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Analysis

Breakthrough in Concrete for Downstream Applications

Wed, 01/22/2014 - 10:32

Two graduate students, Peter Brewin and William Crawford, had an innovative idea that a few years later became the foundation of a company. “We came up with a concept that enabled us to rapidly put up concrete surfaces, for which we developed a new material that we called Concrete Canvas,” explains Peter Brewin, Director of Concrete Canvas. This groundbreaking material technology allows concrete to be used in a completely new way. Concrete Canvas consists of a threedimensional fiber matrix containing a specially formulated dry concrete mix, and a PVC backing on one surface of the material that ensures the material is waterproof. It hardens on hydration to form a thin, durable water proof and fire resistant concrete layer, and can be hydrated either by spraying or by being fully immersed in water. “We control the density of the dry mix. Adding too little or too much water would mean that the strength of the material will be below specifications,” says Brewin. “The fiber matrix of Concrete Canvas fills the gap between the two surfaces, therefore there is no space for additional water to get in and the dry mix cannot flow out.” The standard Concrete Canvas product takes between one and two hours to dry out. If the product is being used in very hot environments, such as the desert, then the mix can dry out in as little as 20 minutes. However, it is possible to add retardants to the mix to delay the time it takes to dry. “A conventional Portland-based concrete reaches 80% of its strength in 20 days, but in weather conditions averaging 25°C, the Concrete Canvas mix can reach 80% of its strength within the first 24 hours. Once set, the fibers reinforce the concrete, preventing crack propagation and providing a safe plastic failure mode,” says Brewin. Concrete Canvas is used in a variety of civil infrastructure applications, such as ditch lining, slope protection and capping secondary containment bunds.

Concrete Canvas was partly funded with the money its founders won in several technology competitions. At first, they began developing inflatable concrete shelters, a relatively small business that continues to date, but Brewin and Crawford soon realized the huge market potential their invention represented. “We started off by going to the military and then moved to railways in the UK as it is a better market. The railway industry is all about speed and safety, repairs need to be done overnight with as few people as possible, rather than shutting down the railway line,” tells Brewin. Once Concrete Canvas successfully entered the railway sector, it began looking for other engineering applications in the UK and expanding its activities overseas. The company has done significant work in the South American mining sector in countries such as Chile, Peru, Colombia, and Brazil. It is now looking at opportunities to enter the Mexican mining and petrochemical industries. The fact that the product can be deployed by small teams in minimal time is a very attractive feature for the mining and petrochemical sectors, given how dangerous these environments are. The fewer people there are and the less time they spend on site, the less risk there is of an accident. The company also entered the UK’s refining and petrochemical sector about 18 months ago and has experienced rapid growth since. Brewin says that Concrete Canvas has already been deployed in six out of the UK’s eight refineries, while the company has already had conversations to enter the other two. The main application for Brewin’s product in the refining and petrochemical sector is bund lining for containment around storage tanks.

Bund lining consists of putting clay and earth banks around a tank to contain hydrocarbons. However, a common problem with these is erosion. Covering bunds with Concrete Canvas helps by improving resistance to leachate. “Concrete Canvas’ material is twice as hardwearing as traditional concrete, it does not crack, and it can be put up quickly with little labor and equipment. An installation can usually put up about 800m2 in a day with six people at work. This way, clients do not have to worry about bund lines eroding away as these are now covered by a hard concrete surface that withstands the weather. It also has the advantage of stopping vegetation growth, so clients do not have to clear the undergrowth every growing season,” says Brewin.

Because a concrete cloth’s structure mechanically controls the amount of water that can get in, the product can also be used underwater. Similarly, the cloth does not use any steel reinforcements, it uses synthetic reinforcements instead, meaning that it has no components susceptible to rusting. According to Brewin, the underwater application is quite complex and it is not a market the company has significantly pursued so far. Concrete Canvas did already work on a subsea pipeline in Qatar. Brewin recounts how a roll of his product was dropped from the back of a ship for a diver to wrap ducts in concrete cloths. In this case, the client wanted enough time for the diver to cover the pipes, so a retardant was added to the material to slow down the initial phase of the reaction and give the diver seven working hours. The company’s recent works in the oil industry also involved a project in Scotland, where a pipe was damaged, needing to be repaired and protected with concrete. Brewin explains that using poured concrete on this project would have entailed building a dam as most of the pipeline was submerged underwater during high tides. Concrete Canvas eliminated this step, resulting in lower costs and simpler logistics. “We rolled the cloths into sizes that were small enough to be handled by one person and the workers just wrapped these around the pipe at low tide. The job was done in under a day without having to dam the estuary,” says Brewin.

Brewin does admit his product’s relatively short existence in the marketplace can be a matter of concern for potential customers. Concrete Canvas is constantly subjected to specialized tests in the most rigorous ways possible, and it has proved to have a strong hydrocarbon resistance. “We have all sorts of independent certifications to back up our claims, and we can provide support dating back six years. However, we cannot provide data from 50 years ago, as we do not have an installation that old. It is difficult to convince people to try something new,” says Brewin. Nonetheless, he sees his company as having succeeded because it provides a completely new solution. “Major oil companies are willing to try Concrete Canvas’ material as its advantages outweigh the lack of long-term information surrounding it,” says Brewin.