The assessment of ground aggressivity and suitability of construction materials are fundamental aspects of geotechnics. Ground hosted sulfide and sulfate minerals are known to produce unwelcome implications for ground engineering. Confidence in selection of the most appropriate form of construction and mitigation methodology, must be based on the results of meaningful site-specific material characterisation and assessment of performance in the likely construction environment. It is apparent that many ground engineering practitioners do not fully appreciate that certain rocks and soils are liable to contain sulfur species that may negatively impact ground engineering projects. In practice assessment procedures are often followed without a clear understanding of the issues and how to best manage them. This approach is not always suitable for managing the extensive variability encountered in the UK. Furthermore, an appreciation of how the construction activities may bring about undesirable changes are necessary for design of appropriate mitigation and long-term management. This short article discusses some of the issues that may occur, particularly where pyrite is concerned and considers how these characteristics and associated risks may be managed.

Causes of construction groundwork damage brought about through physical deterioration of ground and engineering materials are attributed to a wide range of factors that involve physical, chemical, and biological processes. In the UK a high proportion of such occurrences in the engineering environment result from the presence of sulfate ions in groundwater, brought about through dissolution or reaction of sulfur compounds. Pyrite and gypsum are the most commonly occurring sulfur compounds likely to be encountered during construction works.  In certain locations, the source of the sulfate ions is clearly through dissolution of evaporitic deposits, but in many cases, covering a much wider geographical area, these are derived from the oxidation of iron sulfide minerals, particularly pyrite. Pyrite, and the other infrequent iron sulfide minerals are unstable in oxidising and damp atmospheric conditions typical of the construction environment and will rapidly weather, producing insoluble orange-brown hydrous iron oxide, with release of hydrogen (H⁺) and sulfate (SO₄^2-) ions into solution as mobile sulfuric acid. This has a significant negative impact for ground engineering when reaction occurs consequent of ground disturbance, creating conditions that are aggressive to ground material including buried steel and concrete and, in some cases, raising sulfate to harmful levels.

Reaction of the sulfuric acid with other calcareous minerals such as calcite or concrete, give rise to selenite-gypsum as discrete crystals, and this involves expansion. The replacement of pyrite and calcite by selenite involves a volume increase of around 103%, developing ground stresses and causing differential heave due to indiscriminate crystal growth. This chemical alteration is frequently accompanied by rapid deterioration in engineering properties of the host material and the volumetric gain often causes disturbance in filled ground, and failures of foundations, earthworks, underground excavations, tunnels, and slopes. Observations have also documented abiotic pyrite oxidation where the pH of pore fluids was around pH >12, indicating that this reaction mechanism can also occur when pyrite bearing ground is treated using lime and cement.

The oxidation of pyrite is complex, it occurs through various reaction stages, at different rates, which conclude in a range of products. Ultimately reaction depends on various aspects including the crystalline form and grain size of the pyrite, the mineralogy and fabric of the host, and environmental conditions, including the exposure to weathering brought about by the engineering work. To manage any negative impacts to design and construction, the possibility of changes promoting the potential for pyrite oxidation during and after construction needs to be considered.

Sulfur is an abundant element in the Earth’s crust and occurs in geological materials of all ages and origins, in a variety of forms. Sulfur is highly reactive and readily combines with most non-noble elements, particularly under reducing conditions, to form metallic sulfides of which the iron form, pyrite (FeS₂) is the most widely occurring, along with its less common dimorph marcasite (FeS₂), and occasional pyrrhotite (Fe_1-xS where x = 0 – 0.2). Gypsum tends to be the most widely occurring sulfate mineral and is frequently encountered during ground works. Gypsum occurs as a primary accumulation in evaporite deposits such as the Mercia Mudstone Group and forms through evaporation of saline waterbodies. But it is more widely occurring as the crystalline ‘selenite’ form, which tends to develop as a ‘secondary’ product of contemporary weathering action on pyrite in the presence of calcite. The oxidation of pyrite will also give rise to high concentrations of sulfate ions which are mobilised by groundwater. Not all forms of sulfur are troublesome in engineering situations, although this depends upon the environmental conditions. Some recalcitrant mineral sulfates, such as barytes, celestine, and organic sulfur are relatively stable in weathering environments, and do not contribute to the sulfur present in groundwaters, unless conditions are unusual, so they are unlikely to impact significantly in construction and geo-material applications. Therefore, knowledge of the likely occurrence and attributes may help to manage potentially adverse conditions that could occur during and after construction.

