The environmental impact reduction has a growing prominence in building constructions. One of the solutions to that is external wall coating mortars with improved thermal performance, which can be produced with incorporation of lightweight aggregates. To obtain a mortar with the demanded hardened characteristics (physical and mechanical), their fresh properties must be acceptable. This study is focused on the fresh state properties of mortars with improved thermal performance. The mixes were produced with incorporation of different lightweight aggregates (expanded clay, expanded cork granules), a main binder (cement), supplementary materials as partial replacement of cement (fly ash, air lime) and admixtures (air entraining agent, water retaining agent). In this paper, the selected mortars with acceptable workability were tested for fresh density, flow, air content, and water retention. Lastly, the relationship between the fresh and hardened properties (obtained from a previous study) was assessed to highlight the importance of fresh properties. In conclusion, the mortars’ fresh behaviour was mainly influenced by the incorporation of different lightweight aggregates and admixtures. In addition, an optimization was carried out to select the most adequate thermal mortars for the external wall coatings from two perspectives, namely the overall performance (fresh properties, compressive strength, capillary water absorption, thermal conductivity) and the individual thermal performance.

减少环境影响在建筑中的地位越来越重要。解决方案之一是具有改善的热性能的外墙涂料砂浆，可以通过掺入轻质骨料来生产。为了获得具有所需硬化特性（物理和机械特性）的砂浆，其新鲜性能必须可以接受。这项研究的重点是具有改善的热性能的砂浆的新鲜状态性能。这些混合物是通过掺入不同的轻质骨料（膨胀的粘土，膨胀的软木颗粒），主要的粘结剂（水泥），作为水泥的部分替代品的补充材料（粉煤灰，空气石灰）和外加剂（引气剂，保水剂）制成的）。在本文中，对所选砂浆具有可接受的可加工性的砂浆进行了新鲜密度测试，流量，空气含量和保水性。最后，评估了新鲜特性和硬化特性之间的关系（从先前的研究中获得），以强调新鲜特性的重要性。总之，砂浆的新鲜行为主要受不同轻质骨料和掺合料掺入的影响。另外，从两个方面，即整体性能（新鲜性能，抗压强度，毛细管吸水率，热导率）和单个热性能进行了优化，以选择最合适的外墙涂料导热砂浆。总之，砂浆的新鲜行为主要受不同轻质骨料和掺合料掺入的影响。另外，从两个方面，即整体性能（新鲜性能，抗压强度，毛细管吸水率，热导率）和单个热性能进行了优化，以选择最适合外墙涂料的导热砂浆。总之，砂浆的新鲜行为主要受不同轻质骨料和掺合料掺入的影响。另外，从两个方面，即整体性能（新鲜性能，抗压强度，毛细管吸水率，热导率）和单个热性能进行了优化，以选择最合适的外墙涂料导热砂浆。