Improving concrete preparation productivity on large scale outdoor applications Transportation infrastructure is vital to the health of the UK economy. Whether it’s commuters driving on motorways every day, or tourists travelling by air, we rely on transport networks to get us from A to B.  Consistently maintaining this critical infrastructure can be difficult — Citroen, for example, reported that work on fixing potholes across the UK cost £93.7 million in 2022. People still need to travel on a daily basis, so how do we effectively repair this infrastructure without disrupting day to day life? Here Tom Dunn, vice president of sales at surface preparation expert National Flooring Equipment, explores the role of surface preparation in large outdoor applications. Effective surface preparation plays an integral role in maintaining critical transport infrastructure such as highways, bridges, parking structures and airport runways. The surface must be in good condition to ensure the safety of people using them, as well as ensure that the floor has the durability to withstand vehicle and pedestrian traffic, as well as different weather conditions. While contractors often understand the importance of maintaining these spaces, completing the work without causing disruption to travellers can be challenging. McKinsey & Company estimates that large scale construction projects take 20 percent longer than scheduled and finish up to 80 percent over budget. From experience, these unexpected delays could be caused by a number of factors, such as weather delaying work, or a lack of preparation before arriving to site. However, sticking to the budget and client deadline is not impossible. By taking the time to plan the work effectively and choosing the right tools for the application, contractors can deliver high quality surface preparation at any scale. Preparation is key When starting any project, contractors should consider how to meet client expectations while adhering to the outlined deadline and budget. This is particularly important on large sites with regular traffic, because customers often want to limit disruption as much as possible. Taking the time to efficiently plan before arriving on site is therefore integral to surface preparation success. By visiting the site before work begins, contractors can understand the size and scope of the project, the condition of the existing floor, its current covering and the client’s specifications. For example, in large outdoor applications such as airport runways, highways or car parks, contractors must communicate with the facilities manager to clear the area of pedestrians and vehicles before commencing work to ensure safety. Some circumstances require entire site closure and in other instances contractors may be able to complete the work in stages to limit disturbance. For example, repairing the floor in multi-story parking structures one level at a time could give contractors time to complete the work efficiently without closing the entire structure. It’s important to accurately estimate the project timeline if required to work to tight deadlines, for example when working in high traffic areas. Sticking to the deadline might mean working in challenging conditions, such as in rain or at night. Plans must ensure the team can safely work through different weather conditions, darkness and high or low temperatures so that contractors allow enough time to complete the work without rushing it. Choosing a machine Once the project goals and timeline are finalised, contractors can determine what equipment or machinery they require. Larger projects usually require heavy duty ride-on scrapers that have a faster removal rate and are better suited to removing heavy goods like industrial epoxy with aggregate. Walk behinds may be more suited to applications such as weight-restricted bridge decks or around tight corners and hard-to-reach areas that a ride-on would have difficulty targeting. A combination of machines may be necessary when the site has varying levels of surface hardness, thickness, and complexity. For example, a ride-on scraper may be more efficient in removing large areas of material, while a walk-behind scraper may be more effective for precise removal during edge work. Additionally, achieving the desired surface finish may require different processes. For example, shot blasters can efficiently remove coatings, adhesives, and contaminants from vertical or horizontal surfaces. They can also create a surface texture that improves adhesion of coatings or to produce a non-slip surface. Scarifiers are useful where more aggressive treatment is necessary, such as removing thick coatings, roughing up smooth surfaces, or levelling uneven surfaces. Consider which fuels will be most appropriate during the project. In large outdoor spaces, an electricity supply for plug in machines may not be easily available, so diesel or propane powered machines might give more freedom. In any project, safety must be a priority for machinery operators and other contractors on site. Areas undergoing work should be physically cordoned off to prevent the public from entering the site. During ongoing work, contractors can also select equipment with added safety features to protect workers on site. For example, some ride-in scrapers feature light curtains to outline the movement of the machine. Choosing a ride-in machine with a positive air pressure cab can also protect the operator, reducing dust inhalation and enabling them to work in different conditions. Maximising uptime Choosing the right equipment is vital, but learning how to use it effectively is key to maintaining productivity once on site. By approaching the equipment supplier for training, contractors can understand how to set up and use equipment to increase productivity and ultimately create a safer working environment. For instance, setting up the angle and pitch of a blade can impact covering removal rates — understanding how to properly angle the blade for the covering could be the difference between quickly removing the coating and struggling to remove anything. It’s important to follow advice regarding maintenance, especially during longer projects, to minimise downtime. Counties spend millions each year on infrastructure maintenance to ensure that people can safely and efficiently travel around the country. So, when conducting repairs, laying new coverings or completing new outdoor projects, contractors should prioritise surface preparation to deliver a surface that will deliver long-lasting strength and