Pyrite is remarkably widespread in its occurrence and is found as a minor constituent in a wide range of naturally occurring materials. It occurs in rocks and engineering soils, ranging from ancient sediments to Recent deposits, igneous and metamorphic rocks and hydrothermally deposited mineral veins. Pyrite occurs as diverse forms including variously shaped grains, nodules, and well-formed crystals, ranging from microscopic to several cm across; the morphology of pyrite has an influence on its potential for atmospheric oxidation. Therefore, its appraisal may help to determine its potential reactivity and the suitability of pyrite bearing ground and geomaterials for particular applications.

The different forms of pyrite and their combinations all share the same internal arrangement of iron and sulfur atoms but conditions during formation affect the crystal form. Well-crystallised pyrite occurs in the brass-yellow macroscopic form as large masses, veins or as large discrete often striated cubic, octahedral or pyritohedral crystals a few millimetres to a few centimetres in dimension and are commonly referred to as the ’non-reactive’ form of pyrite.  Typically, these are found in rocks that are well indurated and / or have been subjected to moderate to high-temperatures and pressures.  These well-crystallised forms of pyrite have a densely packed structure and relatively small specific surface area such that they tend to respond slowly in weathering environments. Macroscopic forms of pyrite occur extensively in igneous and metamorphic rocks and some hard-rock limestones, sometimes in substantial concentrations distributed through the host and tend to be relatively stable in construction environments.  These deposits are widely worked in the UK for construction aggregates in which slow oxidation or combination with cementitious binders may lead to problematic chemical reactions. In less-well indurated sedimentary rocks, pyrite may occur as visible nodules or smooth faced crystals, but more typically, it takes the form of disseminated microscopic framboids that are very difficult to recognise.

The microscopic framboidal form of pyrite is of greatest concern to ground engineering. Framboidal pyrite tends to form in sedimentary environments under anoxic reducing conditions through microbial activity where it remains stable, but when exposed to oxidising and damp atmospheric conditions it may rapidly deteriorate with consequentially detrimental effects.  It is commonly found in dark coloured (grey and dark grey), fine-grained sedimentary deposits including clays, mudstones, argillaceous limestones, siltstones, sandstones, and low-temperature hydrothermal deposits. The microscopic reactive forms of pyrite may also occur in newly formed sediments, including marine sands and gravels and river flood plain deposits, which are widely used as construction aggregates. Framboids are raspberry-like spherules, typically 2 – 80 μm diameter, comprising of ordered agglomerations of microcrystalline pyrite grains that are themselves <0.3 – 2 μm in diameter. They occur as disseminated spherules, clusters, or dark greenish-grey coloured concentrations along partings. The framboidal structure results in grains with a large surface area in proportion to their volume, making them highly susceptible to oxidation in an oxygen and water bearing atmosphere and oxygenated water.  This reaction may be mediated and greatly accelerated by microbial intervention from bacteria such as the ubiquitous Acidithiobacillus sp., which rely on electron transfer between Fe²⁺/Fe³⁺ for their metabolic process and this functions as a key mechanism in the oxidation reaction. In the ground engineering discipline, this form of pyrite is often referred to as the ‘reactive’ form of pyrite.

It is cautioned that the allusion to the visible form of pyrite as ‘non-reactive’ is not strictly true, the well-crystalline macroscopic forms of pyrite are still susceptible to oxidation following exposure, but depending on their surface condition, reaction generally will occur over a much slower timescale and may not be considered significant where construction is concerned, although it may be expedited where physical damage occurs to the crystals and through reaction of less stable forms. Therefore, potential reactivity must be assessed, with judgement also relying on previous experience of that material.

