超声波在新拌液态粉煤灰抗压强度研究中的应用

Application of Ultrasonic Waves in the Study of Compressive Strength of Freshly Mixed Liquid Fly Ash

对掺石灰的一种新型液态粉煤灰材料进行无侧限抗压强度检测,通过试验研究石灰含量变化对试件抗压强度的影响,试验结果表明:当石灰含量为0、4%、8%和12%时,新拌液态粉煤灰的7 d和28 d抗压强度均逐渐增加,尤其是28 d时的强度显著大于7 d时的强度。利用超声波无损检测技术测得试件的超声波速,通过回归分析研究抗压强度与超声波波速之间的相关性,建立了二者不同龄期的理论关系式:7 d龄期的宜采用二次函数拟合,回归方程为f_(cu)=0.000000976692v^(2)-0.000830792v+0.45616;28 d龄期的宜采用一次函数拟合,回归方程为f_(cu)=0.002v-0.96639;整体实测数据关系宜采用二次函数拟合,回归方程为f_(cu)=0.00000117211v^(2)-0.000767908v+0.32397。7 d和28 d的相关性R^(2)均>85%,表明其抗压强度和超声波速度之间存在显著的相关性,为研究新拌液态粉煤灰的无损检测提供了理论基础。

Unconfined compressive strength testing is conducted on a new type of liquid fly ash material mixed with lime.The influence of lime content changes on the compressive strength of specimens is studied through tests.The results show that when the lime content is 0,4%,8%,and 12%,the compressive strength of freshly mixed liquid fly ash gradually increased at 7 days and 28 days,especially the strength at 28 days is significantly greater than that of 7 days.The ultrasonic wave velocity of the specimen is measured by ultrasonic non-destructive testing technology,and the correlation between compressive strength and ultrasonic wave velocity is studied by regression analysis.The theoretical relationship between the two at different ages is established:for the 7 days age,a quadratic function should be used for fitting,and the regression equation is f_(cu)=0.000000976692 v^(2)-0.000830792 v+0.45616.At 28 days age,a linear function should be used for fitting,and the regression equation is f_(cu)=0.002 v-0.96639.The overall measured data relationship should be fitted with a quadratic function,and the regression equation is f_(cu)=0.00000117211 v^(2)-0.000767908 v+0.32397.The correlation R^(2)of 7 days and 28 days is both greater than 85%,indicating that a significant correlation between compressive strength and ultrasonic velocity.The research provides a theoretical basis for the non-destructive testing of fresh liquid fly ash.