基于孔隙结构特征的透水混凝土性能评价与分析

Evaluation and Analysis of Pervious Concrete Performance Based on Pore Structure Characterization

为探究不同因素对透水混凝土力学性能、透水性能和孔隙特征的影响,选择了水胶比、集灰比、粉煤灰掺量、煤矸石掺量4个因素,采用单因素试验方法研究了各因素在不同水平下对透水混凝土(EPC)性能的影响;利用图像分析法对混凝土内部孔隙特征进行量化分析,并建立EPC的透水系数模型和抗压强度模型;利用熵权法结合灰色关联理论对EPC性能的影响因素进行了综合评价。结果表明:EPC的抗压强度与劈裂抗拉强度基本满足正相关的关系,通过数值拟合发现,其满足一定的函数关系;粉煤灰掺量系列的透水混凝土具有相对较高的拉压比,表明粉煤灰能有效改善EPC韧性;等效孔径可用作特征孔径,根据孔隙特征和总浆体面积分别建立了EPC的透水系数模型和抗压强度模型;煤矸石掺量系列的EPC关联度相对较高,当煤矸石掺量为60%时,综合评价最高,关联度为89.56%。

To explore the effects of different factors on the mechanical properties,permeability,and pore characteristics of pervious concrete(EPC),four factors of water-cement ratio,aggregate-to-cement ratio,fly ash content,and gangue content were chosen.A single-factor experimental method was adopted to study the influence of each factor at varying levels on EPC performance.The internal pore characteristics of the concrete were quantified using IPP image analysis.Models for the permeability coefficient and compressive strength of EPC were established.The entropy weight method combined with grey correlation theory was utilized for a comprehensive evaluation of the influencing factors on EPC performance.It is found that the compressive strength and splitting tensile strength of EPC are positively correlated,fitting a specific functional relationship.The F of EPC demonstrated a relatively high tensile-to-compressive strength ratio,indicating that fly ash effectively improves EPC toughness.The equivalent pore size was identified as a characteristic pore size.Based on pore characteristics and total slurry area,models for the permeability coefficient and compressive strength of EPC were developed.The M of EPC showed a relatively high correlation,with the highest comprehensive evaluation score of 89.56%when the coal gangue content was 60%.