Incorporating façade-specific climatic factors to improve the ISO 15927-3 characterisation of wind-driven rain spells: Dutch and Spanish case studies

ISO standard 15927-3 characterise episodic exposures of wind-driven rain (WDR) on building façades by identifying wetting intervals, referred to as spells. Spells separated by 96 h or more without WDR are considered, assuming that this interval is sufficient for evaporative losses to exceed prior rainwater gains. This approach ignores variations in evaporation due to the façade orientation and local environmental factors, which cause diverse drying intervals even for the same material. This study proposes an estimation of potential evaporation losses in façades, considering their orientation and local climate. Representative drying intervals and enhanced façade-specific WDR spells are identified by combining potential evaporation losses with the directional WDR exposure. The results at locations in The Netherlands and Spain demonstrates that the drying intervals can vary significantly depending on these factors (regardless of the surface materials), which suggests reconsidering the current 96-h ISO model to minimise uncertainties when characterising episodic WDR exposures

Reciclado de escorias de fondo de central térmica para su uso como áridos en la elaboración de componentes prefabricados de hormigón

The need to eliminate waste generates costs. When considering the preservation of the environment, the minimization of the consumption of natural resources and energy savings criteria, the need and advisability of studying the feasibility of waste re-use seems clear. However, waste re-use depends on whether they are economically competitive. Therefore, the aim of this study is to evaluate the possible use of slag from a steam power station as aggregate in the manufacture of concrete. This study included the determination of the physical, chemical and thermal properties of the material, comparing the results to those required by the Spanish structural concrete code (EHE) in determining their acceptance or rejection as a concrete component. The ultimate aim of the research was to determine the highest slag content that could be added to concrete without modifying its strength or durability, with a view to obtaining savings in the manufacture of precast structures.La necesidad de eliminar residuos genera gastos. Considerando criterios de conservación ambiental, minimización del consumo de recursos naturales y ahorro de energía parece claro la necesidad y conveniencia de estudiar la viabilidad del uso de residuos. Sin embargo la utilización de residuos depende de que sean competitivos económicamente. Por tanto el propósito de esta investigación es evaluar el posible uso de las escorias de fondo de una central térmica como áridos para la fabricación de hormigón. En este estudio se incluye la determinación de características físicas, químicas y térmicas y se han comparado los resultados a los requeridos por la EHE para determinar su aceptación o rechazo como componente de un hormigón. El objetivo final de la investigación responde a la utilización de hormigón con el máximo contenido en escorias sin modificar las condiciones de resistencia y durabilidad, consiguiendo un ahorro económico en la fabricación de estructuras prefabricadas

Incorporating façade-specific climatic factors to improve the ISO 15927-3 characterisation of wind-driven rain spells: Dutch and Spanish case studies

ISO standard 15927-3 characterise episodic exposures of wind-driven rain (WDR) on building façades by identifying wetting intervals, referred to as spells. Spells separated by 96 h or more without WDR are considered, assuming that this interval is sufficient for evaporative losses to exceed prior rainwater gains. This approach ignores variations in evaporation due to the façade orientation and local environmental factors, which cause diverse drying intervals even for the same material. This study proposes an estimation of potential evaporation losses in façades, considering their orientation and local climate. Representative drying intervals and enhanced façade-specific WDR spells are identified by combining potential evaporation losses with the directional WDR exposure. The results at locations in The Netherlands and Spain demonstrates that the drying intervals can vary significantly depending on these factors (regardless of the surface materials), which suggests reconsidering the current 96-h ISO model to minimise uncertainties when characterising episodic WDR exposures

Closing the gap between traditional wind-driven rain studies and the performance-based design of building façades: Case study of the Netherlands

Over the last few decades, analyses of wind-driven rain exposure on building façades have been conducted in multiple regions. Sometimes, these studies also included the driving rain wind pressure, thereby characterising both critical factors contributing to rainwater penetration into façade materials. However, practitioners typically rely on performance results obtained from standardised watertightness tests to make façade design decisions, even though these tests do not recreate the specific exposure combinations that can occur on each façade. Consequently, there is no quantitative correlation between the traditionally identified exposures and actual façade designs, resulting in pure qualitative choices and poorly optimised designs. This study addresses this issue by correcting the existing methodological deficiencies in a prior calculation procedure, which aims to relate the exposure parameters that the façade configuration withstood during any watertightness test to the expected climate exposures at its design operating conditions. New contributions are presented to enhance the method reliability as well as to reduce calculation effort and reliance on exhaustive weather data. The various climate parameters required to establish this relationship were analysed and tabulated for the Netherlands, enabling a truly performance-based design of façades to resist rainwater penetration throughout the country. Different methods of implementing this procedure, according to the availability of weather data, were also compared for façade case studies located in Amsterdam and Maastricht