Construction piling prepares for another wet weekend
If your plans for the weekend have been hampered by severe weather warnings, spare a thought for construction piling work that had been scheduled to take place over the past few weeks.
At a time of year that is usually warm and dry, we have had unprecedented levels of rainfall in short bursts, and it’s likely to rank among the wettest summers on record by the end of the season.
For construction piling works, that means a flexible approach is required, to avoid pouring liquid concrete into waterlogged ground.
One option is to use pre-cast concrete and steel piles, with professional piling equipment to drive these deep into the earth.
By using pre-cast piles that have been set in controlled conditions, away from extremes of the elements, you can avoid unnecessary extra pile testing once they are in place.
Instead, standard pile testing should be enough to ensure that your foundations are solid – even if the soil around them is a little soggier than usual.
And in places where the ground has been permanently affected by the recent soaking, underpinning methods can restore essential strength to structures.
With further rain warnings in place across the south of England and as far north as the Humber, we’re ready to offer our underpinning methods wherever they’re needed in the days and weeks to come.
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.
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.
Precautions help Olympic Park pile foundations to be laid without risk
The pile foundations that will support stadiums on the Olympic Park in London this summer were laid with safety firmly in mind.
A report from the Health and Safety Executive and the Olympic Delivery Authority notes how the pile foundations were subject to safety assessments – in particular, attempts to determine how loud the work would be.
Planners then used a ‘bullseye’ method to create red, amber and green zones around any location where piling rigs would be used.
Those working on the piling rigs were required to wear ear defenders, while those further away had the choice over whether they wanted to wear them.
In the green zone, furthest from the piling rigs, no ear protection was necessary – and quieter work could continue uninterrupted.
The project is a great example of how foundation piling can take place even on a site where other work is being carried out, and how professionals can make sure no workers are put at unnecessary risk by doing so.
With all eyes turning to London this summer, it’s good to know that the Olympic venues are built on firm foundations – and that they were laid with safety in mind.
Concrete piles make use of essential, economy-boosting materials
Concrete piles not only help to support your structure – they can also support the economy, according to a new government publication.
The National Planning Policy Framework has been compiled to address three concerns: sustainable economic growth; environmental protection; and complexity in the planning system.
It sets out plans to ensure quarried materials such as aggregates and concretes remain available for a long time to come, while noting that they are a finite resource.
But it also recognises the contribution towards economic growth that materials such as concrete can make.
Concrete piles have long been among the most frequently used methods of supporting new structures, but this may be the first time many people have become aware of their economic value.
“It is heartening to see recognition of the need for essential minerals as a strategic issue, both nationally and locally, and the great weight that needs to be given to the benefits of mineral extraction, including to the economy,” says Nigel Jackson, chief executive of the Mineral Products Association.
The NPPF calls for local policies to be created to safeguard the future supply of essential minerals, but adds that existing concrete batching facilities should be protected along with existing, planned and potential production sites for other concrete products.
Concrete piles are cancer-free
Concrete piles are still a strong support for any structure, despite recent reports to the contrary.
The Hammersmith Flyover was closed in late December 2011, due to structural concerns, leading to reports of ‘concrete cancer’ in its supports.
But the Mineral Products Association has pointed out that the problem was not in the concrete itself, but in the internal steel cables of the flyover.
These had corroded due to saltwater – which, in turn, had been created through gritting the road, instead of heating it from beneath as originally intended.
“It is regrettable that concrete, which is such an essential material for both existing and future infrastructure, has been misrepresented in such tabloid terms,” says MPA chief executive Nigel Jackson.
The story highlights the importance of understanding the materials used, in order to keep them in good condition for the long term.
However, it is also important to recognise that the problem was not as reported by some parts of the press – and concrete piles are still a strong and reliable option.
With pre-cast concrete piles available to bring in from off-site, construction projects can continue at a good pace, while ensuring the most important parts of the finished structure are made to a high standard by specialists.
Making use of Concrete Piles
Concrete piles are one of the most common types of piling. They are often used on construction jobs taking place on houses as well as other buildings, meaning that they have a wide range of use.
There are quite a few advantages to using concrete piles, which is one of the reasons they are used so often. For instance, they have a long track record of success that makes them ideal for underpinning foundations. They can also be used straight after being installed and, as they are relatively fast to install compared to some other methods, they make a good option when time is of the essence.
Concrete pilings are designed to last as long as the concrete foundation itself, meaning that they have a long service life. To install them, they are pushed under a foundation into the ground, effectively underpinning the foundation to give it extra support. They are installed by digging a hole next to the foundation, which will normally end around two feet below the bottom of the foundation.
Then the cylinder is placed into the hole and kept in place by using a ram. This process is completed until the space has been filled. Once they have been installed and signed off on, any other work that was going on at the property can continue.