Traditional materials such as Portland stone may have been pushed out of the mainstream by concrete and steel, but nothing beats this natural material, says design and construction specialist Dan Grimshaw. “It may be old as the hills but is still a viable option for eco-conscious builds and can still play a significant role in an increasingly high-tech industry, says Dan from Beam Development, who has been working on premium residential projects for more than 15 years, “The mining of stone for building material is a relatively green process because there is no trapped carbon released during extraction. Unlike with some building materials, greenhouse gas emission is limited to the equipment used and does not produce any wastes. “Stone is a natural building material, free from pollutants that can cause various symptoms among workers in some modern buildings. It doesn’t need chemical treatment to make it waterproof, and with the appropriate fixing material, is an environmentally friendly option.” Inspired by the aesthetics of designer Axel Vervoordt, whose work combines contemporary and old materials, Dan personally sourced 2.4m³ block of Portland stone from Dorset to be used as a hearth as part of a restoration project in London’s Mayfair. “This beautiful, ornamental stone is classic but contemporary and its neutral colour allow it to work with a variety of colours and furnishings, and is at home whether in a minimalist apartment or a Georgian town house,” added Dan. “We chose Portland stone for this project, because of its soft grey tones which create a natural, pared back but aesthetic look that fits with the feel of the house, and that can be cut easily and shaped into various sizes and designs.” Portland stone is used extensively in some of Britain’s most notable structures from St Paul’s Cathedral to the Apple store on London’s Regent Street, and continues to be used in homes today, particularly for fireplaces, staircases, and flooring. When it came to choosing the right stone, Dan, along with architect Reginald Verspreeùwen from RV Architecture, visited Albion Stone on the Isle of Portland to identify the bed and cut they were looking for and then set about finding a block of a suitable size. “We spent two or three amazing hours – like kids in a sweet shop – looking at all the different stones, before hitting upon a 1.2 tonne piece of premium quality, fine grain basebed stone that ticked all the boxes.” The Portland stone hearth which will be the centre piece of a two-storey atrium with a biofuel heater and chimney stack above, is set to be marked and cut and then transported to Mayfair where it will be lowered into place. Portland stone is a limestone formed from the slow compaction of calcium carbonate and organic seafloor matter, like shell fragments, deposited during the late Jurassic period when the UK was situated in a more sub-tropical latitude. Dan Grimshaw is a design and construction specialist based in Bath and London. He is a mentor to the British Library’s prestigious Innovating for Growth programme and is a jury member for the BLT Built Design Awards.  For further information visit: www.beamdevelopment.co.uk

Steve Bennett, Managing Director, Dura Products The construction industry has taken a major step forward with Laing O’Rourke, the UK’s largest privately-owned construction company, announcing that it will only use low carbon concrete for all new projects. The change takes place with immediate effect, resulting in a significant reduction in the company’s scope 3 carbon emissions – that is the embodied carbon in purchased materials – equalling a carbon reduction of 28% compared to its concrete usage last year, a saving of 14.4 million kgCO2e. It’s certainly encouraging to see such a major player in our industry fully embrace a change that couldn’t be timelier. The Global Alliance for Buildings and Construction (GlobalABC) recently reported that the climate performance of the sector and the 2050 decarbonisation pathway is widening[1]. However, with the built environment generating 39% of annual global CO2 emissions, of course the industry needs to play a bigger role in mitigating them. Clearly, relying on designing and building developments that boast lower operational carbon – the energy needed to heat, cool and power them, which currently accounts for 28% of the estimated 40% of CO2 emissions emitted by the industry[2] – isn’t the full answer. Embodied carbon contributes 11% of the industry’s CO2 emissions – a smaller percentage than operational, but one just as vital to tackle if we, as an industry, are to achieve our sustainability goals. That’s because once it is locked into a completed building, it can never be recaptured. Architects and developers use Life Cycle Assessments (LCAs) that help to measure the embodied and operational environmental impacts of a project – from procurement, construction, operation and end-of-life – all to internationally accepted standards. They also allow project planners and designers to compare alternative materials and understand and evaluate which products and parts of the building have the most and least impact.  Importantly, LCAs offer major stakeholders a legitimate way to substantiate their environmental claims using credible data. Dura Products has long been a trailblazer when it comes to green construction – in addition to being predominantly created out of recycled plastic content, the products also require little energy use during transportation and installation thanks to their lightweight composition. They also provide the option to recycle again, as each unit can be reused, recycled or remade. Their environmental credentials were further underlined in September 2021, when we updated our first PAS2050 study and released our LCAs. Our flagship product, Durakerb, achieved a carbon footprint of 5.95kg of CO2 per 914mm unit. However, I stress that LCAs cannot account for the environmental savings gained from using building materials fabricated from waste products that would have otherwise gone into landfill: Durakerb is manufactured from 88% recycled material – from margarine tubs and used packaging, to post agricultural polymers and recycled car parts. The material composition of a solution itself is something too often overlooked, yet sustainable materials for infrastructure, such as drainage and kerb systems, could unlock the key for contractors looking to reduce the quantity of embodied carbon for clients – and future-proofing projects to ensure they comply with the increasing number of environmental prerequisites. I very much hope that with a construction company of Laing O’Rourke’s size making such a significant environmentally-positive move, this could be a catalyst for the whole industry to embrace more sustainable building products, and to take the extra steps and changes needed to embrace a more sustainable future. Building, Design & Construction Magazine | The Choice of Industry Professionals  [1] 2022 Global Status Report for Buildings and Construction | UNEP – UN Environment Programme [2] Embodied Carbon – World Green Building Council (worldgbc.org)