黄河中下游水闸混凝土强度变化规律研究

Study on Change Law About Sluice Concrete Strength in the Middle and Lower Reaches of the Yellow River

黄河中下游水闸因所处环境条件相似,故各种不同配合比及强度等级的混凝土强度理论上具有相似规律,针对已开展的43座水闸混凝土强度现场安全检测成果,分环境、分构件类型进行了统计分析,得到不同构件混凝土强度的推荐检测方法。考虑龄期、环境因素,研究了构件混凝土强度变化规律。结论如下:水闸现场安全检测中,闸底板和涵洞底板混凝土检测方法推荐钻芯法,闸墩及涵洞侧墙混凝土检测方法推荐钻芯修正回弹法,闸顶板、胸墙、闸门、涵洞顶板检测方法推荐回弹法,机架桥混凝土检测方法推荐超声回弹综合法;13~45 a龄期内,混凝土强度呈现增长趋势,第Ⅱ类构件增长率最大,第Ⅰ类构件次之,第Ⅲ类构件最小,从设计强度角度看,C13混凝土强度的增长率大于C18混凝土的;龄期大于45 a后,混凝土强度趋于定值。

Because the sluices that located in the middle and lower Yellow River have a similar environment condition,a variety of different strength grades and different mixture ratios of sluice concrete strength has a similar rule in theory.In order to explain the relationship of con-crete strength and environmental conditions and their inherent law after using for many years,this paper made a statistical analysis on the different environment of different types of concrete strength results which was showed by the site safety inspection of forty three sluices.Finally found the recommended concrete strength testing method for different concrete types.According to age and environmental factors,this paper studied the strength of concrete and got the following conclusions.In sluice site safety inspection,sluice floor and culvert bottom concrete testing methods are recommended as core method,pier and culvert sidewall concrete testing methods are recommended as core fixed rebound method,roof,parapets,gate and culvert roof testing methods are recommended as rebound method and machine bridge concrete testing method are recommended as ultrasonic rebound synthetic method.In the age of13-45a,concrete strength shows a trend of growth,the type II's trend is the highest,the type I is the second and the type III is the minimum.Viewing from the design strength perspective,the No.150concrete's growth rate is faster than that of the No.200concrete.Concrete strength tends to be constant value when their age is longer than45a.