机拌变态混凝土在大藤峡纵向围堰中的应用

Application of Mechnical Mixing Abnormal Concrete in Longitudinal Cofferdam of Datengxia Hydro Project

为解决狭长仓面变态混凝土施工存在的问题,通过分析变态混凝土浆液配合比、仓内注浆工艺,根据大藤峡纵向围堰的特点并结合国内变态混凝土施工经验,提出对纵向围堰上、下游段变态混凝土采用在拌合楼集中拌制、自卸汽车运输、小型挖掘机配合入仓、振捣车振捣密实的方式施工,减少了施工干扰,解决了人工注浆量随意性较大和混凝土均质性较差的问题。通过外观和取芯检查发现:混凝土表面光滑、无蜂窝麻面;内部密实,层间结合好;抗压强度和防渗等级满足设计要求。该施工工艺可为类似狭长仓面碾压混凝土施工提供参考。

In order to solve the problems existing in the construction of abnormal concrete on the long-narrow warehouse surface,through the analysis of the mix proportion of the abnormal concrete slurry and the grouting technology in the warehouse,according to the characteristics of the longitudinal cofferdam of Datengxia Hydro Project and combined with the construction experience of the abnormal concrete in China,it is proposed that the abnormal concrete in the upstream and downstream sections of the longitudinal cofferdam should be mixed in the mixing plant,transported by dump truck,put into the warehouse with the cooperation of small excavators,and vibrated and compacted by the vibrating truck,which reduces the construction interference and solves the problems of large randomness of artificial grouting and poor concrete homogeneity.Through the appearance and coring inspection,it is found that the concrete surface is smooth,without honeycomb and pitted surface;the internal is dense,and the interlayer bonding is good;the compressive strength and anti-seepage grade meet the design requirements.The construction technology can provide a reference for the construction of similar long-narrow warehouse surface roller compacted concrete.