Final Report Summary - EASIE (Ensuring Advancement in Sandwich Construction through Innovation and Exploitation)
Executive Summary:
The Ensuring Advancement in Sandwich Construction through Innovation and Exploitation (EASIE) was a European collaborative project targeted at SMEs funded by the European Commission under the FP7 Collaborative Work Program. The Project started on 1 October 2008 and was due for completion on 30 September2011 (36 months duration). The work extended until 31st December 2011. The project was composed of seven work packages, the first four of which have created new knowledge and design tools in areas where there had been previously little or no research. The fifth and sixth work packages disseminated and exploited both new and existing information in practice. The seventh work package dealt with management and governance.
Improvement of thermal and structural behavior in openings and joints (WP1)
Thermal loss in joints and openings were investigated. Very good water tightness could be stated for all tested systems with and without windows. In all tests the highest class of tightness according to EN 14509 was reached. All key test results and instructions for the industry regarding the fabrication and the mounting are given in a “Design guidelines for good panel joints and joints sealing openings focusing on air and water tightness”. New calculation models for roof panels with small openings were developed, based on experimental and numerical investigations. Tests on wall panels with small openings and window frames showed that frames improve the load bearing capacity of panels with openings clearly. For large openings with reinforcement three different calculation models were developed depending on the kind of reinforcement
End user focused design strategies (WP2)
The aim of the work was to develop a design by testing method for the sandwich panels in view to complete the design by calculation already in the European standard, the EN 14509.
Two methods were developed, one to calibrate the theoretical results with the real behaviour of the panels below a thermal gradient alone (factor βΔT between 0.92 and 1.03) and one to carry out and analyse large scale tests were simultaneously are applied a thermal gradient and a mechanical loading.
Two theoretical guidelines with numerical examples were developed, one for the cladding panels with two flat facings and one for the roofing panel with one face ribbed and one face flat. A parametric study based on the numerical examples mentioned above comparing the load span tables obtained with the design by testing method and obtained with the design by calculation method was done.
Excel sheets based on 3 modules (one for the design of the bending and shear rigidities, one for the design of the strength capacities, and one for the determination of the load/span tables) were produced. A draft annex design by testing has been prepared for CEN for future incorporation into EN14509.
Use of sandwich technology to optimize the global resistance of buildings (WP3)
The overall aim of this work was to provide design models and calculation procedures, which enable to utilize the high resistance of sandwich panels to in-plane shear and axial forces.
Experimental and numerical investigations were carried out to evaluate how sandwich panels increase the resistance of beams and purlins against lateral torsional buckling by restraining rotations and lateral displacements. A design model was developed. Calculation procedures for determining the forces of fastenings, which are decisive for the load bearing behaviour, and capacity of shear loaded sandwich panels, were developed. Design expressions for fastenings of sandwich panels to a steel substructure were developed. The buckling of axially loaded sandwich panels was studied experimentally and numerically and a design concept was formulated. A design model based on the wrinkling stress determined by tests according to EN 14509 was developed. Based on the different investigations on frameless structures (transfer of horizontal loads, forces of the fastenings) a Design and Construction Guideline for buildings without substructure was prepared and published. The measurement of time-dependent effects was carried out on large demonstrator.
Retrofitting, durability and maintenance of sandwich panels (WP4)
Data from previous R&D and practical applications were assembled in a structured database. A substantial number of small and large scale tests were carried out on aged sandwich panels with test coupons being subjected to an accelerated ageing process. These were complemented by tests on old panels which had been taken out of service. Improvements were proposed to existing design methods and models to take into account the effect of ageing on the behaviour and failure modes of sandwich panels. The influence of ageing on the behaviour and failure mode and loads of sandwich panels was modelled. A method was developed to evaluate the remaining service life of sandwich panels taking into account ageing and blistering damage. The main retrofitting methods were investigated and a new innovative simplified methods adapted to SMEs capabilities was developed.
Holistic, e-learning based education on sandwich construction (WP5)
This work has produced a portfolio of publicly available web-based resources for the improvement of knowledge of sandwich panels including a series of eLearning modules, a list of relevant literature, of guidelines and examples of good practice and of relevant standards and regulations.
Training, skill development and dissemination (WP6)
The objectives of this work were to pass on the knowledge and academic information to the market for its improvement and development, to promote wide adoption of the project’s output by industry and in particular by SMEs, by regulators and by standards organisations and to develop a post-project strategy to ensure project legacy, ownership of the process and continuous implementation and use of the project’s results. Ten e-newsletters were published in English and Spanish during the project. They were circulated to an extensive list of industrial contacts and made available online. Three user-focused industry workshops on the theme “Building with sandwich panels fast, safe and energy saving” have were held in Zagreb, Croatia on 17th June 2010, in Barcelona, Spain on 24th March 2011, and in Krakow, Poland on 9th June 2011, with special regards to the needs of local industries. They were recorded on video “and uploaded on the EASIE website. The website, www.easie.eu was regularly updated and the number of hits went up steadily over the life of the project. The EASIE Final conference (Rome on 22 and 23 September 2011) with over 120 participants from 20 different countries (in majority from the European Union) provided the best showcase possible for the dissemination of the research to as wide a spectrum of companies as possible. A User Guide targeted at industrial users has been produced together with a database of industrial contacts across Europe relevant to the sandwich panel industry. A post-project strategy was agreed by the Participants in order to manage the Project’s legacy.
Project Context and Objectives:
Overall Context
Sandwich panels are modern lightweight building components used to cover walls and roofs of buildings and to isolate spaces inside buildings. They are typically made of two thin metal (mainly steel) sheets with an insulating core (mainly polyurethane or mineral wool) between the faces. Sandwich panels are industrially made products, which provide high load-bearing capacity, superior thermal insulating properties and air tightness with a low self-weight. The use of sandwich panels has been increasing worldwide and new application areas are continuously opened in industrial, residential and commercial buildings.
The total annual production of light-weight sandwich panels in Europe is about 100 million m2 per year, the value of which exceeds roughly to 2.5 billion € per year. The corresponding numbers in the whole globe are about 200 million m2 and 4.5 billion € per year. Figures in Europe have been rather stable in the last few years, but Southeast Asian and South American markets are rapidly growing. The numbers show the importance of the industrial production of sandwich panels in Europe and throughout the world.
