Study On Theory And Its Application To Temperature Control And Crack Prevention Of Concrete Of Hydraulic Structures

The crack prevention of hydraulic structures concrete is thoroughly studied from theory and practice in this paper. A lot of practical problems are solved. The main contents are as follows:a. The 3-D simulative calculation program concerning temperature field and creep stress field applying pipe cooling is conducted by adopting more advanced simulation technique. Thereby an effective method is suggested for computing the temperature field and stress field of mass concrete. That method can simulate precisely for RCC(Roller compacted concrete) dam which constructed layered.b. Some precise formulae are deduced for analysis 3-D temperature field of concrete that set many pipes. The basic Sub-structural computation theory of the temperature field of pipe cooling is suggested, some examples and practical projects are given to testify this method be reliable and effective.c. By applying this method, temperature control and crack prevention of concrete of E-he sluice is studied. There are better crack prevention effects for guiding construction timely by forecasting temperature and stress of concrete.d. By applying "None homogeneous multi-laminate element", Hong-kou RCC gravity dam's simulation computing of temperature field and stress field at construction period and operation period for all courses and many factors.e. Some kinds of methods are discussed in detail for temperature field back analysis, and artificial neural network method for back analysis of thermal parameters of concrete is suggested.f. The stress status of concrete at face of sluice pier in the case of cold wave, pipe cooling and cast-in-place partial sluice pier and so on. And then cracking mechanism of concrete of hydraulic structures such as piers is studied thoroughly, measures of crack prevention in such structures are suggested.g. Temperature control and crack prevention of concrete-the simulation analysischaracteristics of dams construction with MgO concrete, the theory apply "equivalent time" to the model for computing autogenous volumetric change of concrete which be relate to temperature history. It makes computing autogenous volumetric change of concrete be realized at case of arbitrary temperature history, so the problem puzzled engineer over a long period of time may be dispelled.