龙滩水电站碾压混凝土坝高气温条件下施工技术

碾压混凝土是一种千硬性混凝土．一般采用通仓薄层连续施工，较常态混凝土更易受到高气温、强烈日晒、蒸发、相对湿度、刮风等因素的影响．故碾压混凝土一般避开高温季节施工。国内也有碾压混凝土在高气温条件下施工的先例．但大都工程量不大，坝不高，而龙滩大坝工程规模巨大，工期紧．必须进行全年施工方能实现进度目标。所以必须采取切实有效的综合温控措施，保证在高气温条件下和高辐射热件下碾压混凝土连续、快速施工．以降低碾压混凝土的最高温度和防止裂缝的产生。

Construction Technology for RCC Dam under High Temperature at Longtan Hydropower Station

Roller Compacted Concrete(RCC) is a hard concrete and generally is placed successively in thin layers at full section. Comparing with conventional concrete , RCC is more easily effected by high temperature, strong sunshine, evaporation, relative humidity and wind blowing . Therefore, RCC placement is normally avoided in hot seasons. In China , RCC placement was carried out in hot seasons but at some projects with low dam height and small volume , while at Longtan dam with huge placing volume and short construction period , the construction schedule can only be fulfilled by continuous construction . Therefore, some effective temperature control measures must be taken to ensure continuous and rapid construction of RCC under high temperature and high radiant heat and to decrease maximum temperature of RCC and prevent RCC from cracking.