The design and use of sandwich panels is based in most countries in Europe on European Recommendations for Sandwich Panels (European Recommendations for Sandwich Panels, Part I: Design. Published by CIB in 2000 and ECCS in 2001) published by ECCS and CIB organisations. In some countries such as France or Spain, national standards differing from these Recommendations are in use. A new European product standard for sandwich panels was been prepared by the CEN/TC128/SC11 (EN 14509:2005(E), Self-supporting double skin metal faced insulating panels – Factory made products – Specifications) at project inception. This is a standard which focuses on the basic sandwich panel product and therefore does not cover the issues relating to panel systems, to installation and to decommissioning. The results of the project will be implemented in the next draft of the European standard EN 14509 for sandwich panels.
Some research work has been carried out in Europe during the recent past. But a number of important questions in light-weight steel construction with sandwich panels remain unanswered. This includes in particular the use of sandwich panels as stabilization and axially loaded bearing elements, the impact of openings on the structural behaviour of the panels and the very important issue of durability of the overall system. Solving these issues will result in more sustainable and energy efficient buildings.
Until now, the industry, which is dominated by small to medium size enterprises (SMEs), has not been able to carry out the detailed scientific evaluation, modelling and large scale testing necessary to address the increasing demand for innovative, economic and safe high technology sandwich products. This has resulted in a growing gap in knowledge which is starting to affect the construction industry’s capacity to compete and innovate.
Therefore, there is a real need for a European research project to close this gap in knowledge and to prepare European guidelines and directions for the use in practice, and to disseminate the results widely across the industry. With these results the European sandwich industry will be enabled to better withstand the pressure of global competition and to enlarge its share on the construction market both in Europe and beyond.
Aims and objectives
The overall goal of EASIE is for SMEs to make the use of a range of high-technology construction products focusing on sandwich panel technology more effectively and more innovatively to improve the quality and energy-efficiency in building and to allow easier retrofitting and maintenance and to improve the competitiveness of a key EU industrial sector which is dominated by SMEs.
The detailed strategic (SGs) and operational (OGs) goals of EASIE are:
SG1 Identify, analyse and solve gaps, deficiencies and shortcomings in current sandwich panel construction focusing in particular on joints and openings. This strategic goal is supported by a series of operational goals including:
- OG1.1 Investigate thermal loss in joints and openings and evaluate remedial solutions
- OG1.2 Investigate the mechanical strength of sandwich panels with small and large openings and develop predictive analytical methods
- OG1.3 Produce design guidelines for improved joints and openings in panels
SG2 Assemble, analyse and test key improvements for a test based design method for sandwich panel systems with a defined safety concept and which can form the basis of a guideline and proposal for the next draft of EN 14509. This strategic goal is supported by a series of operational goals including:
- OG2.1 Identify and evaluate methods currently in use for simulating temperature loads
- OG2.2 Conduct parametric study comparing the design by testing and the design by calculation methods based on existing panel systems
- OG2.3 Compile a design by testing guideline for input to EN 14509 and for practical direct application by SMEs.
- OG2.4 Produce a validate a software tool based on Excel allowing a simplified method to evaluate results from test based design method
SG3 Use of the high resistance of sandwich panels to in-plane shear and axial forces to improve the structural behaviour of steel construction elements (purlins, wall frames) This strategic goal is supported by a series of operational goals including:
- OG3.1 Carry a detailed survey of construction elements to be tested
- OG3.2 Perform series of tests with various core/face combinations under axial loads
- OG3.3 Incorporate experimental result into design manual
- OG3.4 Apply/validate all results to one practical application (Final selection will be made by the Industrial Committee but application is likely to be for the design of a cold/chill room)
SG4 Assess the retrofitting, durability and maintenance of sandwich panel systems and propose design solutions to improve their long term structural performance. This strategic goal is supported by a series of operational goals including:
- OG4.1 Assemble all available data (from previous R&D and practical applications) in a structured database
- OG4.2 Conduct a substantial small and large scale experimental programme in three laboratories on aged sandwich panels
- OG4.3 Propose improvements to existing design methods and models to take into account the effect of ageing on the behaviour and failure modes of sandwich panels
- OG4.4 Review and evaluate/test main retrofitting methods and propose new innovative simplified methods adapted to SMEs capabilities.
SG5 Improve the diffusion of information and knowledge on sandwich construction technology amongst students and practitioners in industry. This strategic goal is supported by a series of operational goals including:
- OG5.1 Develop a portfolio of internet-based lectures within a comprehensive e-learning framework. The lectures will be tailored to address the interests of two main audiences: students and SMEs staff/practical engineers
- OG5.2 Compilation of an online freely-available library/database on sandwich technology. This library will be maintained by ISM and TUD beyond the end of the project.
SG6 Promote the wide adoption of the project results by the industry through training, skill development and dissemination actions. This strategic goal is supported by a series of operational goals including:
- OG6.1 Production of quarterly internet-based newsletter
- OG6.2 Organise with support from all major Industrial associations and groupings active in the field two EU training workshops and one major ICPC conference
- OG6.3 Organise a final EASIE European conference
- OG6.4 Develop a post-project strategy to ensure continuous dissemination and use of project results
Major scientific advances are expected from the project in four main areas:
Design: the current design procedures are limited in their scope and applicability. It is restricted to continuous multi span panel elements acting independently of the substructure. The design concept includes elastic compound of the sandwich cross section material components and the influence of load actions such as temperature differences between the face, long term shear strength and creep effects.
The project innovative steps will include the development of design concepts for the contribution of the cladding elements to the global stabilization of the building (e.g. stabilization of purlins and racking resistance of the whole building structure), the incorporation of openings (doors, windows, ducts, etc.) into the design and the behaviour of axially loaded elements when used without a supporting structure (e.g. cold or chill rooms).
Energy balance: an increasing use of sandwich panels will enable the construction industry to adapt to climate change by reducing the CO2 emissions through better insulation and tightness of buildings, through refurbishment of energy intensive old buildings and through reducing the consumption of energy during the production process by reducing weight of the cladding structure. Optimization of energy consumption both, during production of the element and lifetime through minimization of defective goods and improvement of tightness of the building envelope.
Training: the perennial problem faced by the composite industry in general and by the sandwich panel industry in particular is the near absence of long term and professional training of the workforce, both for students in the university, as it is not part of the taught curriculum in most European universities and for workers. The project will address both these shortcomings by developing a series of targeted lectures in electronic form for civil engineering and architecture students and by developing tailor made professional continuous training packages available both, online and in CD format. The EASIE project will also produce a virtual library available online to the public.
