Effect Of Construction Load On The Axial Deformation Of High-rise Buildings

So far, there have formed a mature theoretical system about the creep a ndshrinkage of concrete. But there are some problems in suspense. Based onlimitations of original material models and calculation method resulting fromdevelopment of high performance concrete materials and structure system,experiment on shrinkage of high-strength and self-compacting concrete was done,and effect of cross-section shape on shrinkage and creep of concrete wasdiscussed combined with B3model, then the applicability of the assumption thatthe early age concrete creep and the stress is linea rly dependent and conform tothe Boltzmann superposition principle was studied experimentally, verticaldeformation of high-rise buildings considering the construction process andconcrete time-dependent characteristics was analysed at the same time in thispaper. Three sections was included specifically as follows:First of all, the experiment of shrinkage of high-strength, self-compactingconcrete was carried out. The applicability of the existing prediction modelsdomestic and overseas to high-strength and self-compacting concrete wasanalysed. And the experimental datas and the prediction datas werecomparatively analysed. The experiment results show a best agreement with theBa ant-Baweja B3model and the GL2000model, and shrinkage ofself-compacting concrete is significantly larger than that of ordinary concrete atthe early age.Secondly, construction process was simulated through loading step by step.Experimental study on the effect of different load history on creep of concretewas done. The question whether the early age concrete creep and the stress islinearly dependent and conform to Boltzmann superstition principle wasdiscussed. And experimental research on the effect of cross-section shape ontime-dependent defotmation in concrete was carried out, comparative analysisbetween the simulation results and test results was done. As can be seen from theresults, reasonable consideration of the applicability of the linear assumptionsand superposition principle together with effect of cross-section shape ontime-dependent defotmation in concrete is needed when carrying on construction process analytical research of high-rise buildings by numerical simulation.Lastly, a30layers frame-core tube structure was established using MIDASsoftware. Combined with the test results of the second chapter, we can concludethat the Ba ant-Baweja B3model and GL2000model is in more accordance withthe actual situation when making predictions for the vertical deformation ofhigh-rise building structures. The cross-section shape coefficient influence moreon the shrinkage of concrete than on creep. And with the development of the ages,influence decrease gradually. It has no significant difference for the influence ofcross-section shape on shrinkage and creep of concrete with different strength.The effect of different construction speed on the axial deformation of theconcrete structure is quite obvious.