The Trouble with Concrete - Challenges and Solutions

Over the summer, the Ashurst Construction team explored a number of ways in which the construction sector can become greener and how we, as legal advisers, can help in the transition.  A topic that kept coming up was concrete and we could not conclude our series without taking a closer look at its use, possible alternatives and solutions to the problems its use creates. 

Why concrete is a problem

Concrete is said to be the second most used material on earth after water and the second-largest emitter of carbon dioxide. Allegedly, if the cement industry were a country, it would be the third largest emitter of carbon dioxide globally, behind only China and the US. 

It feels like something of a paradox to acknowledge that our overuse of this single material contributes roughly 8% to global carbon dioxide emissions – more than triple the levels caused, for example, by the use of aviation fuel. Air traffic pollution is frequently cited as a major polluter (see, for example, the Court of Appeal ruling earlier this year that a third runway at Heathrow was unlawful on environmental grounds) whereas concrete, it is fair to say, does not get quite the same level of press coverage!

Alternatives to concrete

There are many possible alternatives which have carbon dioxide and efficiency benefits. New materials, including new materials being developed by the likes of Pavegen, which I referred to briefly in my last article, are in development. A few interesting examples include:

• Glass fibre reinforced concrete (often referred to as GFRC), which consists of concrete, sand, alkali-resistant glass fibre and water. This material has good elasticity, enabling moulding of thinner and lighter pieces of façade and is notably in use on the on-going construction work at Barcelona's iconic cathedral, the Sagrada Familia.
• 3D concrete printing was unveiled in Switzerland last year, with an installation of the first robotically 3D printed concrete columns. The columns, forming an artistic stage, were said to be fabricated without formwork and printed to their full height of 2.7 metres in 2.5 hours. This new 3D printing process, known as layered extrusion printing, used custom software to individually design each column. According to Arch Daily, this process has the potential to greatly improve the efficiency of concrete construction.
• In September 2019, the Massachusetts Institute of Technology unveiled research which suggests a new way of manufacturing cement which can eliminate emissions altogether. The process involves use of an electrolyser: pulverised limestone is dissolved in acid produced by an electrolyser. High-purity carbon dioxide is released and calcium hydroxide precipitates out and forms a solid, which is then used to produce the cement. The pure carbon dioxide, the research indicates, can be sequestered easily: it can be used to produce value-add products such as liquid fuel to replace gasoline, or used for applications such as oil recovery or even to make beverages and dry ice.

In an industry that has lagged behind in terms of productivity and is so stymied by time and budget overruns, disputes and the entrenched use of traditional procurement routes, it is sometimes challenging to see such innovation in a tangible sense. However, change is already occurring: the McKinsey Global Institute, in The next normal in construction (published June 2020), highlights that new entrants to the industry will continue to push forward already emerging disruptions: from the use of new material technologies to the digitalisation of products and processes. They are firm in their view that fundamental change is happening and we will see an industry that looks very different in as few as 5 to 10 years.

Nevertheless, even in the face of radical change, the prevalence of concrete as a top choice of material is unlikely to change anytime soon. Advocates of concrete use point out that we can take steps towards reducing our carbon concrete footprint without having to turn entirely to new alternatives.

There are a number of perceived benefits to the use of concrete: it is completely fire resistant (and, in the post-Grenfell landscape, this is of importance); it is recyclable (at the demolition stage concrete can be reused or crushed to be recycled); it is resilient to weather; it comprises materials which are, in 80% of cases, used within 30 miles of their original extraction; and it can contribute significantly to the reduction in carbon emissions over the life of a building, as the thermal mass of concrete can add to the energy efficiency of a building by reducing heating and cooling loads, and therefore also running costs.¹ Such benefits are arguably increased by the use of precast concrete, which is manufactured off-site.

Precast concrete and off-site manufacturing 

Precast concrete is far from a new concept but it can and is used successfully as part of a sustainable building. It is also on the radar of the UK Government, who have acknowledged its importance in addressing the current housing shortage.

According to British Precast, precast concrete has many sustainability benefits, such as:  

• Quality control: all precast concrete is produced in factories and is mostly covered by an ISO 9001 quality management system. A great deal of attention is paid to quality and uniformity: architectural precast concrete, for example, will often need to be uniform in both texture and colour. Good quality management, and the ability to reuse quality moulds, inevitably results in less waste.
• Responsibly sourced materials: the industry has adopted the sourcing standard BES 6001, since it was launched in 2008. This requires the various elements of concrete to be responsibly sourced. Three quarters of producers are now producing concrete meeting the responsible sourcing requirements of BES 6001.
• Efficiency: one of the key benefits lies in the efficiency of the manufacturing process, which has seen a 95% reduction in waste to landfill and a 40% reduction in water use in just over a decade.

Legal issues 

Changing the way the sector uses concrete raises plenty of legal challenges:

• Will classic design and build contracting reduce in its use to pave the way for design for manufacturing and assembly (DfMA)? It seems likely that a procurement route which allows for greater multi-party collaboration from an early stage will be essential. RIBA, in their guide on DfMA, state that buildings need to suit specific uses, users and locations and that traditional construction and procurement methods have acted as a barrier to harnessing the benefits of off-site manufacture and production. DfMA, they say, changes this.²
• A logical move would be to new types of contract, or contracts such as the NEC4 Alliancing Contract, and away from lump-sum, "contractor-takes-all-risk" design and build contracts. Indeed, insurance-backed alliancing procurement routes are on the UK Government's radar. One does not have to look far to find commentators appealing for a fundamental realignment to the structuring of construction contracts. However, there is an assortment of issues that will need to be addressed: apportionment of risk in multi-party contracts; transfer of title will need to be carefully considered where large components of a build are manufactured off-site and to new methods; the use of integrated project insurance to guard against the industry's biggest risks of time and cost overruns; and the use of project bank accounts to manage payment and ensure parties throughout the supply chain are paid on time, and so on.
• Early contractor involvement is a key feature of off-site manufacturing, so the use of two-stage tendering, pre-construction services agreements and/or early supply agreements will need to be facilitated.
• Advance payments and therefore the use of advance payment bonds will become increasingly commonplace. At the moment, advance payment bonds are typically on-demand in nature, and therefore expensive, but that may need to change.
• Bank and parent company guarantees and bonds may need to be more robust and of greater value. Unless alternative procurement routes become well-established, the cost of bonds and guarantees could rise. In an insurance market where costs are already high (and going upwards) this will need to be carefully managed and considered when parties assess their risk.

Final thoughts

Creating a greener built environment will depend on more than tackling the problems concrete presents. But, as discussed above, there are ways in which its impact can be mitigated. The legal sector also has a part to play in ingraining sustainability in the contractual machinery.

In conclusion, it's worth observing that many of the legal issues mentioned above are relevant to the challenges facing the construction industry more generally. Digital and technological advances, a call for greater collaboration and new approaches to risk allocation all mean that a fresh way of doing things is needed but such change can only materialise if all stakeholders in the industry (clients, contractors and funders) embrace it, and soon.

Author: Matt Pearson

1. Data sourced from a report entitled Offsite Concrete Construction: A guide to the design and construction of precast concrete in buildings, published by the Mineral Products Association and British Precast (2019).
2. Joint publication by the Royal Institute of British Architects and the Offsite Management School: RIBA Plan of Work 2013: Designing for Manufacture and Assembly (2016).