Sustainability: the adaptation of the existing building stock in Europe to climate change is a key problem particular in the new Member States. Sandwich elements are a consistent, quality controlled, industrially mass produced product. The EASIE project will enable a better understanding of their behaviour in service and through life. It will develop and propose procedures to allow easier incorporation/retrofitting of sandwich panels in the fabric of existing buildings and replacement or easier repair of defective elements. It will result in a product which is consistent, better understood with a reduction in raw material consumption by extensive exploitation of the potentials of all building components.
Durability: the project will enable an accurate prediction of the product lifecycle by determining “fit for purpose” state at any given time allowing the determination of remaining service time for existing constructions.
In addition to these scientific technical advances, the project will make substantial headways in changing existing mind-sets which prevent the wider adoption of sandwich panel technology across the industry. Despite decades of use in the field, sandwich panels are still considered a new, relatively untried technology. This is mainly due to the fact that sandwich technology is not part of the curriculum of most engineering courses and suitable training materials are not available for in service training of the existing workforce.
Project Results:
More detailed information can be found in the attached pdf-file!
WP1 focused on two areas, air permeability of panel joints (causing thermal losses) and structural effects of openings on panel assembly, which are of fundamental importance for the successful application and use of sandwich panels.
The work developed guidelines on good practice for panel joints with regard to water and air permeability and models for the assessment of strength of panels with openings as well as distribution of loads between panels with openings in a wall panel assembly.
WP2 was concerned with the development of the design by testing method and its applicability in parallel with the design by calculation method. The development of the thermal test method was completed and was validated through an extensive experimental programme and parametric study.
WP3 produced a substantial experimental database and an evaluation and analysis of the results for in-plane shear resistance to stabilize buildings, both in a conventional design with a steel framework and in a frameless building. A design model for panels under axial loads based on known values was developed. Guideline for good practice regarding sandwich constructions without substructure has been completed, consisting of 3 parts: Part 1: Design guideline, Part 2: Construction guideline and Part 3: Draft of amendment for EN 14509.
WP4 described the influence of ageing on the shear strength and on the wrinkling strength based on the information available from manufacturers and users of sandwich panels and on an in-depth analysis of the different faults and defects and the possible repair methods. The results of the artificial ageing tests and of the tests on old panels were analysed. Existing models on the development of the cross-panel tensile strength of the sandwich panels when exposed to natural environmental effects were reviewed and evaluated. Improvement of Design Expressions was first written in draft form on the basis of the first batch of experimental results before being finalised in November 2011. A model to evaluate remaining service life was produced. A new method for the in-situ repair of sandwich panels with blisters or local damage was developed and trialled.
WP5 focused on the production of eLearning resources for the improvement of the knowledge of the use of sandwich panels in buildings. An extensive list of electures were recorded and made available on the project’s website at www.easie.eu. A list of relevant literature and codes on sandwich panels for the major EU countries was collected. Guidelines of good practice were assembled on the basis of the information received from the industrial Participants.
WP6 focused on dissemination and use of the results. Ten e-newsletters were published on the project’s website. A User Guide based on the key results from the project was published in paper form and on the project’s website. Three user-focused industry workshops on the theme “Building with sandwich panels’ fast, safe and energy saving” were held in Zagreb, Croatia on 17th June 2010, in Barcelona, Spain on 24th March 2011, and in Krakow, Poland on 9th June 2011, with special regards to the needs of local industries. A post-project strategy was agreed by the Participants in order to manage the project’s legacy.
The project has contributed to standards in a number of ways in particular, through personal contacts and overlapping membership, by regular feedbacks to the European Committee for Standardisation (CEN) TC 128/SC11 and especially WG1, WG2 and WG5 who were dealing with the European standard EN14509 and to the European Joint Committee on Sandwich Constructions formed of ECCS TWG 7.9 Technical Working Group and CIB W 56 Working Commission. Major part of the EASIE work, in particular WP1 and WP2, are being incorporated into existing standards and guidelines.
Potential Impact:
The proposal has met most of the expected impacts specified in the call and listed in the work programme. The project addressed the objectives of the Framework Topic NMP-2007-4.0-6 Innovative added-value construction product-services. More specifically it has achieved major technical, economic, industrial, environmental and social improvements and advances which will diffuse across the European Union in the coming years. These have included in particular:
- The development and improvement of a highly knowledge-based construction processes and products, sandwich technology, which is mainly deployed by SMEs and especially used for the retrofit, refurbishment and maintenance of buildings, but also the opening of new market segments for sandwich technology by establishing formal fundamentals and broadening awareness through education and learning.
- The modernisation of a number of SMEs businesses by developing new construction knowledge-based services and products, improving their competitiveness with crucial impact on employment and growth and making available new technologies and industrial practices.
- The reduction of the impact of a number of construction technologies on the environment based on the optimum sustainable use of new construction materials in the form of sandwich panels, improving their production, installation, durability, reuse and retrofitting.
- A major contribution to technology innovation in the EU by addressing the urgent issue of rehabilitation and regeneration of many urban areas of Europe particularly in many new member countries, to help adapt buildings and infrastructures across the European Union to cope with expected change to climate change and withstand adverse weather conditions and to enable the construction industry to contribute towards the increasingly demanding targets in reduction of CO2 emissions.
- A contribution to knowledge-based upgrading by delivering an optimised product suitable for retrofitting of the existing building stock and also suitable for use in new built.
The results of the EASIE research have closed existing scientific gaps that have hitherto hindered sandwich panel construction from gaining a larger market share. This includes obvious shortcomings such as lacking knowledge about the effects of openings in sandwich panels, about the contribution of the sandwich building envelop to the global load bearing capacity of a structure and about the ability of sandwich structures to take axial loads. The industry has acknowledged the substantial impact that the project’s research has had on the sector.
The development of a European wide accepted test based design method has given producers across EU countries the freedom of acting according to their habitual design method ensuring comparability and will give the potential to solve specific application situations through sound engineering. The method will help to exploit the structural potential of sandwich panel further.
Deriving a sound design procedure including the log term structural performance of a sandwich element will strength the costumer confidence and give producers and engineers the possibility to design their product according to their needs.
