More weather dismay heightens need for underpinning
Underpinning of foundations remains a likely prospect for buildings of all kinds in areas of the UK, following a month of stark contrast in terms of rainfall.
With heavy rains frequently forecasted by meteorologists, weather warnings for the whole country issued by the Met Office, and images of flooding making the news, you could be forgiven for thinking the deluges have been nationwide.
However, the Met Office has confirmed that, although June was the wettest on record in Wales and Northern Ireland, and for the UK as a whole, it was only the second-wettest in English history, and ranked just eighth on Scotland’s records list.
In certain parts of the north-west UK, it was actually one of the driest months since records began, with a few wet days at the end of the month just tipping the scales past the all-time lows seen by several weather stations.
Either way, it is these extremes of weather – rather than moderate and consistent levels of rainfall and sunshine – that can leave soil either waterlogged, and therefore less stable, or dried out and more prone to crumbling.
For properties in the worst-affected areas, it could be wise to check whether structural stability has held in this year of stark contrast, or whether underpinning methods may be needed to restore strength to foundations.
Nano-cement could make concrete piles intelligent
Concrete piles could, in the future, provide feedback about the condition of the ground around them, or the building that they support.
We have looked several times at how changing soil conditions can be bad news for pile foundations, as shifts in density and hidden underground cracks can affect their ability to bear a load.
However, engineering research at the University of Houston could soon make nano-cement – a cementitious substance that contains piezomaterials – a reality in the years to come.
The research is currently looking at options for using the material in the drilling of offshore oil wells, but the same principles could also be applied to concrete piles.
By adding nanoscale fragments of iron, calcium and silica to cement, it can be made to change electrically when it undergoes a change of temperature or is exposed to mechanical stress.
“It’s sort of like your skin – when someone touches your skin, you can feel it; you can feel the pressure,” says the developer, Cumaraswamy Vipulanandan.
By using this to provide feedback to the builders above, oil drills – and perhaps ultimately piling rigs too – can alert the workmen to any unusual conditions below, and allow construction to halt if a crack or leak occurs.
Concrete piles tap into Edison’s ingenuity
Concrete piles might not live up to Thomas Edison’s vision of a single-part concrete house, but they benefit from much of the same logic that went into his 1917 patent.
In that year, Edison patented a system by which seamless concrete dwellings could be created, using a mould the size of a house to contain the concrete until it set.
Several examples of this approach remain in the area around Edison’s factory at West Orange – and show how the US inventor was as focused on single-material construction as his avant-garde European counterparts around the same time.
Now, Matt Burgermaster, an assistant professor at the New Jersey Institute of Technology, is using similar principles to design and build ‘ice houses’, igloo-like structures with excellent sustainability credentials.
He calls Edison’s single-pour, moulded concrete concept “a forward-thinking approach to the integration of building design and construction” and a source of inspiration for “the creation of a more sustainable built environment”.
While concrete piles are just one component in a structure, they can have similarly beneficial sustainability credentials.
For instance, CFA piles can be poured into a drilled hole and reinforced once in place, before they set – creating a single-pour foundation with excellent strength, and with minimal disruption to the surrounding landscape and environment.
Badger-tracking technology could help see through concrete piles
Technology that was invented to track badgers could help provide GPS-like imaging in underground environments, including those built between concrete piles.
GPS is effective above the ground, but below the surface, materials like concrete piles used in foundations, along with rock and dense soil, can cause problems.
Now a team at the University of Oxford is working on a solution, using badger-tracking technology, which could help emergency services personnel locate people trapped underground in the future.
The system uses very low frequency fields and is effective at penetrating rock, soil and concrete even where there is a thick layer of the substance.
As such, it could be a useful way of seeing through pile foundations when people are trapped, or even simply to provide an indoor equivalent to GPS in public places like airports.
“The aim is to incorporate the new technology into smart mobile devices; a demonstrator on an Android platform is being developed,” the university reports on its science blog.
In the years to come, the innovation could help in emergency responses to major incidents, like the 2005 London bombings, in which victims in the affected London Underground stations were difficult to locate with existing technology.
Heavy-duty pile foundations can cope with industrial projects
A rapid rise in industrial construction project starts could have demand at a recent high for heavy-duty pile foundations capable of bearing substantial loads.
The latest figures from the Office for National Statistics show a significant growth in private industrial new work in the first quarter of 2012.
With the overall construction sector up by 4.6% over the previous three-month reporting period, private industrial contracts grew by more than ten times that amount.
The 57.9% increase in industrial work is likely to have seen heavy-duty pile foundations under renewed demand, while private commercial new work also rose by 27.8% over the same period.
In respect of the long term, new orders remain relatively subdued, but the ONS admits that the recent data form a “volatile series” with sizeable short-term changes.
When such volatility leads to rapid increases in orders in a specific segment of the sector, pile driving contractors are quick to respond in order to ensure that piling rigs are available where they are needed.
