西江特大桥大直径桩基混凝土配合比设计验证与应用

On Design Verification & Application of Large-diameter Pile Concrete Mixture Ratio of Xijiang Super-large Bridge

江门至肇庆高速公路横跨喀斯特地区,桩基施工技术复杂,对桩基混凝土质量要求高。以西江特大桥大直径桩基混凝土配合比设计为研究背景,对承包人申报的大直径桩基配合比标准试验进行了平行验证。其混凝土强度、耐久性、和易性等性能指标与申报的试验指标有差异,分析了承包人试验室试验指标出现这些差异的原因。该混凝土配合比在施工应用后,符合工程施工要求,桩基完整性检测结果均为Ⅰ类桩。

The expressway section from Jiangmen to Zhaoqing crossing Karst area,its pile foundation construction technology is complicated with high requirements to pile foundation concrete quality.With the background of Xijiang Super-large Bridge on its large-diameter pile foundation concrete mix proportion design,the standard test by the contractor on large-diameter pile foundation mix proportion is parallel validated,and some performance indicators such as concrete strength,durability and workability have index differences from the declaratory test data.Therefore,the causes to appearing differences of the contractor lab test indicators are analyzed.The concrete mix proportion can meet the requirements of engineering construction after the practical application,and moreover,the testing results of pile foundation completeness all can arrive at Type-Ⅰ Pile.