基于灰靶决策对BFCC力学性能及抗渗性能的评估

Evaluation of Permeability and Mechanical Properties of BFCC Basedon Gray Target Decision

试验研究了不同纤维长度和不同应力比条件下BFCC抗压强度及抗渗性能的变化规律,运用灰色系统理论对BFCC的抗压强度、电通量与孔结构参数进行灰色关联分析,运用多目标加权灰靶决策模型对不同应力比下的BFCC综合性能进行评估。研究表明:随纤维长度增加,BFCC抗压强度先增加后降低,BFCC电通量值持续减小;相同应力比条件下,延长养护龄期,BFCC的抗压强度增加,电通量值减小;养护龄期相同时,增加应力比,BFCC电通量值先减小后增大,且在应力比为0.2时为最小,而其抗压强度则呈持续减小的趋势。根据灰色关联分析结果,采用气泡间距系数从微观角度表征抗压强度的变化,采用气泡比表面积表征电通量的变化,运用多目标加权灰靶决策模型定量评估不同应力比下BFCC的综合性能,随应力比不断增大,BFCC相对综合性能指标不断减小,且其综合性能不断劣化。

The compressive strength and impervious performance change rules of BFCC under different curing ages and different stress ratios are studied in this paper.Grey system theory is used to analyze the grey correlation of BFCC compressive strength,electric flux and pore structure parameters.The multi-objective weighted grey target decision model is used to evaluate the comprehensive performance of BFCC under different stress ratios.The results show that the compressive strength of BFCC increases first and then decreases with the increase of fiber length,and the electrical flux value of BFCC decreases continuously.Under the condition of the same stress ratio,the compressive strength of BFCC is increased and the electric flux is decreased when the curing period is prolonged.At the same curing age,when the stress ratio increases,the value of BFCC power flux first decreases and then increases,and it is the smallest when the stress ratio is 0.2,while the compressive strength continues to decrease.According to the results of grey correlation analysis,the bubble spacing coefficient was used to indicate the change of compressive strength and the specific surface area of the bubble was used to represent the change of electric flux.The multi-objective weighted grey target decision model is used to quantitatively evaluate the comprehensive performance of BFCC under different stress ratios.As the stress ratio increases,the relative comprehensive performance index of BFCC decreases and its comprehensive performance deteriorates.