冲击回波主频对箱梁预应力孔道注浆饱满度的响应及应用

通过用冲击回波法比较箱梁在不同注浆饱满度下冲击回波信号的主频,研究主频对不同注浆饱满度的响应规律和无浆孔道的判断依据。根据不同类型测区的试验数据,总结出全空孔道箱梁的主频经验方程。依据实测主频对这些测区进行成像,通过比较实测主频和同等情况下全空管道的理论主频,判断孔道的注浆质量。最终判定4个测区的注浆有缺陷,凿开后验证为空洞,并给出了相应的照片。研究结果表明,冲击回波主频可以有效地评价箱梁预应力孔道的注浆饱满情况。

Impact-echo Characteristic Frequencies Response to Grouting Fullness in Ducts of Prestressed Box Beam and Application

As a new elastic wave method,the impact-echo method(IEM) was applied to evaluate the grouting fullness in ducts of prestressed box beam.By comparing the characteristic frequencies of different grouting fullnesses in ducts by IEM,the variation of the characteristic frequencies and the judgment of the voids in ducts were researched.On the basis of experimental data of each test area,an empirical formula of calculating characteristic frequencies of concrete deck of box beam with voids in ducts was created.Then...