Thermal mortars are a trend in the construction industry in recent years, owing to the required decrease of the thermal transmission of building envelopes. The high porosity of thermal mortars leads to permeability values that can affect their durability since it creates more favourable conditions for the penetration of aggressive agents. Water is observed as one of the most common and harmful degradation agents. Regarding the climatic variability in Europe, freezing is a usual degradation mechanism both in severe and moderate climates. Since thermal mortars have higher water absorption than a common insulation, the freezing may occur. As no durability assessment methodologies to evaluate the exposure of thermal mortars to freezing degradation mechanisms exist, the present work has the objective to analyse existing accelerated ageing procedures, which envisage freezing degradation mechanism. As such, the durability assessment described in EN 1015-21 and ETAG 004 was adapted and implemented in different thermal mortars. It was observed that the higher number of cycles and the severity of the freeze–thaw ageing cycles, according to ETAG 004, may reproduce the effect of the northern European climates, while the ageing cycles, described in EN 1015-21, combine degradation mechanisms that occur in central and southern European climates. This adaptation allowed collecting reliable data and inputs to the development of durability assessment methodologies directly applicable to thermal rendering and plastering systems.

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热砂浆冷冻耐久性试验方法的评估

由于需要降低建筑围护结构的热传导，热砂浆是近年来建筑行业的一种趋势。热砂浆的高孔隙率导致渗透率值会影响其耐久性，因为它为侵蚀剂的渗透创造了更有利的条件。水被认为是最常见和最有害的降解剂之一。关于欧洲的气候变化，结冰是严重和温和气候下的常见退化机制。由于热砂浆的吸水率高于普通绝缘材料，因此可能会发生冻结。由于没有耐久性评估方法来评估热砂浆在冷冻降解机制下的暴露情况，目前的工作目标是分析现有的加速老化程序，其中设想了冷冻降解机制。因此，EN 1015-21 和 ETAG 004 中描述的耐久性评估在不同的热砂浆中进行了调整和实施。据观察，根据 ETAG 004，较高的循环次数和冻融老化循环的严重程度可能会重现北欧气候的影响，而 EN 1015-21 中描述的老化循环结合了降解机制发生在欧洲中部和南部的气候中。这种适应允许收集可靠的数据和输入，以开发直接适用于热渲染和抹灰系统的耐久性评估方法。据观察，根据 ETAG 004，较高的循环次数和冻融老化循环的严重程度可能会重现北欧气候的影响，而 EN 1015-21 中描述的老化循环结合了降解机制发生在欧洲中部和南部的气候中。这种适应允许收集可靠的数据和输入，以开发直接适用于热渲染和抹灰系统的耐久性评估方法。据观察，根据 ETAG 004，较高的循环次数和冻融老化循环的严重程度可能会再现北欧气候的影响，而 EN 1015-21 中描述的老化循环结合了降解机制发生在欧洲中部和南部的气候中。这种适应允许收集可靠的数据和输入，以开发直接适用于热渲染和抹灰系统的耐久性评估方法。