This study analysed the fine particle (<5 mm) waste generated during siliceous or calcareous (depending on the composition of the original aggregate) concrete waste crushing. In the absence of industrial applications, such waste is amassed in open-air stockpiles on construction and demolition wastes (CDW) management plant grounds. The aim pursued was to find an outlet for that material in the cement industry. The starting waste, sourced from six Spanish management facilities, was characterised for its chemical and mineralogical composition, physical properties and pozzolanicity. The mineralogical phases in the CDW/lime system and their variations during the pozzolanic reaction were likewise identified. The findings showed that the fine waste consisted primarily in quartz, calcite, micas and feldspars, with smaller fractions of kaolinite and cement anhydrous phases. No portland cement hydration phases were identified. All six types analysed exhibited medium to low pozzolanicity, with the highest values recorded for the siliceous waste. Ettringite, C–S–H gels and calcium aluminate hydrates (C₄AH_13, C₄AcH₁₂) were identified during the pozzolanic reaction in CDW/lime system. Therefore, this type of waste can be reused as supplementary cementitious material with low-medium pozzolanic activity.

中文翻译：

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CDW细级分的多技术表征和CDW /石灰系统中反应性的评估

这项研究分析了在硅质或钙质（取决于原始集料的成分）混凝土废物粉碎过程中产生的细颗粒（<5毫米）废物。在没有工业应用的情况下，此类废物会聚集在建筑和拆迁废物（CDW）管理工厂的露天露天仓库中。追求的目标是在水泥工业中找到这种材料的出口。来自西班牙六个管理机构的原始废物以其化学和矿物组成，物理性质和火山灰性为特征。同样确定了CDW /石灰系统中的矿物相及其在火山灰反应期间的变化。研究结果显示，这些细小废物主要包括石英，方解石，云母和长石，含有较少比例的高岭石和水泥无水相。没有发现波特兰水泥水化阶段。分析的所有六种类型均表现出中等至低的火山灰性，其中硅质废物的记录值最高。钙矾石，C–S–H凝胶和铝酸钙水合物（C在CDW /石灰体系中的火山灰反应期间鉴定出₄ AH _13， C ₄ AcH ₁₂）。因此，这种废物可以作为具有低中火山灰活性的补充胶结材料再利用。