表面改性硅/铝质材料及其在水泥基材料中应用的研究进展

Research Progress on Surface Modification of Silicon-Aluminum Materials and Their Applications in Cement-based Materials

水泥基材料是工程建设中必不可少的材料,其生产带来的环境和资源消耗问题逐渐被广泛关注。同时,工业废弃物的产量逐年增加,其引起的环境污染问题也愈发严重。从环保及可持续发展角度考虑,可将硅/铝质工业废弃物用于水泥基材料中,此举可同时解决水泥熟料生产和工业废弃物排放造成的环境问题。但部分硅/铝质工业废弃物由于活性相对较低,大量使用会导致水泥基材料早期强度较低,限制了其在水泥基材料中的掺量。超细硅/铝质材料极易团聚,导致其性能不能得到充分发挥,从而影响了硅/铝质材料在水泥基材料中的高效利用。现代水泥混凝土的性能不再仅以力学性能作为评判标准,良好的工作性、耐久性和功能性也是其发展趋势。此外,功能材料如何与水泥基材料结合才能更好地发挥其功能性也是目前水泥混凝土领域研究的热点。采用表面改性技术对硅/铝质材料性能进行改善已取得了较好的效果。对一些惰性或活性较低的硅/铝质工业废弃物进行必要的改性,可在一定程度上提高其活性,缓解其作为掺合料使用带来的水泥基材料早期强度低的问题,同时还可增加其在水泥基材料中的掺量,提升工业废弃物的综合利用率。酸碱微腐蚀表面改性和增钙煅烧表面改性等技术是提升硅/铝质材料(粉煤灰、石英砂尾矿等)活性常用的方法。功能外加剂表面改性可改善超细硅/铝质材料的团聚现象,提高其在水泥基材料中的分散性。而分散性的提高使硅/铝质材料在水泥基材料中性能发挥更充分,同时改善水泥基材料的工作性能。颗粒负载表面改性是将具有环境清洁功能的材料负载在硅/铝质材料的表面,在满足掺合料基本性能的同时,还能起到治理环境的作用。硅/铝质工业废弃物的改性利用将获得“以污治污”双重环境效益。本文综述了利用表面改性技术提升硅/铝质材料活性、分散性和功能性的研究进展,提出了表面改性技术在水泥基材料应用中存在的问题,以期为硅/铝质工业废弃物的高效利用提供参考性建议。

Cement-based materials are indispensable materials in engineering construction,but the problems of environment and resource consumption caused by their production have been paid more and more attention.Meanwhile the output of industrial wastes is increasing year by year,and the environmental pollution caused by industrial wastes is becoming more and more serious.Considering environmental protection and sustainable development,silicon-aluminium industrial wastes can be used in cement-based materials.This approach can solve the environmental problems caused by the production of cement clinker and the emissions of industrial wastes at the same time.However,the lower activity of some silicon-aluminium industrial wastes used extensively in cement concrete will reduce the early strength of cement-based materials and also limit their utilization.The properties of ultrafine silicon-aluminium materials are not fully released due to their agglomeration and poor dispersivity,which will affect the efficient use of silicon-aluminium materials in cement-based materials.The performances of modern cement concrete are no longer only judged by the mechanical properties,and good workability,durability and functionality are its trend to develop.Finding ways to combine functional materials with cement-based materials in order to better play their functions is also one of the research hotspots in the field of cement concrete.Surface modification technologies have achieved good results in improving the properties of silicon-aluminium materials.The modification of some inert or less active silicon-aluminium industrial wastes can improve their activity on a degree,and reduce the decline of early strength of cement-based materials caused by their use as admixtures,which can also increase their quantities used in cement-based materials and improve the comprehensive utilization of industrial wastes.The technologies of surface modification including acid-base micro-corrosion and calcined with calcareous materials are common methods to improve the activity of silicon-aluminium materials(fly ash,quartz sand tailings,etc.).Surface modification by using functional additives can reduce the agglomeration of ultrafine silicon-aluminium materials and increase their dispersivity in cement-based materials,which can make the properties of silicon-aluminium materials develop more fully and improve the workability of cement-based materials.Loading materials with environmental cleaning function on the surface of silicon-aluminium materials can not only meet the basic properties of admixtures,but also play a role in protecting environment,and the utilization of silicon-aluminium industrial wastes modified by surface modification technologies will play a dual environmental benefit of“treating pollution by using wastes”.This paper summarizes the research progress on improving the properties of silicon-aluminium materials include activity,dispersivity and functionality by using the technologies of surface modification.Some problems still exist in the application of surface modification technologies in cement-based materials are put forward in order to provide reference suggestions for the efficient utilization of industrial wastes.