衬砌工程中混凝土板短时间内发生破坏的原因分析

Cause analysis of short-time failures of concrete slabs in lining projects

为系统地研究鸡龙河渠道衬砌过程中混凝土板经过一个冬季就发生快速破坏的原因,对混凝土板原材料质量、施工工艺、周围影响因素等逐一排查,利用Raman光谱和成分研究方法,分析出混凝土板侵蚀物为硅灰石膏,由此确定水泥基材料与高含量SO_(4)^(2-)的土壤和水密切接触,同时在低温、潮湿的共同催化下,发生化学反应,使混凝土中的C-S-H凝胶在上述因素综合作用下变成灰白色无胶结能力的硅灰石膏,导致混凝土板强度降低甚至完全丧失,造成混凝土板被侵蚀。

The raw material quality,construction technology,surrounding influencing factors,etc.of concrete slabs are investigated one by one in order to systematically study the cause of the rapid failure of concrete slabs in the lining process of Jilong River Channel after one winter.Raman spectrum and composition research methods are used for analyzing the result that the corroding material of concrete slabs is silica silica gypsum.It is determined accordingly that the cement base material is closely contacted with high content SO_(4)^(2-) soil and water.Meanwhile,chemical reaction makes the C-S-H gel in the concrete into gray thaumasite without cementing ability under the integrated action of the above factors according to the joint catalysis of low temperature and moisture,thereby resulting in the strength decrease and even complete loss of concrete slabs,and causing concrete slab erosion.