System Control Of Mass Concrete Construction For Not Carry Stress

Along with temperature and humidity to transform, concrete willing produce expand and contract, mass concrete is also such. But be the concrete to transform the stipulation (repress, bar) function, then want the companion to living to pull in response to the dint with pull to adapt to changes. When this kind of stress and strain over allowable of concrete, it willing produce crack and cause construction strength to lower and enduring ability to die. Construction of a mass concrete is in the construction process, because of cement let out in large quantity hydration heat and surface of a mass concrete let out heat, make its temperature, humidity cause to ascend and descend, and it causable constringency transform will be unavoidable. But this kind of constringency transform because of its inner part not even stress and all control functions exist with exterior, and make concrete produce to pull - stress and pull - strain. But because of concrete ability of anti-pull to stretch very weak, a mass concrete construction cause cracking will be unavoidable. Therefore, increase concrete anti - pull to stretch ability and reduce concrete control is very necessary.Base on above reason, for research of measure of anti-crack of mass concrete in not carry have very of important meaning.This paper use the principle of mass concrete temperature raise and down will make concrete inside stress and strain cause change, and mixture ratio of concrete effect temperature stress, and the principle of equilibrium management model of china-pole, and the test curve of temperature in engineering, and the model experiment "anti-pull" together of mass concrete etc, to studied mass concrete anti-crack theory in design, construction and management. Have to out:1 Temperature constructional reinforcing not can place in heat area to mass concrete design. Temperature constructional reinforcing of bottom of mass concrete need content that owing to temperature change produce bottom control stress smaller than anti-pull strength at the same. Get minimum rate of reinforcing to content construct request.2 By analysis and calculation about test result of stress, strain, and temperature of mass concrete model, and the test curve of a temperature for actual engineering, and bring up temperature of in concrete to ascend and descend function to use three theories and two pieces express. At the same time, in construction process for mass concrete, the theories of heat transfer by radiation for of center, bottom, surface of member also bring up the related calculation formula.3 The design theories of cooling pipe of play down internal temperature of mass concrete about diameter, length, arrange method, rate of flow, current velocity, reduce heat time, temperature disparity to in and out, reduce heating result etc.4 The theory of influence about concrete internal temperature and concrete crack because of transform of mixture ratio and pulverized fuel ash sophisticate quantity.5 Measure of preventing mass concrete absorb energy of sun.6 " Anti- put" together model theories about reduce the bottom control of mass concrete and control internal temperature stress of mass concrete.7 Make use of model theories of equilibrium management of chain-pole to control quality, planned speed, invest of mass concrete in construction process. Get theories about best management level.Consequently express, adoption above theories and result of test of mass concrete be in progress system control to construction, can effective reduce cracking in mass concrete not carry stress function. Therefore, this system theory is a good method about control mass resist stress cracking of not carry stress function.