Wang Aoxuan, Fang Yuan, Zhou Yingwu, Wang Chenman, Dong Biqin, Chen Cheng
Key Laboratory for Resilient Infrastructures of Coastal Cities, Ministry of Education, Shenzhen University, Shenzhen 518060, China.
Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China.
Materials (Basel). 2022 May 25;15(11):3767. doi: 10.3390/ma15113767.
In the interest of solving the resource and environmental problems of the construction industry, low-carbon geopolymer coating ensures great durability and extends the service life of existing infrastructure. This paper presents a multidisciplinary assessment of the protective performance and environmental impacts of geopolymer coating. Various parameters, such as main substance, water-solid (W/S) ratio, activator type and curing time, were investigated for their effects on interface characterization in terms of contact angle, surface energy, mechanical properties and microstructure. These parameters had negligible effects on the amounts and types of hydrophilic functional groups of geopolymer surfaces. A combination of organic surface modifiers and geopolymer coatings was shown to ensure hydrophobic surface conditions and great durability. Silicon-based modifiers exhibited better wetting performance than capillary crystalline surfactants by eliminating hydroxyl groups and maintaining structural backbone Si-O-T (Si, Al) on geopolymers' surfaces. Finally, life-cycle analysis was conducted to investigate the environmental performance. Geopolymer coating yielded substantially lower environmental impacts (50-80% lower in most impact categories) than ordinary Portland cement (OPC) coating. Silicon-based modifiers had negligible influence due to their minimal usage. Increasing the W/S ratio diluted the geopolymer coating and decreased the environmental impacts, and slag-based geopolymer coating achieved lower environmental impacts than FA-based and MK-based varietie.
为了解决建筑业的资源和环境问题，低碳地质聚合物涂层具有出色的耐久性，可延长现有基础设施的使用寿命。本文对地质聚合物涂层的防护性能和环境影响进行了多学科评估。研究了各种参数，如主要物质、水固比（W/S）、活化剂类型和养护时间，考察它们对接触角、表面能、力学性能和微观结构等界面特性的影响。这些参数对地质聚合物表面亲水性官能团的数量和类型影响可忽略不计。有机表面改性剂与地质聚合物涂层相结合可确保疏水表面条件和出色的耐久性。硅基改性剂通过消除羟基并保持地质聚合物表面的结构主链Si-O-T（Si，Al），表现出比毛细管结晶表面活性剂更好的润湿性能。最后，进行生命周期分析以研究环境性能。与普通硅酸盐水泥（OPC）涂层相比，地质聚合物涂层产生的环境影响显著更低（在大多数影响类别中低50-80%）。由于硅基改性剂用量极少，其影响可忽略不计。提高水固比会稀释地质聚合物涂层并降低环境影响，矿渣基地质聚合物涂层的环境影响低于粉煤灰基和偏高岭土基品种。
