Study of the Durability Damage of Ultrahigh Toughness Fiber Concrete Based on Grayscale Prediction and the Weibull Model

Abstract

The purpose of this research is to investigate the durability damage law for ultrahigh toughness cementitious composites (UHTCCs) under freeze–thaw environments and impact resistance. In this study, UHTCCs with fiber length-to-diameter ratios of 5/30, 8/30, 12/20, 12/30 and 12/48 were tested for impact resistance and freeze–thaw cycles. The freeze–thaw cycle process and impact resistance process for UHTCC are comprehensively analyzed and evaluated in terms of mass loss, compressive strength loss, relative dynamic elastic modulus loss and impact resistance number. The freeze–thaw damage prediction model for the relative dynamic elastic modulus of the UHTCC is established based on the regularity of the measured data for the relative dynamic elastic modulus of UHTCC and also on the GM(1,1) power model. The accuracy and reliability of the GM(1,1) power model is analyzed using the relative error, absolute correlation degree, mean variance and probability of small errors. According to the evolution law of the impact resistance number of the UHTCC, the impact damage prediction model for UHTCC is established based on the Weibull distribution model, and the accuracy of the model is analyzed by using the decision coefficient R2. The results show that UHTCC has high durability performance, and the durability performance of UHTCC at a length-diameter ratio of 12/48 is optimal. The freeze–thaw damage evolution model and impact damage evolution model established in this research are sufficiently realistic, the average relative error of the GM(1,1) power model is less than 5%, and the coefficient of determination R2 of the Weibull distribution model is greater than 0.93, which effectively reflects the damage development process for concrete under freeze–thaw and impact environment with high fitting accuracy.

Experimental Study on the Durability Performance of Sustainable Mortar with Partial Replacement of Natural Aggregates by Fiber-Reinforced Agricultural Waste Walnut Shells

“…This phase is characterized by a steeper damage curve, indicating a considerable increase in damage to the cement mortar. Eventually, as D(N) reaches 1, the curve tends to smooth, indicating complete destruction of the cement mortar [45,62,63]. ) . ]…”

Damage Model of Carbon-Fiber-Reinforced Concrete Based on Energy Conversion Principle

“…Approaching the interior of concrete as an innumerable composition of microelements, the degree of damage can be expressed by the ratio of the value of microelements destroyed by damage, N, to the value of microelements destroyed by damage, M, and the value of damage-destroyed microelements is related to the energy dissipation during the damage process. Since the two-parameter WEIBULL probability distribution has been applied to the analysis of concrete volume rupture and failure data, this article assumes that the dissipation energy of CFRC follows the two-parameter WEIBULL probability density function [29]:…”

Under Sulfate Dry–Wet Cycling: Exploring the Symmetry of the Mechanical Performance Trend and Grey Prediction of Lightweight Aggregate Concrete with Silica Powder Content

“…The grey model is a method utilized for analyzing and predicting systems characterized by uncertain information, and it can accurately predict target performance based on a small amount of critical information. It holds significant practical value in predicting and preventing concrete damage [38,39]. Yongli et al, established a prediction model for the flexural tensile strength and compressive strength of concrete based on pore characteristic parameters that can accurately predict the mechanical properties of concrete [40].…”