Research On Temperature Stress And Crack Reductions Of Large Thickness Steel Plate Concrete Composite Shear Wall

With the rapid development of society,shortage of land resources,more and more super high-rise building is built,high-rise buildings appear constantly in the domestic and foreign.Due to the large bearing capacity good ductility and convenient construction etc of steel concrete composite shear wall,many high-rise designers favour it.because lager requirement of carrying capacity,the shear wall thickness are above 0.8m,which belongs to the category of large volume concrete.It leads to Super High-Rise Steel-Concrete Composite Shear Wall with concrete hydration heat and larger internal heat which is difficult to timely release,Under internal and external constraints of the wall,it is easy to produce large temperature stress and temperature crack.At present,the research on steel concrete composite shear walls is mainly focused on its seismic performance,there are few studies on its temperature crack mechanism and temperature crack control.This paper attempts to control temperature cracks in two aspects,first study the concrete mix ratio optimization of steel reinforced concrete shear wall and the relationship between the factors of concrete,selected low hydration heat and strength and fluidity are optimum proportioning of concrete.The first high-rise of northwest"Guorui Xi'an financial center" as the background,selected two shear wall to monitor and analyze temperature cracks,concrete strain,development of the wall which is first case of sprcw full-scale model test in the country,summed up the relationship between temperature variation between capacity and crack.The difference of temperature distribution,early crack and compare the two wall draw shear wall with different thickness on the development characteristics is study.According to the "constraint" and "temperature constraint" of crack force theory,Calculating the cracking index of each age,the most dangerous period of the wall cracking and parts,meanwhile puts forward the corresponding prevention and control measures and key.Because of the interior wall cracks is not easy to observe,in order to verify the accuracy of the theoretical analysis,calculation and analysis of changes of wall cracking index within 28 days after the completion of concrete pouring by using finite element simulation software,the simulation results intuitively reflects the law of development and the wall cracking index calculation and the theory of mutual authentication.The results of this study revealed that the temperature variation of large thickness steel concrete composite shear wall,systematically explains the development mechanism of temperature crack,put forward the choice of concrete material,curing time and methods of crack control,which can provide a theoretical and experimental basis for the research and application of mixed concrete steel composite shear the wall.