All the Small Things

Nick Constantine, senior surveyor at Cavendish Maxwell, looks at how advancements in building material technology are changing how we view the fundamentals of construction.

As many of the world’s leading technological hubs maintain focus on transforming into smart cities that use information communication technology (ICT) and the internet of things [loT] to integrate city-wide infrastructure, the buildings we live and work in are also evolving to become smarter and more intuitive to the user’s requirements.

The spotlight is, and has been for a number of years, firmly set on how smart building systems can enhance the user experience and increase energy efficiency. Building management systems (BMS) are widely used in the UAE, with varying levels of integration, enabling monitoring and control of a building’s mechanical and electrical installations even from a remote location, using the cloud. Automation systems provide even greater control than BMS systems, providing the user with control over almost all aspects of the building. These developments include being able to operate the lights on the property remotely to ensure it is illuminated prior to arrival, or the ability to run yourself a bath ahead of time while travelling home. While automated building systems receive much of the media attention due to the direct connection they have with our everyday lives, considerably less attention is given to the advancements in building materials that form the very structures within which the smart systems are installed. Advancements in building materials do tend to develop and be adopted much more slowly in comparison to technological advancements in building systems. This is for good reason, as there is much less risk of harm being caused as a result of a building system malfunctioning or ultimately failing. The same cannot be said for defective building materials, which at the very least can present a risk of injury and at worst have life safety implications with often grave outcomes.

While this does seem to impede the application of these materials within buildings on a wider scale, it has not prevented the research and development (R&D) of advanced building materials. Traditional material components are constantly undergoing modification to improve the performance of buildings. Significant advancements are being made as material scientists examine materials in microscopic detail, quite literally. Nanotechnology presents one of the greatest potentials for building material improvements in the future. A nanometre is one billionth of a metre, and by examining materials on this scale and altering, manipulating or combining them at this level, it enables enhancement of the material’s properties, while avoiding the usual accompanying undesirable characteristics. For example, materials which are high in strength are also typically heavy; this could potentially be overcome by using nanostructured materials.

The study of nanotechnology has produced carbon nanotubes, nanocomposite coatings with increased resistance to scratching, and even superhydrophobic materials which repel liquids while collecting dirt from the surfaces, providing a self-cleaning surface. Self-cleaning glass technology could present huge operational cost savings in this region, where glass facades are highly used. The Burj Khalifa has over 25,000 glass panels, requiring specialist equipment to clean and taking approximately three months to complete a single cleaning cycle, all of which could be avoided with this technology.

“There is a requirement for huge investment in R&D of the product itself, and the new materials also require the development of new manufacturing methods, new machinery and retraining in the industry”

While the properties of materials are being improved in this manner, materials are also being developed which react to environmental conditions without intervention, giving rise to smart building materials.

Thermochromic coatings and glazing systems have been available on the market for some time now, and these products react to heat from direct sunlight, changing colour in coatings and tinting glass according to the intensity of sunlight on their surfaces. Thermochromic glazing can provide an effective means of reducing thermal gains on internal spaces and alleviating demand for cooling. The technology is expensive in comparison to traditional low-emissivity glazing, and in situations where the glazing does not receive enough direct light, the material may not respond as required and result in potential issues with internal glare.

Increasing longevity of building materials is one of the largest drivers for innovation in the construction industry. Concrete, the main construction material used in GCC structures, is prone to cracking over time. Once cracks establish in the surface of concrete, it can lead to further deterioration, accelerated by carbonation or chloride attack. Depending upon how widespread the problem becomes, it can be incredibly difficult and expensive to remediate and may lead to structural integrity being weakened to an extent that failure of structural members is possible.

Nanopolymer aggregates incorporated within concrete mixtures have been engineered to activate when the PH of the concrete becomes too acidic, returning the concrete to a more neutral PH state and reducing the potential for reinforcement corrosion and concrete deterioration. In the Netherlands, there has been a further step taken with the development of bioconcrete. This material is currently being tested in a number of scenarios, and has already drawn a lot of attention for its potential. The bioconcrete mix has added bacteria and calcium lactate dispersed throughout it, which can then lie dormant in the finished material for up to 200 years. Once the material cracks and the bacteria is exposed to moisture, it is activated and begins to form limestone, infilling the cracks and preventing further moisture ingress and deterioration.

“The study of nanotechnology has produced carbon nano tubes, nanocomposite coatings with increased resistance to scratching, and even superhydrophobic materials which repel liquids while collecting dirt from the surfaces, providing a self­cleaning surface”

While material innovations are presenting credible options for the improvement of buildings in the future, it is not only risk of injury which hampers the development of a new smart building material. There is a requirement for huge investment in R&D of the product itself, and the new materials potentially also require the development of new manufacturing methods, new machinery and retraining in the industry. The difficulty therefore is knowing which technologies will make it over these hurdles and be adopted – and which will end up in the skip.