The European construction sector is a major contributor to exports. This is particularly true for high added value products that require excellent engineering such as composite sandwich elements. The building material sector is recognizing a growing potential in emerging markets in developing countries and is diversifying. Many of these markets employ sandwich construction for structural and economic reasons. The high potential in energy saving that sandwich elements offer is not often perceived as a sales argument but becomes increasingly important during the lifetime and resale.
The market for exchange of the panels in the EU is large so the potential on the market should be high. However sandwich elements today only take a share of 10 to 15 % of the thin wall steel profile market. The results of the EASIE research and particularly its dissemination will help the sandwich panel sector to increase this share by eliminating formal, technological and sociocultural aspects hindering the sector to expand further. A further market penetration in the thin wall steel sector of only 10 % will lead to a doubling in turnover for the sector and will move the construction industry further towards a technology driven, progressive and modern industry sector.
There is a potential to achieve more advanced knowledge-based upgrading of existing buildings as the project has provided a substantial library of validated data regarding long term behaviour of sandwich panels and the development of additional elements for improving bearing structures applicable in refurbishment and retrofitting of old buildings. Validated methods of repair and maintenance will help to maintain and improve the existing, highly valuable building stock across the European Union.
Changes in construction practices are necessary to help adapt buildings and infrastructures across the European Union to expected changes in climate change and in particular to adapt to an increase in extreme weather events. The construction industry will also have to contribute towards the increasingly demanding national and international targets in reduction of CO2 emissions.
Half of all CO2 emissions are building-related and nearly a third of these come from housing. Over 10% of global CO2 emissions are related to the manufacture and transport of construction materials and the construction process. It is widely acknowledged that the greatest potential to reduce emissions in the construction industry sector is associated with the existing, occupied building stock.
By promoting an increasing use of sandwich panels for both the refurbishment of existing buildings and for new built, the project’s has contributed to a global reduction in the energy consumption of the building stock through improved thermal insulation and better controlled indoor environments.
The project has also contributed to an improvement in working quality and conditions. Training within EASIE has focused on activities which were essential to achieving the objectives of the project, which contributed to the professional development of the engineers and scientists involved and which contributed to the formation of a skilled workforce capable of answering the challenges presented by new technologies, new industrial processes and evolving national and European regulations, codes and standards.
The project has developed methods, based on sandwich panels, to better utilize existing buildings and to create new solutions and practices to use sandwich panels in innovative way in new constructions. This has, and will in future, lead to an expansion of the market of the sandwich panel industry and thus, will offer more work places in future in EU. The increased use of highly engineered construction systems will help in the trend of shifting the construction workforce from unskilled workers to a highly skilled workforce.
New methods to evaluate the service life of sandwich panels make possible to define more clearly the technical and economic value of the existing and new panels. The project will develop solutions to retrofit existing building stock based on sandwich panels in order to achieve the requirements for safety, thermal insulation and air and water tightness. It also may show solutions to reuse the panels in new applications.
The project was pre-normative in character but has contributed significantly to the standardisation activity in Europe. Standardization provides a harmonised basis for the manufacturing, design and use and thus, improves the climate of the competition market. It alsoimproves the quality of the product by defining exactly expressed requirements and by giving high-quality method for the verification of the required properties. The developments in European standardisation have also a direct effect on other export markets as often European standards are either amended as national standards or, where national standards are extremely weak or even lacking, producing in accordance with the European standard on sandwich elements gives major competitive advantages.
The project has also contributed to standards in several other ways, including feedback through analysis of best practice. The feedback has occurred through different standardisation committees including in particular the European Committee for Standardization (CEN) TC 128/SC 11 which is dealing with the European harmonized standard on sandwich panels. The developments of technical rules which have and will support pre-standard works are one of the project’s lasting legacy
Sandwich panels are manufactured by many companies in many countries throughout the world to a variety of national or regional manufacturer standards. However the normative and regulatory regimes under which they are designed and installed are fairly weak. The sharing of knowledge amongst panel manufacturers, designers, and installers which has been promoted by the Industrial associations which have participated in the project will improve the finished product and is an essential condition to increasing the competitiveness of EU companies and to extending their business beyond Europe.
The European community also carries with it the idea of European level solutions, and an important benefit of working collectively across national borders on problems, which have large-scale strategic importance, is that the solutions ultimately satisfy the European dimension rather than the purely national one. This also serves to influence, and helps to integrate national policies into a European framework by developing the core technologies under a community programme from which all members can draw. The numerous dissemination activities (user-focused workshops, user guide, enewsletters, industrial conferences) undertaken by the project have helped in this process.
To survive, grow and prosper SMEs must constantly innovate, developing new technologies themselves or obtaining new technologies through technology transfer. The central aim of the project was to expand their knowledge base and enhance the overall competitiveness of a large community of SMEs which have the capacity to innovate but with limited R&D facilities. The project has harnessed the skills and expertise of five major European Industrial Associations and Groupings (APIPNA, EPAQ, Pan and Pro Europe, SNPPA) which have a membership made up almost exclusively of SMEs and from the European Convention for Constructional Steelwork (ECCS) and has enroled the support of the International Council for Research and Innovation in Building and Construction (CIB) who are also focusing a major part of their activities on the needs of SMEs.
The Project has provided a comprehensive package of innovative technological products and training tools tailor made to the needs of SMEs. This has helped SMEs and their industrial associations:
- To acquire an enhanced capability to economically design and manufacture fit for purpose sandwich panels in new buildings but also in existing buildings.
- To deliver to clients a more competitive product able to accommodate the requirements defined by the clients of the construction industry as well as the requirements defined by harmonized EU standards.
- To broaden the scope and enhance the quality of European standards allowing better exploitation of the products properties giving further advantages over competing, labour-intensive and error-prone construction methods.
- To receive help and guidance in accessing and incorporating in design and production fast changing engineering practices and regulations, codes and standards
- To obtain scientifically based solutions to a number of issues which were previously dealt with through intuitive engineering judgment thereby reducing the potential margin of error and risk of failure and accident
- To operate within an improved climate for fairer competition within the industry resulting from level playing field across Europe and through increased certainty as to the “rules of the game” by ensuring the development of widely applicable standards
- To gain a better insight of, and influence on, national and European legislation with regard to product requirement and liability, environment, on-going development and research and end-use applications
- To benefit from training of staff, exchanges with a wide range of stakeholders across the European Union and privileged access to a range of data sets, models, design, guidance, best practice and generally user focused technical information
- To benefit from the internet-based E-Learning facility established by the project.
