一种新的抗推移质冲磨试验方法——高速水下钢球法的建立  

Development of a new test method for abrasion resistance of hydraulic concrete——high-speed underwater method

作　　者：丁建彤[1] 戴玭[2] 白银[1] 杨建国[1] 石研然[1] 

机构地区：[1]南京水利科学研究院水文水资源与水利工程科学国家重点实验室,江苏南京210024 [2]河海大学力学与材料学院,江苏南京210098

出　　处：《混凝土》2011年第12期5-8,共4页Concrete

基　　金："十一五"国家科技支撑计划(2008BAB29B04)

摘　　要：为了客观考察高强抗冲磨混凝土在泄水建筑物高速水流作用下的抗推移质冲磨情况,对DL/T 5150《水工混凝土试验规程》中的水下钢球抗冲磨试验方法进行改进,建立了高速水下钢球抗冲磨试验新方法。考察了水流速度、冲磨时间、钢球投影面积与试件表面积之比、钢球最大粒径等因素对新方法冲磨效率的影响,并采用有约束配合比均匀设计的方法优化钢球级配。确定新方法的试验参数为:叶轮转速4 000 r/min,近底水流速度3.8 m/s,钢球投影面积占试件表面积的50%,钢球最大粒径30 mm,钢球级配为8个准30 mm、17个准25.4 mm、33个准19.1 mm6、2个准12.5 mm,冲磨时间48 h。用强度等级为C9050和C9060的泵送和常态高强抗冲磨混凝土,对比了标准方法和新方法的冲磨效率。试验结果表明:与标准方法相比,新方法的冲磨效率提高了约3~4倍,冲磨时间缩短1/3,平均磨损深度从1~2 mm增加到3~4 mm,反映了混凝土本体而非表肤的抗冲磨性能,更能反映实际工况下C40以上高强抗冲磨混凝土的磨损速度。In order to properly evaluate the abrasion resistance of high-strength concrete for hydraulic outlet structures under high-speed flow with bed load, a new test method,the high-speed underwater method, was developed by the modification of the underwater method in Chinese standard DL/T 5150 ＂Test Specification for Hydraulic Concrete＂.Test parameters were studied including the rate of flow, the duration time of abrasion, the ratio of the total projection area of steel balls to that of the surface area of specimen, and the maximum size of steel balls, and the grading of steel balls, was optimized through the uniform design method with constraints.The test parameters of the new method were decided as follows：rotation speed of the agitation paddle 4 000 r/rain, velocity of bottom water 3.8 m/s, the total projection area ratio 50%, maximum size of steel balls 30 mm, grading of steel balls 8Φ30 mm, 17Φ25.4 rnm, 33Φ19.1 mm, 62Φ 12.5 mm, and duration time of abrasion 48 h.The efficiency and applicability of the standard and new methods were compared by the abrasion test of C^050 and C^60 pumped and normal consistency concrete, Compared with the standard method, the efficiency of the new method is increased by 3-4 times, the duration time of abrasion shorten by one third, the average abrasion depth increased from 1-2 mm to 3-4 mm, and the abrasion resistance characterized of the bulk concrete instead of the skin concrete.The new method is more suitable to simulate the in-situ abrasion speed of the concrete with strength grade C40 and above. Key words： high speed underwater method;abrasion test;bed load;high strength abrasion-resistant concrete

关 键 词：高速水下钢球法 抗冲磨试验 高强抗冲磨混凝土 推移质 

分 类 号：TU528.07[建筑科学—建筑技术科学]