Bomb-resistant quick-fix wrap can prolong life of concrete

Materials World magazine
28 May 2019

A new stick-on material has been created that can make buildings stronger and bomb resistant. Shardell Joseph reports.

A ready-to-stick wrap made of glass-fibre has been invented that can be used on buildings and columns to improve strength and extend the lifespan of concrete. Created by materials scientists at Nanyang Technological University (NTU), Singapore, concrete pillars wrapped in the material called fast wrapping reinforced polymer (FasRaP) can withstand an additional 80% load.

NTU partnered with infrastructure specialist JTC and consultancy company Prostruct Consulting Pte Ltd to jointly develop the FasRaP technology with the potential to rehabilitate ageing infrastructure in urban cities including buildings and bridges, repairing cracks and delamination of concrete.

According to NTU, the technology uses commercially available glass-fibres with a propriety glue-like resin, which acts as an adhesive for the wrap. Easily applied on pillars and walls, NTU claims it is possible to complete the task with three workers. This is compared with conventional fibre-reinforced plastics (FRP), which typically requires a team of six workers to install, as it needs to be manually applied on site.

‘Our invention allows companies to save on manpower costs, increase efficiency and make structural reinforcement much easier to execute,’ said NTU School of Materials Science and Engineering Associate Professor and Lead Project Investigator, Ng Kee Woei.

‘This will help them to meet future building standards and prolong the life of older buildings and structures as Singapore and other urban cities age.’

In addition to improving the strength of buildings, the material also withstands blasts, giving greater protection to structures that provide essential services, such as hospitals, heritage buildings and premises with large volumes of people. The team also claimed that in comparison to other methods, such as steel reinforcements, FasRap is much cheaper.

JTC Group Director of Engineering, Calvin Chung, stated that the purpose behind developing the FasRaP was to address challenges faced by the construction industry, such as manpower constraints and quality control.

‘The development of new advanced materials such as FasRaP will help us meet the growing demand for the repair and rehabilitation of ageing infrastructure in Singapore by significantly reducing the time and improving the quality of installation, thereby increasing productivity and cost efficiency,’ Chung said.

Hardening when exposed to light, the material is easily pre-fabricated in the factory and packaged into a ready roll of sticky wrap, similarly to double-sided tape. The wrap can then be applied and left to dry in the sun for a few hours, which will form a hard protective layer on top of the concrete. Once the material is applied, it can be plastered and painted over like a normal wall.

Testing with a blast

Founder of Prostruct Consulting and certified Blast Consultant, Ang Choon Keat, said FasRaP was tested at the firm’s lab. The product’s performance was analysed in industry-standard blast and load tests, which NTU said proved to be just as strong as conventional FRP.

Comparing a bare concrete pillar without reinforcement and a pillar wrapped with FasRaP, NTU said the tests showed the latter could withstand an additional 80% load. A wall wrapped with the material was left largely undamaged despite a luggage bomb exploding around 10m away.

‘Besides reinforcing existing structures, we have also conducted blast tests and demonstrated that FasRaP is suitable for strengthening any walls and structures against blasts,’ said Keat. ‘This is an important application in view of the Infrastructure Protection Act passed by the Singapore Parliament in October 2017.’

It’s a wrap

Now looking to commercialise the material, the team has intellectual property protection in the form of a technology disclosure filed through NTUitive – the NTU commercialisation and innovation company.

In addition, NTU has stated that there have also been talks with FRP manufacturers and industry contractors using FRPs. JTC also aims to identify suitable infrastructure projects to deploy FasRaP, in order to accelerate its adoption and commercialisation.