The thermal conductivity of construction materials is among the main factors influencing the thermal performance of buildings. This property is, thus, extensively demanded for design purposes. The thermal conductivity is especially related to the pore system and the composition of cement-based composites, the same factors that affect their Ultrasonic Pulse Velocity (UPV). In this sense, the present work evaluates the correlation between thermal conductivity and UPV. To this purpose, mortar specimens were investigated, with varying mix proportions, fine aggregate types, and dosages of air-entraining admixture. A satisfactory determination coefficient (R 2 > 0.9) was obtained between thermal conductivity and UPV of the mortars when they were grouped under similar components and pore structure. It was observed that the pore system of the mortars tested is more influential to the UPV than their overall porosity. In this sense, a better correlation was found between UPV and thermal conductivity than between thermal conductivity and specific gravity. Additionally, the fine aggregate type presents a significant impact—not only due to its chemical and mineralogical properties but also as a result of the morphology that each aggregate generates within the matrix. In conclusion, this technique potentially presents high applicability to the thermal characterisation of cement-based composites.

中文翻译：

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水泥基复合材料超声脉冲速度与热导率的相关性

建筑材料的导热系数是影响建筑物热性能的主要因素之一。因此，出于设计目的，广泛需要这种特性。导热系数尤其与孔隙系统和水泥基复合材料的成分有关，这些因素影响其超声波脉冲速度 (UPV)。从这个意义上说，目前的工作评估了热导率和 UPV 之间的相关性。为此，研究了具有不同混合比例、细骨料类型和加气外加剂剂量的砂浆试样。当砂浆在相似的组分和孔隙结构下分组时，它们的热导率和 UPV 之间获得了令人满意的决定系数（R 2 > 0.9）。据观察，所测试砂浆的孔隙系统对 UPV 的影响比其整体孔隙率更大。从这个意义上说，UPV 与热导率之间的相关性比热导率与比重之间的相关性更好。此外，细骨料类型具有显着影响——不仅是由于其化学和矿物学特性，还因为每个骨料在基质内产生的形态。总之，该技术可能对水泥基复合材料的热表征具有很高的适用性。细骨料类型具有显着影响——不仅是由于其化学和矿物学特性，而且还因为每个骨料在基质中产生的形态。总之，该技术可能对水泥基复合材料的热表征具有很高的适用性。细骨料类型具有显着影响——不仅是由于其化学和矿物学特性，而且还因为每个骨料在基质中产生的形态。总之，该技术可能对水泥基复合材料的热表征具有很高的适用性。