In the UK, framboidal pyrite is widely found in the dark coloured deposits of marine and fluvial origins of Carboniferous, Jurassic, Cretaceous and Eocene age. These account for a large part of the near-surface stratigraphy that contains many major urban centres. Through weathering, sulfate minerals can be present at shallow depth, whereas sulfide minerals may predominate at greater depths where oxidation has not occurred. Weathering involves physical and chemical changes to the natural material as it adjusts to different overburden pressures and the presence of atmospheric gases.  The change in pressure results in development of fissures and joints which facilitate the movement of oxygenated groundwaters. Water movement promotes chemical adjustments including hydration, dissolution and alteration of certain minerals and the formation of other minerals.  The distribution of sulfate varies within the weathered zone, with the top few metres having negligible amounts due to removal by rain leaching, but elevated levels may be present at the base of the root zone at around 2 to 3 metres depth, decreasing towards the base of the weathered zone, and this is identified by presence of brown staining on fissure and bedding surfaces, and presence of selenite. The weathering state is revealed by the colour changes of the iron forms present. In weathered horizons, the orange-brown colour of ferric iron predominates, whereas with depth the grey colour of ferrous iron represents less weathered lithology and indicates an increase in the presence of unreacted sulfide minerals.

Although British, European, and other standards promote good practice in carrying out investigations, potential problems are often not adequately anticipated and catered for. Historically the Building Research Establishment have provided guidance for routine UK assessment of potential ground aggressivity based upon water and acid soluble sulfate content and acidity of soil and groundwater samples. This worked well for many decades with few instances of sulfate attack on buried concrete reported.  However, following investigation on several cases of sulfate attack on construction materials and disruptive ground heave during the 1980s-1990’s, it was realised that the consequences of pyrite oxidation were not being considered and had been attributed to various other assumptions. Precipitation of new minerals such as gypsum provoke possibilities of ground heave. As the process of dissolution and precipitation will not generally occur in the same location, both expansion and void creation may produce differential movements and heave causing structural damage. This necessitated revision of testing standards, and guidance advocating a staged approach based on initial review of the geological setting, followed by a planned investigation programme and detailed ground assessment. This requires an awareness of potentially aggressive material and importance of focused chemical testing. The severity of pyrite oxidation depends not only on the crystal form but also on the permeability and chemistry of the host deposits as well as the groundwater conditions. The site investigation may confirm the presence of significant quantities of pyrite, gypsum, and calcite but these values alone do not facilitate assessments of the reaction rate and significance to construction. Assessment also requires that the consequences of the construction activity and weather-related issues in the construction period and beyond are fully addressed to provide an adequate basis for the design of structures.

The consequences of pyrite reaction may become a significant hit for the construction budget and progress when unsuspected. The oxidation of pyrite bearing deposits during earthworks and construction has been observed to progress rapidly over a matter of weeks or months, producing conditions chemically aggressive to engineering materials. Therefore, to avoid or manage potential problems attributed to pyrite oxidation it is necessary to know not just that it is present, but also its distribution, its form and reactivity. Investigations and construction may overlook the potential for material deterioration, but this can be determined at a site level through observation of changes following exposure and targeted chemical testing. The distribution of sulfur compounds in soils and rocks can be highly variable so testing must ensure that sulfur-bearing horizons are not missed, and a suitable characteristic value selected for design. Material selected for laboratory testing should focus on the construction zone but also evaluate other strata that may be affected.

Knowledge of the mechanical behaviour of the host material and the changes brought about through exposure during construction may expedite management of the construction process by facilitating re-use of a favourably weathered product that would otherwise constitute an unsuitable material. Ultimately, management of material avoiding costly offsite disposal, may be achieved through informed investigation with pre-weathering of pyritic fill to mitigate the risk of heave through conversion of pyrite to selenite or by blending, encapsulation, or provision of targeted drainage and impermeable barriers.

Article provided by Mourice A. Czerewko, Associate Engineering Geologist, AECOM Ltd

On 20^th September 2023, the AGS held a webinar entitled Second Generation Eurocode EN 1997: Where are We and Where are We Going?. The webinar was chaired by Chris Raison (Director at Raison Foster Associates) and included presentations from Dr Andrew Bond (Director at Geocentrix), Matthew Baldwin (Independent Consultant) and Stuart Hardy (Technical Leader – Geotechnical at Laing O’Rourke).

The webinar was split into two parts, the first part which was presented by Andrew Bond focused on preparing for the Second Generation Eurocodes and gave a clear timeline for publication. Andrew also provided information about Second Generation Eurocode EN 1997: Geotechnical design – Part 1: General Rules.

In the second half of the webinar, Matthew Baldwin presented on Second Generation Eurocode EN 1997: Geotechnical design – Part 2: Ground Properties, explaining the changed content and layout of this part of the standard.

