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Study On Temperature Field And Thermal Stresses Of Hydro-structure Considering The Function Of Steel Bar In Construction Period

Posted on:2007-05-11Degree:MasterType:Thesis
Country:ChinaCandidate:C H ChenFull Text:PDF
GTID:2132360182488560Subject:Structural engineering
Abstract/Summary:PDF Full Text Request
In order to grasp distributing regularity of temperature fields and thermal stress of mass reinforced concrete structure, and understand cracking mechanisms of temperature crack, it's necessary to analyze temperature fields and thermal stress of structure in FEM. But typically plain concrete material is only considered when it is calculated in practical engineering analysis. Although the method can simplify calculation model and reduce the volume of calculations, there is deviation between result of calculation and practice without considering the effect of steel bar.FEM is expounded in detail about temperature field and thermal stress of mass concrete in the paper;The basic principles and process of simulative analysis in software ANSYS are introduced specific at length. Based on regulating major engineering inQinhuai River-construction of pier in Sancha River, the temperature fields and thermalstress about the pier of reinforced concrete are analyzed in the period of construction by ANSYS. There are some factors mainly considered such as heat of hydration of cement, heated measure, change of air temperature, pipe cooling , batch construction an so on.. In the process of calculation, simulation about Young's modulus of concrete of variety with time is realized using the function of UPFs. The construction scheme is optimized by comparison between six calculation results, which provides theoretical basis for the owner making appropriate decision.Suitable steel bar which is configured in the interior of pier in Sancha River, can prevent the concrete from cracking. Addition of steel bar can increase conductivity for heat, and reduce specific heat of concrete. Aiming at the change of the two thermal properties for concrete, the effect of steel bar on temperature fields and thermal stress is analyzed in action of hydration heat by FEM in ANSYS, which proves the positive effect of configuring steel bar in reducing early temperature stress.Addition of steel bar can change thermal properties of concrete, at the same time, it can effect on mechanics characteristic. After configuration of steel bar, concrete mechanics characteristic is consolidated. Mechanism of anti-crack and limit-crack about temperature reinforcement are analyzed further in the paper. The principle of configuring steel bar about the control-crack of mass concrete is summarized.Summary of above analysis, anti-crack function of steel bar in early concrete structure is obvious, so it's necessary to consider beneficial effect of constructional steel bar in research of temperature control in mass reinforced concrete. Effective reference is provided in the paper for accurately analyzing the problem of crack prevention under construction of mass reinforced concrete.
Keywords/Search Tags:Mass reinforced concrete, FEM simulative analysis, Pipe cooling, Temperature field, Thermal stress, Constructional steel bar, Anti-crack function
PDF Full Text Request
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