Temperature Limit Research Of Mass Concrete Between Internal And External

With China’s national economy developing quickly, structure of mass concrete incivil and industrial building emerges in a great quantity and has been widelyused.However, limitation of temperature between internal and external research ofmass concrete is rare and only stays at the level of semi empirical experience andtheory.Currently,the temperature is limited as no more than25℃. Therefore peopleadopts many unnecessary preventive measures in the engineering practice, in order tonot produce temperature crack on account of over the limits, that wastes a lot of themanual labour, material.But the results of quality control is not good. In view of theabove situation, some research work is did and stated below:1On basis of accessing a large number of literatures, paper introduces concretetemperature field using induction heat transfer theory, and gets temperature stress basiccalculation method with shrinkage and creep of mass concrete.2According to the composite material mechanics and the basic principle offracture mechanics, paper studies early elastic modulus and fracture energy parametersof concrete from micro to macro level and studies the quantitative relationship betweenfracture breaking stress and the parameters.3With detection the temperature changes of a building foundation board in thecity of Erdos, paper calculates the possibility of maximum temperature stress, whichcompares with fracture breaking stress. With above all, paper gets the securitytemperature limits of the building foundation board and compares with25℃, which isruled in standard. Practice proves that the project is safe and credible with the temperature limits between internal and external.The results of the study show that: the temperature limits between internal andexternal of mass concrete is not and should not be a constant, but a various mechanicalparameters relating to mechanical properties of early age concrete.1The temperature limits between internal and external of mass concrete fluctuatesin25℃, but not a constant, which relates to factors such as its size, structure form,foundation constraints, creep of concrete material, and the resistance. Theory researchshows that in normal temperature conditions, mass concrete is susceptible to earlycracks in3~10days, later cracking impossible.2According to the kelvin model, paper fits out early water slurry of elasticmodulus quantitative equation on the basis of the late the slurry hardening modulus,which is applied to the early age concrete elastic modulus calculation. The results showthat the effect is good.3According to the composite material mechanics, the basic principle of fracturemechanics and kelvin model. In a double tensile condition and hardening time, papergets a quantitative equation of concrete in theory. According to the experimental resultsof the literature, the calculation results show that the expression can better reflect theearly age concrete mechanics performance.4The temperature limits of mass concrete reaches25℃in instantaneous or above,that is not necessarily a cause of early cracks in the concrete due to the creep effect;Creep mainly is relevant to the volume proportion of the slurry viscous body.