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The paper aims to present a new insulating material based on cork aggregates and cement designed for building applications. Samples are prepared by mixing natural cork aggregates, sand, cement and water. Four cork volume dosages are considered, 0, 25, 50 and 75% (relative to the sand). Samples are characterised in terms of hardened density, compressive and flexural strength, as well as thermal conductivity and hydric properties (moisture content, vapour permeability, moisture buffering value and absorption by partial immersion). Results show that increasing cork granule amount tends to increase moisture retention and buffering value but decreases density, thermal conductivity and mechanical properties. Depending on the cork content, cork concrete mixture can be used as thermal insulator or as a structural component. [ABSTRACT FROM AUTHOR]

This article deals with the influence of both morphology and amount of Typha on hygrothermal behavior of a Typha–clay composite for building application. An agromaterial containing the fiber mix of Typha Australis and clay was made in three samples: three fiber mixtures were prepared with different amounts Typha and cut type (transversal or longitudinal). The physical properties of these materials were studied in terms of porosity, apparent and absolute density, thermal conductivity, and hygric properties. Results show a real impact of the Typha fraction type and its volume content on hygrothermal properties of the studied material due to the porosity. The transversal fraction of Typha (80% in volume weight) seems to be the optimal composition for a better hygrothermal behavior. [ABSTRACT FROM AUTHOR]

[Display omitted] • This study presents a state-of-the-art on thermal bridges focusing on slab on grade TB, including calculation methods, norms and software summary. • A numerical study of possible technical solutions to decrease slab on grade TB's effect is presented. • Different external insulation solutions to renovate existing building were compared. • The study highlights the effect of soil thermal properties on slab on grade TB calculation. • Improving insulation thickness and depth does not necessarily reduce the thermal bridges effect. The building industry is responsible for considerable energy consumption and the production of large amounts of greenhouse gas emissions worldwide. Hence, reducing the building heat losses that occur through the building envelope, especially through the floor foundations, is important. This paper provides an up-to-date review on thermal bridges (TBs), mainly with respect to slab-on-grade TBs. First, different thermal bridges types are defined; then the standards used to evaluate TBs are presented. Common approaches to evaluate TBs are discussed, such as the U-value method, the equivalent method approach, and the three-dimensional dynamic method. This latter focuses on heat loss through the foundation and soil in existing buildings. Soil's effect on thermal bridges is described and our case studies showed that thermal bridges heat losses are inversely proportional to soil thermal conductivity. This analysis is involved in the present paper. Finally, exterior insulation solutions at ground level are presented among those the trapezoidal double insulation type can reduce TBs up to 65% compared to no insulation case. As conclusions, directions for further works are suggested to fill current literature gaps. [ABSTRACT FROM AUTHOR]

Hemp shives is a lightweight material known for its insulating properties. Associating these bio-fibers with plant-based matrix instead of a mineral binder in insulation applications is of ecological interest. This article describes the study of a low environmental impact 100% plant-based material made solely from wheat starch and hemp shives. The hemp/starch ratio (H/S) influence and hemp shive size are studied. Samples are evaluated in terms of physical properties, mechanical behaviour and hygrothermal properties through an experimental approach. Results show that increasing 0–5 mm hemp shive proportion from 15% to 30% leads to a significant enhancement of the mechanical and hygric characteristics due to the load transfer and porosity. However, when the H/S ratio increases, mechanical and hygrothermal characteristics decrease slightly. Finally, the hemp-starch agro-material with H/S equal to 8 and 30% of 0–5 mm hemp shive seems to be the optimal composition between the studied samples. [ABSTRACT FROM AUTHOR]