Integral Engineering Design work with innovative and sustainable materials to benefit our clients. To demonstrate application and suitability of these materials we participate in a number of research projects as an Industry Partner. Most of our staff are also visiting tutors at local Universities and we are happy to provide CPDs to others in the Construction Industry. Some of our pioneering uses of materials are listed below.
Limecrete testing is currently underway at the University of Bath to confirm the optimum mix design which will be used on the Archway project. Limecrete has been chosen as an alternative to concrete to provide a floor which is breathable to protect the archaeology. Low strength limecretes (pure limes or low strength hydraulic limes) can provide a breathable surface however; the high humidity within the undercroft may make it difficult for low strength limecretes, which cure primarily through carbonation, to gain strength quickly enough. Several mix designs of varying water and pozzolanic content for breathability and compressive strength are being tested to determine the optimum mix for this application. Sample were cast in the undercroft to check that the limecrete can achieve the initial set in the high humidity environment.
Integral Engineering Design have pioneered the use of carbon fibre reinforcement to strengthen existing concrete framed buildings. The bonding of carbon fibres to existing concrete structures provides an excellent retrofit solution for strengthening existing structures and avoids the use of cumbersome downstand beams. Integral developed solutions in conjunction with Dr Antony Darby from the University of Bath who authored the Concrete Society’s TR55, the UK Design Guidance for Strengthening Concrete Structures using Fibre Composite Materials. We have successfully used Carbon Fibre on a number of projects including Temple Circus, Bristol and 20 Manvers Street, Bath.
Brettstapel uses low grade softwood timber with driven hardwood dowels to create a structural timber panel with extremely low embodied energy, and a high quality visual finish. Local Welsh spruce and Douglas fir were kiln dried for use in the structure of Coed y Brenin, which is the first ever Brettstapel building to use UK sourced timber. This project has proved to be a test case that has increased confidence in this method of construction, which is already used widely elsewhere in Europe.
Integral have been, for some years, one of the industry partners developing the use of pre-fabricated straw bale panel systems resulting in a UK patent. With our co-founders and the University of Bath we have developed a fully prefabricated panel system that exceeds current Building Regulations. This has entailed a number of research projects funded by the Technology Strategy Board and we have successfully used the panel in education and housing projects.
Rammed earth is an ancient construction technique recently rediscovered as a modern sustainable building material. Research has focused on the fundamental behaviour of rammed earth in terms of unsaturated soil mechanics. Our latest rammed earth project is The Gillyflower.
The brief for one of our domestic projects, the Chalk House, was to use old technology with modern methods of construction. A careful integration of chalk load bearing structure and timber frame enabled a truly original building to be conceived and delivered. The site was located on natural chalks. The subsoil was tested at the University of Bath for compressive strength and moisture content to check its ability to be used as a rammed soil to construct the 5m walls. The chalk showed range of capacities from 1.25 -1.7N/mm2 which was deemed adequate.
Photograph: Testing limecrete for the Archway project