钢纤维混凝土超声-回弹测强曲线的建立

结合厦门至昆明国家重点公路干线的施工情况，配制一批不同龄期的掺入粉煤灰、矿渣的C40钢纤维混凝土试件。通过超声波检测、回弹检测及抗压强度实验，分析钢纤维掺量对钢纤维混凝土超声波声速、回弹值和抗压强度的影响。根据实验数据，建立钢纤维混凝土抗压强度、超声波声速、回弹值之间的关系曲线。结果表明：随着钢纤维掺量的增加，三种钢纤维混凝土的超声波声速、回弹值、抗压强度均呈先增大后减小的趋势；掺入粉煤灰和矿渣的混凝土密实度提高；铜纤维混凝土抗压强度、声速、回弹值三者之间相关性较好，超声-回弹综合法用于钢纤维混凝土无损检测是可行的。

Establishment of ultrasonic-rebound curve in steel fiber concrete

This paper introduces the preparation of a number of C40 steel fiber reinforced concrete specimens, incorporated with fly ash and slag at different ages, combined with the construction of the state key highway from Xiamen to Kunming, the analysis of the influence of steel fiber content ultrasonic velocity, rebound value and compression strength steel fiber reinforced concrete by ultrasonic detection, rebound detection, and compression strength test, and the development of relationship curve between compression strength, ultrasonic velocity, rebound value of steel fiber reinforced concrete by regression analysis of the experimental data. The results show that the increasing dosage of steel fiber generates a tendency to increase followed by decrease in ultrasonic velocity, rebound value and compression strength of three kinds of steel fiber reinforced concrete; reinforced concrete incorporated with fly ash and slag exhibits increased compactness; a better correlation occurs between the ultrasonic velocity, rebound value, and compression strength. This ultrasonic-rebound detection method may have a more practical application in non-destructive testing of steel fiber reinforced concrete.