Zhang Bo, Li Qingbin, Ma Rui, Niu Xujing, Yang Lin, Hu Yu, Zhang Jinliang
State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing 100084, China.
Yellow River Engineering Consulting Co., Ltd., Zhengzhou 450003, China.
Materials (Basel). 2021 Jan 28;14(3):609. doi: 10.3390/ma14030609.
In high humidity areas, it is necessary to improve the impermeability of concrete to water and other erosion solutions. The internal defect and pore channel of concrete are the main factors affecting the impermeability and durability. In this paper, a novel hydrophobic agent named Yellow River Engineering Consulting (YREC) was prepared. The relative internal defect degree of concrete with different curing ages and YREC contents was evaluated by ultrasonic non-destructive testing as qualitative characterization method, and the effect of YREC on hydration reaction was investigates using X-ray powder diffraction (XRD). Water permeability and contact angle tests were used to analyze the internal and external hydrophobicity induced by YREC addition, respectively. The pore structure changes of concrete mortar matrix induced by YREC were further discussed applying low-temperature liquid nitrogen adsorption (LT-NA) and mercury intrusion/extrusion porosimetry (MIP). The results indicated that YREC not only improves the impermeability of water, but also greatly enhances the mechanical strength. In the case of mixing YREC, the porosity of concrete mortar matrix decreases accompanied with the more advantage pores (micropores and transition pores) developed. Based on the relative internal defect degree and the changes of multi-scale pore structure, the functionality and durability of concrete with 4% YREC addition are the most desirable.
在高湿度地区，有必要提高混凝土对水和其他侵蚀性溶液的抗渗性。混凝土的内部缺陷和孔隙通道是影响其抗渗性和耐久性的主要因素。本文制备了一种名为黄河工程咨询（YREC）的新型疏水剂。采用超声无损检测作为定性表征方法，评估了不同养护龄期和YREC含量的混凝土的相对内部缺陷程度，并利用X射线粉末衍射（XRD）研究了YREC对水化反应的影响。分别采用透水试验和接触角试验分析了添加YREC引起的内部和外部疏水性。应用低温液氮吸附（LT-NA）和压汞/退汞孔隙率测定法（MIP）进一步探讨了YREC引起的混凝土砂浆基体孔隙结构变化。结果表明，YREC不仅提高了混凝土的抗渗性，而且大大提高了其力学强度。在掺入YREC的情况下，混凝土砂浆基体的孔隙率降低，同时更多的优势孔隙（微孔和过渡孔）得以发展。基于相对内部缺陷程度和多尺度孔隙结构变化，添加4%YREC的混凝土的功能性和耐久性最为理想。
