可再生废弃骨料混凝土超声回弹测强曲线试验研究  

Experimental Study on Ultrasonic Rebound Strength Measurement Curve of Renewable Waste Aggregate Concrete

作　　者：程志敏 CHENG Zhimin(China Railway Construction Group Co.Ltd.,Beijing 100040,China)

机构地区：[1]中铁建设集团有限公司,北京100040

出　　处：《铁道建筑技术》2022年第6期1-4,68,共5页Railway Construction Technology

基　　金：中铁建设集团有限公司科研计划项目(HB21-35)。

摘　　要：可再生废弃骨料混凝土在实际工程应用日趋广泛,其与普通混凝土力学性能差异明显,将普通混凝土测强曲线直接应用于可再生废弃骨料混凝土并不合理。可再生废弃骨料混凝土强度如果得不到准确预测,就难以保证可再生废弃骨料混凝土工程质量。基于此,本文对不同强度等级(C30、C35)、不同龄期(7 d、14 d和28 d)的可再生废弃骨料混凝土试块进行超声回弹综合试验。基于试验结果,建立可再生废弃骨料混凝土专用测强曲线,并对测强曲线准确性进行分析。研究结果表明:随养护龄期增长,可再生废弃骨料混凝土试块返弹值、超声音速值和抗压强度值均呈现上扬趋势,抗压强度增长速度最快、超声音速增速最小;C30、C35可再生废弃骨料混凝土测强曲线不同,不能使用同一测强曲线预测不同强度等级可再生废弃骨料混凝土抗压强度。Renewable waste aggregate concrete is increasingly widely used in practical projects of civil engineering.The mechanical properties of recycled waste aggregate concrete and ordinary concrete are obviously different.It is unreasonable to directly apply the strength measurement curve of ordinary concrete to renewable waste aggregate concrete.It is difficult to guarantee the recycled waste aggregate concrete’s quality if the strength of recycled waste aggregate concrete can not be accurately predicted.According to the above problems,the ultrasonic rebound comprehensive tests were carried out on recycled waste aggregate concrete test blocks with different strength grades(C30,C35)and different ages(7 days,14 days and 28 days).Based on the test results,the special strength measurement curve of renewable waste aggregate concrete was established,and the accuracy of the special strength measurement curve was analyzed.Research results show that with the increase of age,the rebound value,ultrasonic sound speed value and compressive performance value of recycled aggregate concrete test block show an upward trend,in which the compressive performance increases the most,while the ultrasonic sound speed increases the least.The strength measurement curves of C30 and C35 recycled concrete are different.The same strength measurement curve cannot be used to predict the compressive strength of recycled concrete with different strength grades.

关 键 词：可再生废弃骨料混凝土 超声回弹 测强曲线 试验 

分 类 号：TU502.6[建筑科学—建筑技术科学] TU528.041