Influence of fiber size effect on mechanical properties of deep shaft linerconcrete
To explore the impact of fiber size effect on the mechanical properties and strain evolution of deep shaft liner steel fiber reinforced concrete,three concrete formulations with different steel fiber sizes and admixtures were designed.After testing the sampl's tensile and compressive mechanical properties,it was found that with the increase of steel fiber size and admixtures,the uniaxial compressive strength,tensile strength,flexural strength,and elastic modulus of the samples increased.Using non-contact digital image correlation technology to monitor the damage process of the sample,it was found that the addition of steel fibers significantly increased the number and length of surface cracks when the sample was damaged,compared to plain concrete samples.With the increase in the size of steel fibers,the width of surface cracks decreased when the sample was damaged,and the axial deformation of the concrete sample decreased.When the sample reaches the peak load,the plain concrete loses its stability quickly and is damged,while the steel fiber concrete sample still has a certain residual strength when it reaches the peak load.Then,the random forest model is used to train,test,and predict the testing strength of steel fiber concrete.The results show that the training,testing,and prediction accuracy of the samples is high,with the R2＞0.8,and the root mean square error value is small.This indicates that the improved random forest model is more accurate in predicting the strength of steel fiber concrete.Using this prediction model,the labor and material costs required for optimizing the steel fiber concrete formula can be greatly reduced,it can provide a reference for predicting the strength of concrete formulations in on-site application.
万方数据
维普
