再生骨料透水混凝土渗蓄性能与堵塞机理研究

Pervious concrete using recycled aggregate produced from construction and demolition waste helps to save resource and protect ecological environment, which has great economic benefits. However, the poor mechanical performance of pervious concrete together with significant decrease in permeability with service time and unclear clogging process, limit its wide application in practical engineering. To solve the above issues, several researches will be conducted as follows: The mix proportion is optimized based on orthogonal test of multi-design factors to improve the strength, permeability and durability of the pervious concrete simultaneously; A variety of micro-analysis techniques including CT is employed to establish the three-dimensional meso-scale model of pervious concrete which reflects its actual meso-structure characteristics; The three-dimensional model is further used to study the clogging process of pervious concrete under complex environment, and then the permeability damage model is built; A testing apparatus is designed for measuring permeability coefficient of pervious concrete considering actual service conditions. A service life prediction method of pervious concrete using recycled aggregate is proposed on the basis of site investigation. This project provides important theoretical basis and economic benefits for the comprehensive utilization of solid waste and the construction of sponge city.

将建筑废弃物作为再生骨料应用到透水混凝土中有利于节约资源，改善生态环境，具有良好的经济和生态效益，然而再生骨料透水混凝土的力学性能不佳、在服役过程中透水性能下降明显和堵塞机理尚未明确等问题成为制约其广泛应用的瓶颈。针对上述问题，本项目在以下几个方面展开研究：优化配合比设计，综合提升再生骨料透水混凝土的力学、透水和长期性能；借助CT扫描等微细观分析技术，建立反映真实再生骨料透水混凝土细观特征的三维模型，研究微细观特征对其宏观性能的影响机制；基于细观三维模型，探索各种复杂环境条件下的堵塞机制，建立混凝土的透水损伤模型；开发一种考虑实际服役环境对透水混凝土渗透性能影响的模拟测试装置，结合现场调查研究，提出再生骨料透水混凝土服役寿命评价方法。该项目研究成果将为固体废弃物的综合利用和海绵城市的建设提供重要的理论依据和实用价值。

将建筑废弃物作为再生骨料应用到透水混凝土中有利于节约自然资源，减少环境污染，改善生态环境，具有良好的经济效益和生态效益。针对目前透水混凝土性能设计方法准确性低、再生骨料透水混凝土力学性能较差和长期性能难以预测等问题，该项目进行了以下几个方面的研究：1）阐明了透水混凝土中水泥基体包覆再生骨料的形成模式，提出了一种透水混凝土细观结构预测方法，为透水混凝土宏观性能设计模型提供了基础；2）在综合考虑多种设计因素对透水混凝土性能影响的基础上，建立一种考虑骨料和水泥基体特性的透水混凝土性能设计模型；3）针对再生骨料和透水混凝土特性，提出了一种基于硅烷改性的再生骨料透水混凝土性能提升方法，在保证透水性能的前提下，可以有效提升透水混凝土的强度和抗冻性；4）从堵塞前-完全堵塞后-堵塞维护后三种状态下的孔隙结构出发，揭示了再生骨料透水混凝土透水性能劣化及维护机理，建立了一种考虑堵塞物固结的透水性能劣化模型。在该项目的资助下发表SCI检索论文13篇，核心研究成果发表在水泥基材料顶级期刊《Cem.Concr.Res.》；申请国家发明专利4项，授权发明专利2项；培养硕士研究生3名、博士研究生1名；参加国内外学术会议5次，做大会特邀报告1次；获黑龙江省自然科学一等奖1项、深圳市自然科学二等奖1项和日内瓦国际发明展银奖1项；获得2020年度国家自然科学杰出青年基金项目。