The Ensuring Advancement in Sandwich Construction through Innovation and Exploitation (EASIE) was a European collaborative project targeted at SMEs funded by the European Commission under the FP7 Collaborative Work Program. The Project started on 1 October 2008 and was due for completion on 30 September2011 (36 months duration). The work extended until 31st December 2011. The project was composed of seven work packages, the first four of which have created new knowledge and design tools in areas where there had been previously little or no research. The fifth and sixth work packages disseminated and exploited both new and existing information in practice. The seventh work package dealt with management and governance.
Improvement of thermal and structural behavior in openings and joints (WP1)
Thermal loss in joints and openings were investigated. Very good water tightness could be stated for all tested systems with and without windows. In all tests the highest class of tightness according to EN 14509 was reached. All key test results and instructions for the industry regarding the fabrication and the mounting are given in a “Design guidelines for good panel joints and joints sealing openings focusing on air and water tightness”. New calculation models for roof panels with small openings were developed, based on experimental and numerical investigations. Tests on wall panels with small openings and window frames showed that frames improve the load bearing capacity of panels with openings clearly. For large openings with reinforcement three different calculation models were developed depending on the kind of reinforcement
End user focused design strategies (WP2)
The aim of the work was to develop a design by testing method for the sandwich panels in view to complete the design by calculation already in the European standard, the EN 14509.
Two methods were developed, one to calibrate the theoretical results with the real behaviour of the panels below a thermal gradient alone (factor βΔT between 0.92 and 1.03) and one to carry out and analyse large scale tests were simultaneously are applied a thermal gradient and a mechanical loading.
Two theoretical guidelines with numerical examples were developed, one for the cladding panels with two flat facings and one for the roofing panel with one face ribbed and one face flat. A parametric study based on the numerical examples mentioned above comparing the load span tables obtained with the design by testing method and obtained with the design by calculation method was done.
Excel sheets based on 3 modules (one for the design of the bending and shear rigidities, one for the design of the strength capacities, and one for the determination of the load/span tables) were produced. A draft annex design by testing has been prepared for CEN for future incorporation into EN14509.
Use of sandwich technology to optimize the global resistance of buildings (WP3)
The overall aim of this work was to provide design models and calculation procedures, which enable to utilize the high resistance of sandwich panels to in-plane shear and axial forces.
Experimental and numerical investigations were carried out to evaluate how sandwich panels increase the resistance of beams and purlins against lateral torsional buckling by restraining rotations and lateral displacements. A design model was developed. Calculation procedures for determining the forces of fastenings, which are decisive for the load bearing behaviour, and capacity of shear loaded sandwich panels, were developed. Design expressions for fastenings of sandwich panels to a steel substructure were developed. The buckling of axially loaded sandwich panels was studied experimentally and numerically and a design concept was formulated. A design model based on the wrinkling stress determined by tests according to EN 14509 was developed. Based on the different investigations on frameless structures (transfer of horizontal loads, forces of the fastenings) a Design and Construction Guideline for buildings without substructure was prepared and published. The measurement of time-dependent effects was carried out on large demonstrator.
Retrofitting, durability and maintenance of sandwich panels (WP4)
Data from previous R&D and practical applications were assembled in a structured database. A substantial number of small and large scale tests were carried out on aged sandwich panels with test coupons being subjected to an accelerated ageing process. These were complemented by tests on old panels which had been taken out of service. Improvements were proposed to existing design methods and models to take into account the effect of ageing on the behaviour and failure modes of sandwich panels. The influence of ageing on the behaviour and failure mode and loads of sandwich panels was modelled. A method was developed to evaluate the remaining service life of sandwich panels taking into account ageing and blistering damage. The main retrofitting methods were investigated and a new innovative simplified methods adapted to SMEs capabilities was developed.
Holistic, e-learning based education on sandwich construction (WP5)
This work has produced a portfolio of publicly available web-based resources for the improvement of knowledge of sandwich panels including a series of eLearning modules, a list of relevant literature, of guidelines and examples of good practice and of relevant standards and regulations.
Training, skill development and dissemination (WP6)
The objectives of this work were to pass on the knowledge and academic information to the market for its improvement and development, to promote wide adoption of the project’s output by industry and in particular by SMEs, by regulators and by standards organisations and to develop a post-project strategy to ensure project legacy, ownership of the process and continuous implementation and use of the project’s results. Ten e-newsletters were published in English and Spanish during the project. They were circulated to an extensive list of industrial contacts and made available online. Three user-focused industry workshops on the theme “Building with sandwich panels fast, safe and energy saving” have were held in Zagreb, Croatia on 17th June 2010, in Barcelona, Spain on 24th March 2011, and in Krakow, Poland on 9th June 2011, with special regards to the needs of local industries. They were recorded on video “and uploaded on the EASIE website. The website, www.easie.eu was regularly updated and the number of hits went up steadily over the life of the project. The EASIE Final conference (Rome on 22 and 23 September 2011) with over 120 participants from 20 different countries (in majority from the European Union) provided the best showcase possible for the dissemination of the research to as wide a spectrum of companies as possible. A User Guide targeted at industrial users has been produced together with a database of industrial contacts across Europe relevant to the sandwich panel industry. A post-project strategy was agreed by the Participants in order to manage the Project’s legacy.
Project Context and Objectives:
Overall Context
Sandwich panels are modern lightweight building components used to cover walls and roofs of buildings and to isolate spaces inside buildings. They are typically made of two thin metal (mainly steel) sheets with an insulating core (mainly polyurethane or mineral wool) between the faces. Sandwich panels are industrially made products, which provide high load-bearing capacity, superior thermal insulating properties and air tightness with a low self-weight. The use of sandwich panels has been increasing worldwide and new application areas are continuously opened in industrial, residential and commercial buildings.
The total annual production of light-weight sandwich panels in Europe is about 100 million m2 per year, the value of which exceeds roughly to 2.5 billion € per year. The corresponding numbers in the whole globe are about 200 million m2 and 4.5 billion € per year. Figures in Europe have been rather stable in the last few years, but Southeast Asian and South American markets are rapidly growing. The numbers show the importance of the industrial production of sandwich panels in Europe and throughout the world.
