(40+168+40)m系杆拱连续梁桥拱内压注混凝土施工技术

Research on Construction Technology of Concrete Filling in (40+168+40)m-Series Arch Continuous Beam Bridge

以客运专线东海特大桥(40+168+40)m系杆拱连续梁为背景,针对客运专线特大拱肋压注混凝土施工技术展开研究。研究表明:拱肋内混凝土泵送顶升法采用抽真空灌注工艺;泵送自密实补偿收缩混凝土,混凝土含气量应小于2.5%,初凝时间应大于完成浇筑一根钢管所用的时间,弦管内混凝土采用一级或二级泵送,缀板内混凝土采用三级泵送;入泵时坍落度范围宜为20-26cm,扩展度宜控制为50~65cm。

Based on the continuous beam of the Donghai Special Bridge(40+168+40)m-seam arches on the passenger dedicated line,this paper studies the construction technology of the large-arch ribbed concrete for passenger dedicated lines. The research shows that the concrete in the arch rib is filled by vacuum pumping process from the low point to the high point;the pumping self-compacting shrinkage concrete,the concrete gas content should be less than 2.5%,the initial setting time should be greater than the time required to complete the pouring of a steel pipe. The concrete in the string pipe is pumped by the first or second stage. The concrete in the slab is pumped by the third stage. The slump range should be 20~26 cm when the pump is inserted. The expansion should be controlled to 50~65 cm.