Stuart Hardy provided an overview of Second Generation Eurocode EN 1997: Geotechnical design – Part 3: Geotechnical Structures and covered the changes which have been made to the clauses and what has not changed from current UK practice.

If you missed the webinar, the recording is now live on the AGS website and is free for AGS members and £30 for non-members (Ex. VAT).

Full Name: Bradley Falcus

Job Title: Senior Geo-Environmental Administrator

Company: Central Alliance Pre-Construction Services Ltd

I’m an early career professional who believes that the power of people can never be underestimated, nor should it be underappreciated. Over the past four years since my masters degree, I have become experienced in the geotechnical sector working in archaeology, geophysical exploration and ground engineering. I have quickly adapted to a management role within this timeframe, developing a team of trained geo-environmental and business administrators before the age of 30. I am passionate and driven to make a difference in the geotechnical sector, be that business-by-business, or wider reaching to the AGS’ members.

Are there any projects which you’re particularly proud to have been a part of?

I suppose my answer to this is split into two, one for my role within Central Alliance and one for my role within RSK. Working as one of the Data Managers on the Wales and Western Framework (Network Rail) has been a fantastic opportunity for me to learn and develop. The role is multifaceted and requires a great attention to detail and seems to continue to grow arms and legs with every week that passes. I enjoy working with my colleagues at Central Alliance on framework projects like this, it gives me the opportunity to work closer with them as part of the project management team and share in the delivery of great results to our client.

Within the wider RSK Group, I am a co-chair of the RSK Pride Network, an employee ran network which supports and welcomes LGBTQ+ people in the workplace. In July 2023, RSK were one of the sponsors of Bristol Pride. We brought together staff members from across the UK and had a wonderful celebration of our RSK Family. I can honestly say it has been an amazing event to organise and run – hopefully we’ll have more like it in the future and maybe we can extend the invite to other AGS members.

What are the most challenging aspects of your role?

Time! I think with a role like mine, it’s quite easy to forget when to switch off. Some days it will be nine hours of meetings, some days it will be nine hours of tender compilations, some days it will be nine hours providing training. Every day is different from the one before it; and even though that makes it interesting, it can be overwhelming if you don’t have the right procedures in place. Best advice from me is to make sure you take time for yourself, in and out of your work hours – don’t be a martyr to Ground Investigation by slaving away for hours and hours.

You have recently joined the AGS Business Practice WG to help develop Equity, Equality, Diversity and Inclusion within the AGS. What are your aspirations for the AGS?

Two of the UN Sustainable Development Goals are Gender Equality and Reducing Inequalities; these are targets that we as an industry have to take seriously going forward. I believe that trade associations like the AGS have a fundamental role to play in changing the attitudes of businesses across the UK and internationally on how we can be more equal and inclusive. I really do have aspirations that the AGS will be able to champion employment equality and equity, increase graduate opportunities and to represent the underrepresented. I hope that we can, as the BPWG, spark conversations around the topic of reducing inequalities across our industry and continue to welcome generations of new bright minds to the fold.

What do you enjoy most about being an AGS Member?

I love being able to connect with so many intelligent and interesting people that are part of the AGS. It’s inspiring as a young professional (I think I qualify for that title) to attend conferences and webinars to learn from the vast amount of experience there is in the group. Personally, I cannot wait for the next in-person meeting and hope to see many friendly faces there.

What do you find beneficial about being an AGS Member?

Being able to keep on the pulse of all the updates from the geotechnical and geoenvironmental sector – rules, regulations, guidance and procedure change so quickly, it’s always good to be part of the movement than behind it. Also being able to interact with the different working groups is invaluable, by attending conferences and meetings you have the opportunity to shape the future of the geotechnical industry.

Why do you feel the AGS is important to the industry?

The AGS is one of the best platforms for collaboration in our industry –  Helen Keller, an activist for disabled rights, said that ‘Alone we can do so little, together we can do so much’ and I think about that quote quite a lot and what it means for us. It’s important to know that we aren’t as secular or ‘alone’ as we sometimes believe to be. The AGS is a shining example of fantastic minds, creative people and keen advocates coming together for the future of our sector.

What changes would you like to see implemented in the geotechnical industry?

