Grand Agreement no.: 608950

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Publishable summary

1 SUMMARY DESCRIPTION AND OBJECTIVES

Limited recourses and increasing population demands new ideas in sustainable development and growth. In particular in the energy sector and to be more specific, in energy conservation, there are still multiple options for technological advancement. In the building sector the advance of new technologies and materials help to show new perspectives to decentralize energy production, increase energy savings by smart facility installation and appliances as well as by increasing energy efficiency by new materials used for the building envelope. The latter is the focus of the SESBE project: Smart Elements for Sustainable Building Envelopes. SESBE develops new types of façade elements with integrated insulation for new buildings and the existing building stock. The main objectives are sustainability, safety and energy efficiency increase in conjunction with weight and thickness reduction of elements (Fig. 1).

A new type of concrete, Reactive Powder Concrete (RPC), allows reducing drastically the thickness of elements due to its high mechanical performance. Energy efficiency will be reached by a new type of insulation based on foam concrete with Quartzene® incorporation, an aerogel-like material. Functionalization of the materials by nanotechnology allows enlarging the performance of the elements with further properties, such as self cleaning/easy-to-clean, heat reflectance, and humidity buffering. Furthermore, a new type of sealing tape for element joints and openings is being developed as well as a more effective intumescent coating for anchors and the metal substructure.

The project itself consists of 6 work packages (WP). WP2 to WP5 are of technical and scientific content. WP2 is dedicated to material development, WP3 to material functionalization and WPs 4 and 5 in façade element design, performance and production technologies.

Fig. 1: Components of the new thin façade elements with RPC and foam concrete as insulation.

Grand Agreement no.: 608950

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2 WORK CARRIED OUT AND RESULTS SINCE BEGIN OF THE PROJECT

In the first 18 month (1st reporting period) the work was focused within WP2 and WP3 on material development and material functionalization. Besides this, management tasks were implemented, a project webpage was launched, poster/flyers designed and a first dissemination and exploitation plan written (in WPs 1 and 6).

The material development within WP2 focused on the fiber reinforced reactive powder concrete, on the insulation in form of foam concrete, the new sealing tape and the intumescent coating. RPC formulations were successfully developed by two of the partners, CBI and Acciona. The focus on the development was besides the performance the sustainability aspect by using industrial by-products. Figure 2 shows the compressive strength of formulations, which exceeds easily 140 MPa, Figure 3 the amount of industrial by-products used for the CBI’s RPC formulations.

The foam concrete development focused mainly on density reductions, which was reduced to 150 to 200 kg/m3 (Fig. 4). Thermal conductivities at this density range are in the range of 40 to 45 mW/(k.m). Quartzene® incorporation is now optimized and further reductions in thermal conductivities are expected. The design of a new sealing tape is ongoing. However, results are not completely satisfying and development needs still to be optimized.

The functionalization of surfaces is ongoing. First results show improved hydrophobic properties by combined application of textile imprints and bulk hydrophobic agent into the RPC (Fig. 5). In another development photocatalytic compounds were designed to have at the same time strong oleophobic properties. Improved heat reflectance was achieved on RPC surfaces by applying modified paint components as a coating.

Fig. 2: Strength development of two RPC formulations developed at CBI.

Grand Agreement no.: 608950

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Fig. 3: Amount of industrial waste materials in the 2 formulations developed by CBI.

Fig. 4: A cube of foam concrete, floating on water. The density of this specimen is around 350 kg/m3. The densities now reached by the consortium are in the range of 150 to 200 kg/m3.

Fig. 5: A RPC surface, modified by textile imprint and a bulk hydrophobic agent, is rendered hydrophobic.

3 FINAL RESULTS AND THEIR POTENTIAL IMPACTS AND USE

It is expected that the newly developed materials will help to drastically reduce the weight of façade elements and their thickness, without impairing or even increasing thermal performance. The utilized aerogel-like material Quartzene® can be produced at a much lower price as standard aerogel which is synthesized from silanes by autoclaving or low pressure drying. This will help to reduce costs for an inorganic, energy efficient, non-flammable insulation material, which is based on foam concrete with Quartzene® as component. That means alternatives to polymer based insulation, such as EPS or polyurethane, can be a real alternative for the future and help to increase fire safety,

Grand Agreement no.: 608950

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sustainability, energy efficiency and application of building elements containing this material. Ultra high strength materials for inner and outer façade layers have a multitude of advantages. They can be manufactured in much thinner dimensions and show at the same time an extreme durability. Due to the high strength and dense surface, surface functionalization can be performed better and more durable. It is expected that the production of new façade elements will not be as cheap as existing concrete elements until logistic production and distribution chains have been built up but money can already be saved for transport, application and operation. Dismantling elements will have a low environmental impact due to the mineral based nature of the material components.