The design and use of sandwich panels is based in most countries in Europe on European Recommendations for Sandwich Panels (European Recommendations for Sandwich Panels, Part I: Design. Published by CIB in 2000 and ECCS in 2001) published by ECCS and CIB organisations. In some countries such as France or Spain, national standards differing from these Recommendations are in use. A new European product standard for sandwich panels was been prepared by the CEN/TC128/SC11 (EN 14509:2005(E), Self-supporting double skin metal faced insulating panels – Factory made products – Specifications) at project inception. This is a standard which focuses on the basic sandwich panel product and therefore does not cover the issues relating to panel systems, to installation and to decommissioning. The results of the project will be implemented in the next draft of the European standard EN 14509 for sandwich panels.
Some research work has been carried out in Europe during the recent past. But a number of important questions in light-weight steel construction with sandwich panels remain unanswered. This includes in particular the use of sandwich panels as stabilization and axially loaded bearing elements, the impact of openings on the structural behaviour of the panels and the very important issue of durability of the overall system. Solving these issues will result in more sustainable and energy efficient buildings.
Until now, the industry, which is dominated by small to medium size enterprises (SMEs), has not been able to carry out the detailed scientific evaluation, modelling and large scale testing necessary to address the increasing demand for innovative, economic and safe high technology sandwich products. This has resulted in a growing gap in knowledge which is starting to affect the construction industry’s capacity to compete and innovate.
Therefore, there is a real need for a European research project to close this gap in knowledge and to prepare European guidelines and directions for the use in practice, and to disseminate the results widely across the industry. With these results the European sandwich industry will be enabled to better withstand the pressure of global competition and to enlarge its share on the construction market both in Europe and beyond.
Aims and objectives
The overall goal of EASIE is for SMEs to make the use of a range of high-technology construction products focusing on sandwich panel technology more effectively and more innovatively to improve the quality and energy-efficiency in building and to allow easier retrofitting and maintenance and to improve the competitiveness of a key EU industrial sector which is dominated by SMEs.
The detailed strategic (SGs) and operational (OGs) goals of EASIE are:
SG1 Identify, analyse and solve gaps, deficiencies and shortcomings in current sandwich panel construction focusing in particular on joints and openings. This strategic goal is supported by a series of operational goals including:
- OG1.1 Investigate thermal loss in joints and openings and evaluate remedial solutions
- OG1.2 Investigate the mechanical strength of sandwich panels with small and large openings and develop predictive analytical methods
- OG1.3 Produce design guidelines for improved joints and openings in panels
SG2 Assemble, analyse and test key improvements for a test based design method for sandwich panel systems with a defined safety concept and which can form the basis of a guideline and proposal for the next draft of EN 14509. This strategic goal is supported by a series of operational goals including:
- OG2.1 Identify and evaluate methods currently in use for simulating temperature loads
- OG2.2 Conduct parametric study comparing the design by testing and the design by calculation methods based on existing panel systems
- OG2.3 Compile a design by testing guideline for input to EN 14509 and for practical direct application by SMEs.
- OG2.4 Produce a validate a software tool based on Excel allowing a simplified method to evaluate results from test based design method
SG3 Use of the high resistance of sandwich panels to in-plane shear and axial forces to improve the structural behaviour of steel construction elements (purlins, wall frames) This strategic goal is supported by a series of operational goals including:
- OG3.1 Carry a detailed survey of construction elements to be tested
- OG3.2 Perform series of tests with various core/face combinations under axial loads
- OG3.3 Incorporate experimental result into design manual
- OG3.4 Apply/validate all results to one practical application (Final selection will be made by the Industrial Committee but application is likely to be for the design of a cold/chill room)
SG4 Assess the retrofitting, durability and maintenance of sandwich panel systems and propose design solutions to improve their long term structural performance. This strategic goal is supported by a series of operational goals including:
- OG4.1 Assemble all available data (from previous R&D and practical applications) in a structured database
- OG4.2 Conduct a substantial small and large scale experimental programme in three laboratories on aged sandwich panels
- OG4.3 Propose improvements to existing design methods and models to take into account the effect of ageing on the behaviour and failure modes of sandwich panels
- OG4.4 Review and evaluate/test main retrofitting methods and propose new innovative simplified methods adapted to SMEs capabilities.
SG5 Improve the diffusion of information and knowledge on sandwich construction technology amongst students and practitioners in industry. This strategic goal is supported by a series of operational goals including:
- OG5.1 Develop a portfolio of internet-based lectures within a comprehensive e-learning framework. The lectures will be tailored to address the interests of two main audiences: students and SMEs staff/practical engineers
- OG5.2 Compilation of an online freely-available library/database on sandwich technology. This library will be maintained by ISM and TUD beyond the end of the project.
SG6 Promote the wide adoption of the project results by the industry through training, skill development and dissemination actions. This strategic goal is supported by a series of operational goals including:
- OG6.1 Production of quarterly internet-based newsletter
- OG6.2 Organise with support from all major Industrial associations and groupings active in the field two EU training workshops and one major ICPC conference
- OG6.3 Organise a final EASIE European conference
- OG6.4 Develop a post-project strategy to ensure continuous dissemination and use of project results
Major scientific advances are expected from the project in four main areas:
Design: the current design procedures are limited in their scope and applicability. It is restricted to continuous multi span panel elements acting independently of the substructure. The design concept includes elastic compound of the sandwich cross section material components and the influence of load actions such as temperature differences between the face, long term shear strength and creep effects.
The project innovative steps will include the development of design concepts for the contribution of the cladding elements to the global stabilization of the building (e.g. stabilization of purlins and racking resistance of the whole building structure), the incorporation of openings (doors, windows, ducts, etc.) into the design and the behaviour of axially loaded elements when used without a supporting structure (e.g. cold or chill rooms).
Energy balance: an increasing use of sandwich panels will enable the construction industry to adapt to climate change by reducing the CO2 emissions through better insulation and tightness of buildings, through refurbishment of energy intensive old buildings and through reducing the consumption of energy during the production process by reducing weight of the cladding structure. Optimization of energy consumption both, during production of the element and lifetime through minimization of defective goods and improvement of tightness of the building envelope.
Training: the perennial problem faced by the composite industry in general and by the sandwich panel industry in particular is the near absence of long term and professional training of the workforce, both for students in the university, as it is not part of the taught curriculum in most European universities and for workers. The project will address both these shortcomings by developing a series of targeted lectures in electronic form for civil engineering and architecture students and by developing tailor made professional continuous training packages available both, online and in CD format. The EASIE project will also produce a virtual library available online to the public.
