Last year New Civil Engineer surveyed 1,300 engineers to establish levels of knowledge around the design, selection and installation of fixings.
Confidence levels of contractors and consultants in anchor installation were inconsistent with 34% of consultants and designers, and 12% of contractors and sub-contractors not confident that chemically secured fixings are properly installed on sites.
The survey also found that levels of awareness about the code of practice for the selection and installation of anchors in concrete and masonry, were also surprisingly low – 38% of those surveyed said they had not heard of the standard while only 28% said they were “not sure” if they were aware of the standard.
At at recent round table debate in association with Hilti, engineers, designers and contractors discussed the underlying issues with concrete fixings and how the industry could ensure the design, selection and installation of anchor fixings stay safe.
“It’s a constant battle with gravity,” argued Balfour Beatty tunnelling manager Roger Bridge, “And what we expect these fixings to do.
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“We hear about the projects that have had failings, but for me it is further down the supply chain where people don’t understand the fixings and how structures perform. And how the interactions with the fixings can potentially be castastrophic.”
Steve Denton, head of bridges and ground engineering at WSP Parsons Brinckerhoff is involved in a research project around the issue. He explained that there was work at the design stage of a project to make future management easier. “There are decisions you can take at the design stage that give you the ability to test things later, or by choosing the way to install something to increase the robustness of an asset.”
The research project, which is being managed by Highways England, is concerned about the risk associated with the concrete fixings it already has installed, and asking if existing design and installation guidance is adequate.
“The strong feedback that we got was that there is a very high degree of confidence in the quality of the guidance, but the concern was about its application,” added Denton.
So do we need to make sure that the safety critical nature of installation is properly communicated?
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Trained competent installers of safety-critical fixings are needed, argued Costain chief engineer Calvin Blacker. “Other areas of the industry have qualifed installers, we need this for fixings too.”
Bridge agreed, but added that the work is “repetitive” and that supervision would be critical. “Relying on that person to put the concrete fixings in right would be superfluous if the supervision was good enough.”
David Dunne, a principal engineer at Aecom thought site workers should be given more credit and that blame should not be passed down the supply chain. “We should be explaining why the work needs doing and in that way so they understand the reason as opposed to doing something for the sake of it.”
“And that there should be more education around materials in general, not just concrete fixings” added Dunne.
Robots could be the answer, given the repetitive nature of the work, suggested WSP Parsons Brinckerhoff technical director Audrey McIver. Bridge thought so too. “You give a guy a drill and tell him to drill a thousand holes, he is going to lose the will to live. You train him to operate a robot, you have elevated his status and he takes pride in what he does.”
Blacker thought it was a shame that the skills were not certified and workers have to complete the training again when moving from project to project.
Hilti has been investigating possible certification. Its head of engineering Kirsty Walton explained that in Germany certain roles on site had been certified so those carrying them out could be offered a certified course. “There are things from different markets that we would like to implement here. Working with the Construction Fixings Association (CFA) we are looking to see if we could offer anchor installer training,” she said.
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Walton added that different manufactors’ fixings have different installation methods, but there was scope to offer training via a third party so certification could be taken from site to site. “Rather than having something relevant for one Hilti fixing, let’s have something that says you understand how to install all fixings,” she urged.
Empowering the workforce
So if empowering the workforce is beneficial, how can we make sure that installation is completed to the required standard? Denton argued that when dealing with risk, there were multiple ways of mitigating it.
“If risk can be resolved at design stage that’s great. If not, then you want competent people all the way along the chain – a compentent designer to a compentent installer. Having one does not negate the other.”
“If people actually read the British Standard, then would many of these issues actually go away?” asked Denton. He felt that standards were often criticised for being prescriptive, while others criticised them for being too flexible.
“You need to write standards that enable the competent designer to be able to apply them safely. But you don’t want to inhibit the expert.”
Arup director David Caiden thought that safety could be improved by considering the use of each type of fixing and being aware of the circumstances and consequences of a possible failure.
“The consequences of failure may or may not be severe, and need to considered in the design. If one fixing fails, then it is threatening the others. This is now standard practice, whereas probably 20 years ago it wasn’t.”
Hilti’s Walton agreed, adding: “Again it is making it clear at site level to the installer why you are asking for one more fixing than they might expect.”
Costain’s Blacker said he thought the installer’s skills should be recognised. “If installers were given a bit of self worth, they would be be proud to say that they installed a certain anchor on a certain day.
This could improve safety too. “At the moment if we do have some failings – we don’t know who installed which anchor, which gang, where else they have been installing.”
So do clients have the appetite to invest in improving safety? WSP Parsons Brinckerhoff’s Denton used the example of a research project looking at the risk associated with installed concrete fixings and existing guidance.
“It’s clear they have. Major infrastrcture clients have come together and invested in this work to design new fixings to enable better future management.”
But it’s the sharing of knowledge across the whole industry that needs to be improved thought Hilti’s Walton, speaking on behalf of the whole fixings industry. “We want to put the safest products on the market but we need input from the profession so we can up our game and keep it up.”
Round the table
Calvin Blacker, chief engineer, Costain
Roger Bridge, tunnelling manager, Balfour Beatty
David Caiden, director, Arup
Matthew Cook, director, Building Design Consultants
Steve Denton, head of bridges and ground engineering, WSP Parsons Brinckerhoff
David Dunne, principal engineer, AECOM
Mark Hansford, editor, New Civil Engineer
Audrey McIver, technical director, WSP Parsons Brinckerhoff
Ponciano Perez Lupi, project manager, Ferrovial Agroman
Alan Skarda, section engineer, Kier
Katherine Smale, technical reporter, New Civil Engineer
Kirsty Walton, head of engineering, Hilti
In association with
Hilti logo cmyk 2014