In my dreams? I would love to have collaborative networks created between AGS member businesses which minority communities (for example: POC, LGBTQ+, people who are neurodivergent, people who are disabled, etc) would be invited to join. These networks could have regular meetings, chaired by the AGS, where they would be able to give direct feedback and guidance on what the industry can improve upon. I’d hope we could create a welcoming space for all people to join us from all backgrounds and ensure that their voices are heard. In the meantime, I would love to see guidance from the BPWG on tackling unconscious bias and good hiring practices in our industry as a fundamental step in the right direction.

Name: Tim Clegg

Job title: Managing Director

Company name: Geosense Ltd

What does the company do and what areas does it specialise in?

Geosense is a leading UK manufacturer and global supplier of Geotechnical Instruments and data acquisition systems. We specialise in the design and manufacture of MEMS and Vibrating Wire monitoring sensors which are used in many sectors including site investigation, dams, bridge, deep excavations, infrastructure, mining and more.

Where is Geosense located?

We have a purpose-built manufacturing facility in Suffolk.

How many people does the company employ?

Currently 59. Interestingly, three years ago it was around half that, but we have needed to grow to meet the rising demand for our products. We recruit mainly from the local area, with many of our staff joining us as school levers and working their way through the business to hold managerial roles. Since Covid, we have also been able to expand some roles to fully remote working with two members of the sales team based in Manchester and a member of technical support near Oxford. We have also recently employed our first overseas employee in the US.

How long have you worked at Geosense?

I worked part time during school holidays from the age of 16. My full-time role at Geosense started in 2013 so I would say I have been at Geosense 10 years. Time does fly!

What is your career background, and what enticed you to work for Geosense?

My career background is short! I started as a pot washer at a local pub and worked at a local supermarket before heading off to the University of East Anglia in Norwich. I studied Economics for 3 years before joining Geosense assisting in the production department.

Geosense is a family business but working at Geosense was not always a route I wanted to go down, nor one which was expected. However, I can say I love my job and consider myself lucky to have the opportunity to work in this industry.

Knowing what I know now, the best part of working at Geosense is the exciting projects we work on, and the people we work with. This industry is full of passionate people who genuinely care about the work we do and the value we provide on every project.

What is your current role within Geosense and what does a typical day entail?

I am currently Managing Director. A typical day? I am incredibly lucky that I get to work across multiple departments all performing important functions in the business. Officially my role is to ensure everyone is happy and to make decisions on current and future strategy. Unofficially I do anything that is required on any given day.  In short, I get to work with a great team to make some very exciting stuff happen.

This week I have been working with our software developer on an exciting new development digitising our calibration data. I was also looking at new types of sustainable packaging and had a 6am call with Singapore and a trip to the Houses of Parliament. As I said, quite varied!

Having been Commercial Manager, Sales and Customer relationships is what I know and I help a great team who look after our customers across the globe. Customer care and support is key to every member of the Geosense team.

What are the company’s core values?

We recently did a workshop with the whole company to put forward and agree on our companies values as we enter into an exciting period of growth in the company. The company has grown significantly, and we wanted to develop new values that could help us navigate the future whilst recognising what made us successful. We chose the following:

Open & Honest Communication

Care & Respect

Collective Responsibility

Client Focused

Agile

These values embody what Geosense is and how we want to work, they were decided and agreed by every single member of staff.

Are there any projects or achievements which Geosense are particularly proud to have been a part of?

In 2022 Geosense was one of 141 companies in the UK to win a Queens Award for Enterprise for International Trade. Seen as the most prestigious award a UK company can receive, we are particularly proud that the certificate was one of the last to be signed by the late Queen Elizabeth II. The main thing is that it recognised the hard work and skill of every single member of the company, past and present, during the last three years.

As for projects, we are proud to have been involved in many well-known UK projects such as Tower Bridge, Tideway, HS2, Battersea Power Station, HARP and Woodsmith Mine, to name but a few.

I am hugely proud when I walk around London and know that our sensors have helped monitor some of the capital’s most iconic structure. Often very frustrating for friends and family who join me scouring buildings for the total station or dataloggers!

How important is sustainability within the company?

As a responsible modern business, we have sustainability in mind on what we do right now and our plans moving forward. Our production facility is heated/cooled using ground source geothermal and our roof is full of solar panels.

We have an internal environmental committee, with members from all areas of the business discussing and creating our vision to have as small as possible negative impact on the planet. We are also currently implementing a roadmap to zero plastic packaging for all products.

