Lego and jigsaws

Clay Technology magazine
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21 Oct 2016

Inspiration from Lego bricks and jigsaws could see full-size buildings constructed in the same way. Ellis Davies reports.

Fast and cost-effective construction is desirable in the building of any structure, with building materials, labour and time all contributing to the overall cost of a project. With this in mind, two new types of brick have been produced to streamline the construction process. The University of Luxembourg (UL), in collaboration with building materials manufacturer Chaux de Contern, have developed bricks that slot together like Lego blocks, with no need for mortar. Similarly, Armed Omega, Mexico, and architect Jorge Capistrán debuted the Block ARMO in 2015 – a brick system consisting of six pieces that are self-supporting – with a hope to providing new construction systems to contribute to Mexican society.  

Big Lego

The building elements produced at UL are made from concrete with aggregates lower than 16mm. Shahriar Agaajani, Managing Director of Asars Constructions, Luxembourg, recently received an international award from the International Masonry Society, UK, for his findings regarding the characteristics of walls built using these materials. The research showed that the interlocking system enables the construction of a whole storey in one day, able to carry the load of a superstructure immediately. 

Professor Danièle Waldmann-Diederich, head of the Solid Structures research group at the University of Luxembourg, told Clay Technology, ‘The new bricks are designed to guarantee better resistance. They are able to support greater loads than conventional bricks and are produced to build load-bearing walls, not simple partition walls.’ 

Prototype blocks produced by Chaux de Contern were tested under shear, centric and eccentric loads of up to 180 tonnes, with the results showing high structural performance, without the need for a mortar to distribute pressure. 

The blocks do not have a standard shape, as Waldmann-Diederich explains. ‘The shape of the block is determined by a cross analysis of thermal and mechanical resistance. The thickness and the provision of the blocks are designed to limit the existence of the cold bridges and deliver efficient stress distribution inside the block, resulting in an optimal load bearing capacity.’

The bricks are manufactured mechanically using an inverse framework. Concrete is poured into the frame and an automatic vibration compression system is used to compact the concrete.

Waldmann-Diederich explained the advantages of the new blocks. ‘They guarantee high-speed execution, good mechanical resistance and a sustainable use of raw materials. Furthermore, considering the total life cycle of a structure, the use of dry-stacked masonry elements permits a complete deconstruction of walls without degradation of the blocks. There is no need to recycle the concrete elements – they can be directly reused at another construction site following the logic of the circular economy.’  UL also claims that the bricks are cost-effective and profitable on a total analysis.

The project is to be followed up by UL, Chaux de Contern and ASARS Constructions to further develop the blocks for market. The bricks are expected to be commercially available by the end of 2017, for use primarily in two-to-three-storey buildings. 

Housing puzzles

Armed Omega, based in the town of Puebla, Mexico, officially introduced Block ARMO at Mexico’s National Entrepreneur Week in 2015. The system is also assembled without the use of a mortar, but uses six variations of jigsaw-like blocks that fit together securely. 

Block ARMO began as a project to modernise traditional building systems in an effort to solve the housing shortage in poor communities, with a focus on quick and easy builds. Armed Omega says that it aims to provide an adaptable product for housing and packaged modules that enable growth. 

The blocks are manufactured using local and recycled hydraulic concrete, or concrete-sand. Armed Omega claims that the production process uses up to 30% less water than conventional brick making, and the use of local materials reduces transportation costs and related pollution. 

Cavities in the bricks can be used to fit mechanical, electrical and plumbing services, and are shaped so that they can only be put together in one way, meaning that a worker could easily be trained to use the blocks. The company says that the use of Block ARMO cuts construction time by up to 50%, and that the system can be used to build a 25m2 room in two hours.

The system is designed to be a viable alternative method for the construction of social housing. With production, transportation, and labour costs low – amounting to 20% less than average construction costs – Block ARMO has already proved to be an effective solution. Since Capistrán first developed the system in 2009, 300 homes have been built in Sierra Negra, Puebla, using the blocks. Buildings constructed with the bricks are also able to stand up well to earthquakes, making them suitable for disaster prone areas. 

Once a wall has been built, it is reinforced with steel rods inserted into the structure every 80cm, followed by poured concrete. The bricks can be used to reproduce the decorative features of traditional brickwork, such as ledges and flowerpots. The company is looking to diversify by working on the decorative elements of the system, adding various finishes, colours and textures to give the blocks the appearance of traditional brick. Armed Omega is also seeking to bring the product to the global market. 

Quick, easy and efficient construction methods, such as these innovations from UL and Armed Omega, could provide a cost-effective solution to housing shortages and emergency housing – an innovative step in the construction industry.