Construction Technology Of Super Large-Span Prestressed Concrete Beams And Its Application

This article takes Chi Feng international convention center multi-purpose hall ceilings which used post-tensioning prestressed concrete beam structure system as example, to summarize the super large-span prestressed concrete beams construction technology.First, this article has optimized the high template support system's shaping, used the commonly used buckle type steel pipe scaffold support system, made the exhaustive design checking calculation, and used the reasonable structure measure, considered from time, security and cost three aspects , proposed when designing big template support system shaping, it should unify the concretes beams actual shape as well as the construction enterprise own technical force, use the versatility strongly, safe reliable, the relatively low economic cost buckle.Second, in the post-tension prestressed construction, it has taken the corresponding countermeasure after the selective analysis of prestressed loss reason. From the anchorage's shaping to the pull craft, proposed super large-span prestressed concrete tensioning the craft must pull from both sides symmetrically, the tension force examined with the elongation value should be controlled in the range of 0～±5 % ,to prevent pull crack in the structure.Third, to the temperature shrinkage fracture easy producing in mass concrete beams, we started with the reason of the crack to find the crack controlling measure. From the mixture ratio optimization, the selection of raw material to the reasonable control lamination casting thickness; From reducing the temperature of concrete before entering templet to strengthening maintenance, obtains that only the reasonable construction organization ,the correct plan of construction and the effective controls temperature plan are the key of mass concrete quality.Finally, conducts the research to the prestressed concrete beam's steel bar skeleton installment, proposed to breast working reinforcement protector, steel bar skeleton temporary support, attachment and other specific measures, has solved the installment beam steel bar skeleton common difficult problem.This article has studied the construction techniques of super large-span prestressed concrete beams five aspects. Through the example application, it has made the good comprehensive economy progress, has the strong instruction, also has certain promotion application value to the similar project construction.