Sustainability: the adaptation of the existing building stock in Europe to climate change is a key problem particular in the new Member States. Sandwich elements are a consistent, quality controlled, industrially mass produced product. The EASIE project will enable a better understanding of their behaviour in service and through life. It will develop and propose procedures to allow easier incorporation/retrofitting of sandwich panels in the fabric of existing buildings and replacement or easier repair of defective elements. It will result in a product which is consistent, better understood with a reduction in raw material consumption by extensive exploitation of the potentials of all building components.
Durability: the project will enable an accurate prediction of the product lifecycle by determining “fit for purpose” state at any given time allowing the determination of remaining service time for existing constructions.
In addition to these scientific technical advances, the project will make substantial headways in changing existing mind-sets which prevent the wider adoption of sandwich panel technology across the industry. Despite decades of use in the field, sandwich panels are still considered a new, relatively untried technology. This is mainly due to the fact that sandwich technology is not part of the curriculum of most engineering courses and suitable training materials are not available for in service training of the existing workforce.
Project Results:
More detailed information can be found in the attached pdf-file!
WP1 focused on two areas, air permeability of panel joints (causing thermal losses) and structural effects of openings on panel assembly, which are of fundamental importance for the successful application and use of sandwich panels.
The work developed guidelines on good practice for panel joints with regard to water and air permeability and models for the assessment of strength of panels with openings as well as distribution of loads between panels with openings in a wall panel assembly.
WP2 was concerned with the development of the design by testing method and its applicability in parallel with the design by calculation method. The development of the thermal test method was completed and was validated through an extensive experimental programme and parametric study.
WP3 produced a substantial experimental database and an evaluation and analysis of the results for in-plane shear resistance to stabilize buildings, both in a conventional design with a steel framework and in a frameless building. A design model for panels under axial loads based on known values was developed. Guideline for good practice regarding sandwich constructions without substructure has been completed, consisting of 3 parts: Part 1: Design guideline, Part 2: Construction guideline and Part 3: Draft of amendment for EN 14509.
WP4 described the influence of ageing on the shear strength and on the wrinkling strength based on the information available from manufacturers and users of sandwich panels and on an in-depth analysis of the different faults and defects and the possible repair methods. The results of the artificial ageing tests and of the tests on old panels were analysed. Existing models on the development of the cross-panel tensile strength of the sandwich panels when exposed to natural environmental effects were reviewed and evaluated. Improvement of Design Expressions was first written in draft form on the basis of the first batch of experimental results before being finalised in November 2011. A model to evaluate remaining service life was produced. A new method for the in-situ repair of sandwich panels with blisters or local damage was developed and trialled.
WP5 focused on the production of eLearning resources for the improvement of the knowledge of the use of sandwich panels in buildings. An extensive list of electures were recorded and made available on the project’s website at www.easie.eu. A list of relevant literature and codes on sandwich panels for the major EU countries was collected. Guidelines of good practice were assembled on the basis of the information received from the industrial Participants.
WP6 focused on dissemination and use of the results. Ten e-newsletters were published on the project’s website. A User Guide based on the key results from the project was published in paper form and on the project’s website. Three user-focused industry workshops on the theme “Building with sandwich panels’ fast, safe and energy saving” were held in Zagreb, Croatia on 17th June 2010, in Barcelona, Spain on 24th March 2011, and in Krakow, Poland on 9th June 2011, with special regards to the needs of local industries. A post-project strategy was agreed by the Participants in order to manage the project’s legacy.
The project has contributed to standards in a number of ways in particular, through personal contacts and overlapping membership, by regular feedbacks to the European Committee for Standardisation (CEN) TC 128/SC11 and especially WG1, WG2 and WG5 who were dealing with the European standard EN14509 and to the European Joint Committee on Sandwich Constructions formed of ECCS TWG 7.9 Technical Working Group and CIB W 56 Working Commission. Major part of the EASIE work, in particular WP1 and WP2, are being incorporated into existing standards and guidelines.
Potential Impact:
The proposal has met most of the expected impacts specified in the call and listed in the work programme. The project addressed the objectives of the Framework Topic NMP-2007-4.0-6 Innovative added-value construction product-services. More specifically it has achieved major technical, economic, industrial, environmental and social improvements and advances which will diffuse across the European Union in the coming years. These have included in particular:
- The development and improvement of a highly knowledge-based construction processes and products, sandwich technology, which is mainly deployed by SMEs and especially used for the retrofit, refurbishment and maintenance of buildings, but also the opening of new market segments for sandwich technology by establishing formal fundamentals and broadening awareness through education and learning.
- The modernisation of a number of SMEs businesses by developing new construction knowledge-based services and products, improving their competitiveness with crucial impact on employment and growth and making available new technologies and industrial practices.
- The reduction of the impact of a number of construction technologies on the environment based on the optimum sustainable use of new construction materials in the form of sandwich panels, improving their production, installation, durability, reuse and retrofitting.
- A major contribution to technology innovation in the EU by addressing the urgent issue of rehabilitation and regeneration of many urban areas of Europe particularly in many new member countries, to help adapt buildings and infrastructures across the European Union to cope with expected change to climate change and withstand adverse weather conditions and to enable the construction industry to contribute towards the increasingly demanding targets in reduction of CO2 emissions.
- A contribution to knowledge-based upgrading by delivering an optimised product suitable for retrofitting of the existing building stock and also suitable for use in new built.
The results of the EASIE research have closed existing scientific gaps that have hitherto hindered sandwich panel construction from gaining a larger market share. This includes obvious shortcomings such as lacking knowledge about the effects of openings in sandwich panels, about the contribution of the sandwich building envelop to the global load bearing capacity of a structure and about the ability of sandwich structures to take axial loads. The industry has acknowledged the substantial impact that the project’s research has had on the sector.
The development of a European wide accepted test based design method has given producers across EU countries the freedom of acting according to their habitual design method ensuring comparability and will give the potential to solve specific application situations through sound engineering. The method will help to exploit the structural potential of sandwich panel further.
Deriving a sound design procedure including the log term structural performance of a sandwich element will strength the costumer confidence and give producers and engineers the possibility to design their product according to their needs.
