the science of bridge building. Though we take various kinds of measures in constructing, careful, but the crack still occurs now and then. Tracing it to its cause, it is one of them inpletely that our change to concrete temperature stress pays attention to. In the large volume concrete, temperature stress and temperature control are significant. This is mainly because of the reason of two respects. First of all, concrete often appear the temperature crack in not constructing, influence the globality and durability of the structure. Secondly, in the course of operating, the temperature change has remarkable influence that can39。t be ignored on the stress state of the structure. We meet to construct temperature crack in mainly, so only to origin cause of formation and treatment measure, concrete of crack make a discussion in constructing this text. Reason of a crack It has many kinds of reasons to produce the crack in the concrete, it is mainly the changes of temperature and humidity, fragility and disparity of the concrete, and the structure is unreasonable, the raw materials is not up to standard (if the alkali aggregate react), the template is out of shape, the foundation does not subside etc. evenly. The cement emits a large amount of heat of hydration when the concrete is hardened, inside temperature is rising constantly, cause the stress of drawing on the surface. In the course of lowering the temperature, is it congeal foundation pay restrain to mix always later stage, will present the stress of drawing within the concrete. Reducing of temperature can surface cause heavy stress of drawing very in concrete too. When these draw the stress and go beyond resisting the ability of splitting of concrete, namely will present the crack. A lot of inside humidity of concrete change very light or change relatively slow, surface humidity might change heavy the violent change takes placing. Such as maintaining thoroughly, when getting wetter when not doing, contract surface there aren39。s shoulder or back limit when draw out of shape to have（～）104 only, is it carry on one39。t out of shape and stress not cause not free. Such as case beam roof concrete and guardrail concrete. These two kinds of temperature stresses draw back stresses caused to act on with the doing of concrete together frequently. It is a more plicated job to want to analyse the distribution, size of the temperature stress accurately according to known temperature. In case of great majority, need to rely on the model test or the number value to calculate. To is it make temperature stress have siz