By providing piling rigs for industrial-scale projects, pile driving contractors not only help to keep these projects on track, but also ensure the industry as a whole can sustain any long-term growth.
Pile driving contractors can extend MPA’s safety support for SMEs
The Mineral Products Association (MPA) has been praised for its commitment to safety – a principle that pile driving contractors help to extend to construction sites when called in to lay concrete piles.
Foundation piling is a skilled process, and pile driving contractors are able to work on a site to lay concrete piles quickly, safely and effectively.
In addition, by hiring professionals to carry out foundation piling, building contractors are assured of a high-quality finish, and do not place any of their own construction workers at risk.
The whole process reflects the industry’s commitment to safety – something the MPA has just received a RoSPA award for.
RoSPA, the Royal Society for the Prevention of Accidents, granted its SME Assistance Trophy to the MPA in recognition of its ‘Safer by…’ schemes.
These include: Safer by Sharing, a series of regional seminars; Safer by Association, a tool for conducting site audits; Safer by Competence, an industry-wide commitment to competence; and Safer by Design, a voluntary guidance scheme for re-engineered and new mobile plant.
Martin Isles, director of health and safety at the MPA, says: “MPA’s membership is a ‘broad church’. As such, we strive hard to satisfy all members, particularly in the field of developing demonstrable personal competence.”
Continued extreme weather could make underpinning foundations a necessity
The British weather has swung back to being extremely dry and hot in the past few days – which could make underpinning foundations necessary to safeguard some structures.
Recent weeks prior to that have seen heavy rainfall take some areas out of drought conditions, while others languished under storm clouds and a hosepipe ban at the same time, following another heatwave towards the start of spring.
All this means soils have been expanding and contracting repeatedly over the early part of this year, as rainwater swells them and then the heat of the sun dries them out.
In some areas – particularly soils with root networks of trees passing through them – this is likely to have had a destabilising effect, which may put nearby buildings at risk.
Underpinning foundations can help by putting back much-needed stability in places where shifting soil or subsidence has changed the density of the surrounding land.
We can fit pile foundations and needle beams to existing properties, as a combined approach towards supporting the structure with minimal excavation work required.
Pile driving contractors could be in demand as new-start blip evens out
If you’re going to need the services of pile driving contractors in the next few months, it might be wise to make a booking sooner, rather than later.
The latest housing figures from Communities and Local Government show a drop in new project starts in the first quarter of 2012.
Between January and March, 24,140 new houses began construction, with the early stages of a project understandably the point at which piling rigs and pile driving contractors are most in demand.
This is an 11% fall over the previous quarter, and a 15% drop year-on-year.
However, the first quarter of 2011 had been unusually active, with 18% quarterly growth, while October-December 2011 also saw a quarterly increase in starts, taking market activity higher by 3%.
While it’s impossible to be certain, the latest report could just be a blip in a swiftly recovering market – and if the April-June quarter overcompensates, it’s likely that piling rigs and contractors alike will face renewed levels of demand.
Perhaps most tellingly of all, completions were up across the board by 6%, even when seasonal effects were taken into account – hinting that there is still life in the house construction market.
CFA piles can prepare public land for domestic builds
CFA piles could prove to be useful in helping the government achieve its ambition of building 100,000 homes on previously publicly owned land.
By 2015, the government wants to have enough land available on previously public sites to support more than 100,000 houses and flats.
Already it has managed to outline locations for 102,000 properties, on former army barracks, NHS hospital sites and coal yards.
However, building on brownfield sites that have not been used before for housing can be an unpredictable process, until the ground-bearing capacity of the land is known.
CFA piles help to overcome such uncertainty, as they can be put in place with very small amounts of noise and vibration, yet are able to support very high loads.
The Continuous Flight Auger approach is effective in confined areas where large excavations are not an option, which can be ideal if a brownfield site already has foundations in place from previous constructions.
Piling rigs simply bore a small hole into the ground, which is then filled with concrete and a reinforcing cage – a fairly easy procedure that means foundations can be put where you need them, without the whole site needing to be cleared of any previous developments.
The eco-credentials of concrete piles
Concrete piles can help construction companies to demonstrate their commitment to environmental issues, with clear benefits in terms of eco-friendly site practice.
On May 16th, Loughborough University is hosting an event at which several high-ranking individuals from concrete-related organisations will meet to discuss sustainability topics.
Ahead of the event, the Sustainable Concrete Forum has published figures showing how precast products including concrete piles are more eco-friendly than many people might think.
For instance, a quarter of the aggregates already used by the precast concrete industry are from recycled or secondary sources – and their end-products can often be fully recycled, too.
Precast concrete piles can be kind to other resources as well – with up to 85% of the water used by the industry reused or recycled each year.
Of the water that is used, more than a third (36%) comes not from the mains supply, but from licensed alternative sources – reducing the strain placed on the environment, and on drinking supplies, by the manufacture of concrete piles.
If you’re planning a project that needs to demonstrate environmental commitment from its outset, concrete pile foundations are one way to incorporate sustainability from the ground up.