The European construction sector is a major contributor to exports. This is particularly true for high added value products that require excellent engineering such as composite sandwich elements. The building material sector is recognizing a growing potential in emerging markets in developing countries and is diversifying. Many of these markets employ sandwich construction for structural and economic reasons. The high potential in energy saving that sandwich elements offer is not often perceived as a sales argument but becomes increasingly important during the lifetime and resale.
The market for exchange of the panels in the EU is large so the potential on the market should be high. However sandwich elements today only take a share of 10 to 15 % of the thin wall steel profile market. The results of the EASIE research and particularly its dissemination will help the sandwich panel sector to increase this share by eliminating formal, technological and sociocultural aspects hindering the sector to expand further. A further market penetration in the thin wall steel sector of only 10 % will lead to a doubling in turnover for the sector and will move the construction industry further towards a technology driven, progressive and modern industry sector.
There is a potential to achieve more advanced knowledge-based upgrading of existing buildings as the project has provided a substantial library of validated data regarding long term behaviour of sandwich panels and the development of additional elements for improving bearing structures applicable in refurbishment and retrofitting of old buildings. Validated methods of repair and maintenance will help to maintain and improve the existing, highly valuable building stock across the European Union.
Changes in construction practices are necessary to help adapt buildings and infrastructures across the European Union to expected changes in climate change and in particular to adapt to an increase in extreme weather events. The construction industry will also have to contribute towards the increasingly demanding national and international targets in reduction of CO2 emissions.
Half of all CO2 emissions are building-related and nearly a third of these come from housing. Over 10% of global CO2 emissions are related to the manufacture and transport of construction materials and the construction process. It is widely acknowledged that the greatest potential to reduce emissions in the construction industry sector is associated with the existing, occupied building stock.
By promoting an increasing use of sandwich panels for both the refurbishment of existing buildings and for new built, the project’s has contributed to a global reduction in the energy consumption of the building stock through improved thermal insulation and better controlled indoor environments.
The project has also contributed to an improvement in working quality and conditions. Training within EASIE has focused on activities which were essential to achieving the objectives of the project, which contributed to the professional development of the engineers and scientists involved and which contributed to the formation of a skilled workforce capable of answering the challenges presented by new technologies, new industrial processes and evolving national and European regulations, codes and standards.
The project has developed methods, based on sandwich panels, to better utilize existing buildings and to create new solutions and practices to use sandwich panels in innovative way in new constructions. This has, and will in future, lead to an expansion of the market of the sandwich panel industry and thus, will offer more work places in future in EU. The increased use of highly engineered construction systems will help in the trend of shifting the construction workforce from unskilled workers to a highly skilled workforce.
New methods to evaluate the service life of sandwich panels make possible to define more clearly the technical and economic value of the existing and new panels. The project will develop solutions to retrofit existing building stock based on sandwich panels in order to achieve the requirements for safety, thermal insulation and air and water tightness. It also may show solutions to reuse the panels in new applications.
The project was pre-normative in character but has contributed significantly to the standardisation activity in Europe. Standardization provides a harmonised basis for the manufacturing, design and use and thus, improves the climate of the competition market. It alsoimproves the quality of the product by defining exactly expressed requirements and by giving high-quality method for the verification of the required properties. The developments in European standardisation have also a direct effect on other export markets as often European standards are either amended as national standards or, where national standards are extremely weak or even lacking, producing in accordance with the European standard on sandwich elements gives major competitive advantages.
The project has also contributed to standards in several other ways, including feedback through analysis of best practice. The feedback has occurred through different standardisation committees including in particular the European Committee for Standardization (CEN) TC 128/SC 11 which is dealing with the European harmonized standard on sandwich panels. The developments of technical rules which have and will support pre-standard works are one of the project’s lasting legacy
Sandwich panels are manufactured by many companies in many countries throughout the world to a variety of national or regional manufacturer standards. However the normative and regulatory regimes under which they are designed and installed are fairly weak. The sharing of knowledge amongst panel manufacturers, designers, and installers which has been promoted by the Industrial associations which have participated in the project will improve the finished product and is an essential condition to increasing the competitiveness of EU companies and to extending their business beyond Europe.
The European community also carries with it the idea of European level solutions, and an important benefit of working collectively across national borders on problems, which have large-scale strategic importance, is that the solutions ultimately satisfy the European dimension rather than the purely national one. This also serves to influence, and helps to integrate national policies into a European framework by developing the core technologies under a community programme from which all members can draw. The numerous dissemination activities (user-focused workshops, user guide, enewsletters, industrial conferences) undertaken by the project have helped in this process.
To survive, grow and prosper SMEs must constantly innovate, developing new technologies themselves or obtaining new technologies through technology transfer. The central aim of the project was to expand their knowledge base and enhance the overall competitiveness of a large community of SMEs which have the capacity to innovate but with limited R&D facilities. The project has harnessed the skills and expertise of five major European Industrial Associations and Groupings (APIPNA, EPAQ, Pan and Pro Europe, SNPPA) which have a membership made up almost exclusively of SMEs and from the European Convention for Constructional Steelwork (ECCS) and has enroled the support of the International Council for Research and Innovation in Building and Construction (CIB) who are also focusing a major part of their activities on the needs of SMEs.
The Project has provided a comprehensive package of innovative technological products and training tools tailor made to the needs of SMEs. This has helped SMEs and their industrial associations:
- To acquire an enhanced capability to economically design and manufacture fit for purpose sandwich panels in new buildings but also in existing buildings.
- To deliver to clients a more competitive product able to accommodate the requirements defined by the clients of the construction industry as well as the requirements defined by harmonized EU standards.
- To broaden the scope and enhance the quality of European standards allowing better exploitation of the products properties giving further advantages over competing, labour-intensive and error-prone construction methods.
- To receive help and guidance in accessing and incorporating in design and production fast changing engineering practices and regulations, codes and standards
- To obtain scientifically based solutions to a number of issues which were previously dealt with through intuitive engineering judgment thereby reducing the potential margin of error and risk of failure and accident
- To operate within an improved climate for fairer competition within the industry resulting from level playing field across Europe and through increased certainty as to the “rules of the game” by ensuring the development of widely applicable standards
- To gain a better insight of, and influence on, national and European legislation with regard to product requirement and liability, environment, on-going development and research and end-use applications
- To benefit from training of staff, exchanges with a wide range of stakeholders across the European Union and privileged access to a range of data sets, models, design, guidance, best practice and generally user focused technical information
- To benefit from the internet-based E-Learning facility established by the project.
