抑制碱活性与混凝土配合比优化相结合的思路分析  

Analysis on the Idea of Combining Inhibition of Alkali Activity and Optimization of Concrete Mix Design

作　　者：王雷 娄鑫[1] WANG Lei;LOU Xin(Sinohydro Bureau 7 Co., LTD, Chengdu, Sichuan, 611730)

机构地区：[1]中国水利水电第七工程局有限公司,四川成都610213

出　　处：《四川水力发电》2021年第6期20-23,共4页Sichuan Hydropower

摘　　要：固增水电站EPC工程项目骨料场位于距固增乡3 km附近的莫冲村,骨料场的砂岩全部存在碱活性问题,若不加以处理,在未来的5~20 a内,已施工的混凝土极可能出现不同程度的膨胀裂缝而产生巨大的安全隐患。为解决这一问题,通常采用高掺粉煤灰的传统技术,但高掺粉煤灰会导致混凝土早期强度低或成本增加较多,因此,解决骨料碱活性问题成为该工程成败的关键。阐述了将混凝土中的粉煤灰掺量提高到30%,变更混凝土龄期从28 d到90 d,不但解决了混凝土的碱骨料反应膨胀问题、提高了混凝土的早期强度,还降低了混凝土的水化热和配料成本。Aggregate yard of Guzeng Hydropower Project is located at Mochong village which is 3 km away from Guzeng Township.Sandstone in the aggregate yard is with alkali activity,if not being treated,in the coming 5-20 years,the concrete will probably have expansion cracks of varying degrees,which will cause huge safety hazards.The traditional way of solving this problem is to increase the content of fly ash,however,high fly ash content will lead to low early strength or increase the cost of concrete.Therefore,solving the problem of aggregate alkali activity without increasing the cost of concrete is the key to the success of the project.This paper describes the engineering practice of solving the problem of alkali aggregate reaction,improving the early strength of concrete,meanwhile reducing the hydration heat and batching cost of concrete through increasing the content of fly ash to 30%and changing the age of concrete from 28 days to 90 days.

关 键 词：骨料碱活性 潜在碱活性 90 d龄期强度 高掺粉煤灰 固增水电站 

分 类 号：TV7[水利工程—水利水电工程] TV41