Research On Crack Control Of High-rise Building Super-length Mass Concrete Foundation Slabs

With the widespread application of mass concrete structure in current engineering construction, the structure performance and construction technology become a focus of attention in engineering. In the prophase of mass concrete pouring and solidification heat of hydration formed complicated temperature field. The temperature field forms the temperature stress the cause concrete dehiscence without loading. The menace for structure load-carrying properties and secure service life can't be ignored.This thesis begin with mass concrete temperature field of hydration and correlative reason of algorithm, select project"The New Technology World of SIP Science & Technology Park"as its background, adopt FEA software ANSYS, imitate temperature field and stress field of mass concrete foundation slab in the duration of one month since concrete was cast, supply phasic achievement of trend appraisal of temperature-caused-dehiscence and implement of scientific cooling technology. Secondly, according to the FEA computed result, an advanced scheme to real-time monitoring of temperature field was also advised. Large numbers of temperature sensors were embedded, from which the thermo sensors read data. The fact disciplinarian of temperature field was analyzed and contrasted with FEA computed result. Differential resistance strain gauges were also embedded to monitor early-age mass concrete strain. The disciplinarian of it was studied. At last, Methods to control temperature crack of mass concrete from several aspects such as design measures, concrete material, construction schedules .etc are summed up.On the basis of the researches mentioned above, some crucial conclusions are acquired as follows:(1) The FEA simulation technology adopted to compute temperature field and stress field in this paper is effective for evaluating temperature-caused-dehiscence and designing temperature crack-controlling measure. (2) Method of embedding temperature sensors in concrete beforehand in monitoring and adopting circuit-detection apparatus can greatly increase the precision of measurement and high speed, this method is worthy of being popularized. (3) In practice, shrinkage-compensating concrete have effect on compensating shrinkage which caused by dry and cold in medium-term. (4) Differential resistance strain gauges were embedded to monitor mass concrete strain and autogenous volume deformation .etc. The effect of crack control can be evaluated from the monitored result. (5) All relevant factors are demanded for full consideration, and then careful temperature crack controlling scheme should be established with the method of sys tem engineering.