Practical implementation of robotic brick-laying

Bricks are a traditional building material that has been used for building construction since ancient times, with a long tradition of skilled craftsmanship.

From being used mainly for the load bearing structure, bricks are in today’s building construction almost exclusively used as a façade material.

The popularity of this material has been rising in later years, partly because of its low maintenance requirements, but also because of its naturally varied expression.The brick laying craft is still performed in a very traditional, manual and labour-intensive way.

As in many other parts of the building sector, there are therefore a large potential for a more efficient work process and decreased manual workload.

Robotic brick-laying, and an efficient digital information flow from designed building to its construction, also opens up for new possibilities for variation, advanced expression, and maybe also function integration in the design.At the Construction Robotics Lab at LTH robotic masonry has been studied in a series of different research projects the last 2-3-years.

In earlier projects, a basis for a digital information flow from the first architecture sketch to when the robot places a brick at the construction site has been developed.

Robotic brick-laying has also been investigated thoroughly in the lab environment, where bricks have been stacked physically to build a structure based on a digital design model.

Initial test for applying mortar has also been conducted.The challenge we now want to address is to transfer this technique from the lab to the constructions site and to build a masonry structure using an industrial arm robot out in the field. The robot should also apply mortar in a controlled and precise way in order to create a stable and permanent structure.

The advantage of using an industrial arm robot is its flexibility and possibility to conduct may other tasks at the building site.

The project will be completed by the robotic construction of a masonry structure at the visitors centre for the development area Science Village in Lund, between the research centres MAX IV and ESS.In order to implement this, mainly the technique to apply mortar has to be further developed. This also includes developing the actual recipe of the mortar so that it fulfils a number of criteria.

Todays mortar is developed for manual application and we need to modify it to be suitable for robotic masonry. The mortar needs to be possible to pump and to be able to be applied by a tool on the robot.

It also needs to be of a quality that gives good adhesion between the bricks and evens out the unevenness of a standard brick.

The mortar also needs to be applied in such an amount and in such a pattern on the bricks that enough adhesion is obtained while still giving an attractive look of the finished piece, so that no superfluous mortar drips down the structure.

To achieve this, the joint probably needs to be thinner than in today’s manual brick-laying, where the mason are able to scrape of the superfluous mortar and tidy up the joint.

A series of experiments will be design and performed for the mortar and its application, where different recipes are tested and the adhesion, appearance, stability and strength of the whole structure is investigated.The project also includes the design of brick structures for the experiments and some development of the digital information flow, where further steps from design model to construction can be automated.

For the actual construction part of the project, the logistics of bringing the robot out to the construction site, and the configuration of the building site, also needs to be investigated.

This includes, for example, transportation of the robot in a dedicated container, the positioning and connection of the robot at the building site and the configuration of suitable safety measures.To summarize, the goal of the project is to take the last steps to realise robotic masonry on site for a small building