Abstract

The present work developed a thermal insulating coating/plastering mortar from the complete replacement of the natural aggregate by friable quartzite (QTZ), with the addition of steelmaking slag powder (SSP). Despite having promising characteristics, no studies so far have taken advantage of the thermal insulating properties of the SSP. Initially, the QTZ and PEA were characterized according to physical, chemical, mineralogical, and morphological analyses. The mortars were prepared with Portland cement, hydrated lime, air-entraining admixtures (AEA), fine aggregates, and SSP. Four mixes were produced: (1) reference (REF) (with natural sand); (2) QTZ + AEA (NO SSP); (3) QTZ + AEA + 5%SSP, and (4) QTZ + AEA + 10%SSP. The following tests were carried out: flow, water retention, specific gravity (density), water absorption by immersion and by capillarity, flexural strength, compressive strength, adhesive strength, UPV, morphology, shrinkage, thermal conductivity, specific heat, and potential of environmental contamination. As result, the QTZ presented physical characteristics similar to those of the natural aggregate, except for the high content of powdery material. The mortar with 5% SSP had the lowest thermal conductivity (56% lower than REF) and the highest specific heat (37% higher than REF). The SSP’s mineralogical composition and resulting pore system were the most influential factors for these properties. Therefore, the SSP can be considered a “thermal insulating admixture” and the use of these residues is technically feasible to improve the thermal performance of buildings.

中文翻译：

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含有采矿和钢铁残渣的隔热涂料砂浆以及“隔热外加剂”的提议

摘要

目前的工作是用易碎石英岩（QTZ）完全替代天然骨料，并添加炼钢矿渣粉（SSP），开发出一种隔热涂料/抹灰砂浆。尽管具有很有前途的特性，但迄今为止还没有研究利用 SSP 的隔热特性。最初，根据物理、化学、矿物学和形态分析对 QTZ 和 PEA 进行了表征。砂浆由波特兰水泥、熟石灰、引气剂（AEA）、细骨料和过磷酸钙配制而成。生产了四种混合物：（1）参考（REF）（使用天然砂）；(2) QTZ + AEA（无 SSP）；(3)QTZ+AEA+5%SSP，(4)QTZ+AEA+10%SSP。进行了以下测试：流动性、保水性、比重（密度）、浸没吸水率和毛细管吸水率、弯曲强度、压缩强度、粘合强度、UPV、形态、收缩率、导热率、比热和电势。环境污染。结果，除了粉状材料含量高之外，QTZ 呈现出与天然骨料相似的物理特性。添加5%SSP的砂浆导热系数最低（比REF低56%），比热最高（比REF高37%）。SSP 的矿物学成分和由此产生的孔隙系统是对这些特性影响最大的因素。因此，过磷酸钙可以被认为是一种“隔热外加剂”，利用这些残留物来改善建筑物的热工性能在技术上是可行的。