Recently we digitised all our calibration data which means that we will be phasing out paper calibration records in favour of QR code-driven digital records. If clients do want paper copies, we will be donating £1 for every paper copy to Forestry England.

We are a proud UK manufacturer and, where possible, keep the majority of our supply chain within the local area and the UK. We firmly believe in managing a sustainable supply chain.

How does Geosense support graduates and early career professionals who are entering the industry?

We are big advocates of training and personal development for our staff. A number of the team are completing formal qualifications as part of their roles at Geosense.

Geosense has always been proactive in providing training and support for engineers. Recently we launched our Geosense Academy which provides tailored training on our products/applications to a wide range of professionals, including graduates and early career professionals. To date over 80 engineers have been through the academy.

We are always open to summer placements for graduates if they want to learn more about the industry or manufacturing.

How has COVID-19 impacted Geosense today? Are there any policies which were made during the pandemic that have been kept to improve employee wellbeing and productivity?

I think the main impact that should be addressed is the affect that COVID had on everyone’s wellbeing. I am very glad that this is now something that is being discussed more and businesses are taking a more active role in managing wellbeing. At Geosense, we have increased the number of mental health first aiders to 5, and also offer an EAP system to offer support to staff. We are also providing food in the canteen to help ease some of the burden of the cost of living for our staff.

Flexible working was already being implemented but COVID certainly sped things up for us! Since COVID we have continued with flexible working and have also introduced flexible working patterns for production which has been really well received.

One small thing we introduced in the sales team was a Monday morning meeting where the first section of the meeting was to go through what everyone did at the weekend, with a Friday meeting to share what the plans were for the weekend. This made the meetings not just about business and made a huge difference during COVID. At least the things we do at the weekend now are a lot more exciting than they were during COVID!!

Why do you feel the AGS is important to the industry?

I must admit I used to think the AGS was mainly centred around data format.

However, having attended many conferences and being involved in the AGS I&M working group, I have seen a large group of passionate professionals who want to help standardise the industry and make the use of Geotechnical methods as easy and useful as possible. Also, while a lot of our work is construction aligned, we often get ‘lost’ within the construction industry bodies. The AGS fulfils an important role for the sharing of ideas and discussing how best to pass this information to different parts of the wider industry,

I now see the AGS as a group who want things done properly in our industry!

What are Geosense’s future ambitions?

To grow while still enjoying the journey!

Our industry is experiencing an exciting period with great innovation and increased adoption. We are at a point we can shape and point the industry in a good direction.

With greater connectivity options, digital innovations, and the ability to do more with data the future is very bright indeed.

The UK’s leading construction show returns to Olympia London’s Grand Hall on November 15th & 16th.

London Build offers thousands of unique experiences over the two days with 500+ incredible speakers across 8 stages, 350+ exhibitors, Meet the Buyers, live product demos, networking parties, entertainment, live music, the UK’s biggest Festival of Construction and endless networking opportunities with leading architects, developers, housebuilders, contractors, government and more.

Featuring:

• 35,000+ registered visitorsfrom contractors, architects, civil engineers, developers, local councils, house builders/associations and construction professionals
• 500+ inspiring speakersacross 8 conference stages including Future of Construction, BIM & Digital, Fire Safety, Sustainability, Diversity & Inclusion and more
• 200+ hours of CPDtraining and education
• The UK’s biggest Festival of Constructionwith DJs, musicians, live performances, celebrity guests, entertainment and competitions
• Meet the Buyers with Procurement Teams exhibiting from Balfour Beatty, Skanska, Mace Dragados, BAM UK, Costain, SMP Alliance and more
• Architect’s Hub with project displays and 3D models of upcoming projects from leading architects across the UK
• The latest insightsand updates on major upcoming construction projects and opportunities across the UK
• Exclusive networking eventsco-hosted with Urbano Build, London Constructing Excellence Club, Forum for the Built Environment, The CIOB, Building People, Let’s Build, Building Equality and many more
• The UK’s largest networking events for Women in Constructionand Diversity in Construction
• An inclusiveAmbassador Programme supporting Women in Construction, Diversity in Construction and Mental Health in Construction
• 350+ exhibitors showcasing the latest services, products and innovations transforming the industry

Register for tickets at www.londonbuildexpo.com/