Turning the screw on stud anchors
05 May 2015
In 2007, the construction market peaked at over €38 billion and employed almost 400,000 workers. One of the many consequences of this was the ‘build at any cost’ philosophy that grabbed the Irish market. The collapse that followed is well documented but, with the industry showing signs of improvement (output in 2014 rose to €11 billion and employment is back to approximately 110,000), there has been an important strategic shift in mindset, which is bringing key new technologies to the fore.
So the natural question is: why? There are fewer projects and tender prices have dropped substantially. As reported in the Society of Chartered Surveyors Ireland’s Construction Sector Outlook 2014: “Construction tender prices fell by 33% from peak, with tender prices now appearing to have stabilised and beginning to show an increase of around 3% per annum.”
So the emphasis has moved to build quickly, but with a critical focus on productively and safety – and to ultimately achieve these goals the market is looking at innovative tools and products.
Walk onto many sites now and the latest cordless battery tools, breakers, measuring lasers and direct fastening systems are more commonplace. Over the last 12 months, however, engineers’ attention has focused on a new area: screw anchors as a replacement for traditional stud anchors.“The specification of screw anchors is starting to gain momentum,” said Carlos Taborda, Northern Europe product manager (anchors) for Hilti. “This is because the technology has progressed to a point whereby the levels of performance are better, plus there are additional performance and productivity benefits which combine to make it more cost-effective.
“Roughly speaking, screw anchors accounted for approximately 13% of our anchor sales in Ireland in 2013,” he continued. “In 2014, that percentage rose to well over 20%, above which our market share has itself grown quite substantially. This equates to tens of thousands of extra screw anchors entering the market, and quarter one figures for 2015 indicate that both market share and screw anchor sales are set to grow further.”
One of the main reasons Taborda attributes to this rise in orders is the recently launched Hilti HUS3, its third generation of mechanical screw anchors. Raising the bar in terms of performance, the new anchor offers up to 30% higher design resistances than metal expansion anchors and supports loads equal or greater than stud anchors.
A unique design features cutting edges for easy settings, and no compromise in performance, even in hard aggregates, high-strength concrete and in contact with rebar.
HUS3 is also the world’s first screw anchor to feature a tested and approved adjustability process for quick and easy baseplate leveling, adjustments and realignments, without compromising load capacity. Peace of mind is provided by European Technical Approvals for use in cracked and non-cracked concrete and the product is also CE-marked.
The new design also means that the HUS3 anchors are fully removable and can be reused multiple times in temporary applications. A simple check using the HUS HRG tube provides a quick, convenient and approved test. Installers simply slide the used anchor into the specially designed tube – if it remains inside it can be re-used, if the anchor slips through it should be discarded.
Co Carlow-based Daniel Whelan Engineering Works is one of the product’s early advocates, having already used the product in two projects, with a third in the pipeline. “We installed glazed balcony railings in a new build apartment block in Dublin, which involved the installation of over 1,000 anchor points,” said Darran Hayes, design office manager. “We approached Hilti for assistance with the calculations and, at this meeting, the HUS3 was first mentioned and we were given a demonstration.
“Immediately the benefits were obvious, that being the speed of application. It was very easy to put in, but more importantly the flexibility to readjust. Traditional countersunk bolts offer no movement, when they are in they are in, and of course this can create problems,” Hayes continued. “The HUS3 worked brilliantly on the job, so much so that it’s a key consideration at the outset of any design. At present, we’re using it to mount further railing to a wall at a project in Newcastle, Dublin and over 1,000 more are to be ordered for a further project later this year. We’ll be using this product from hereon in, whenever applicable.”
Hayes was so impressed by the HUS3 that it invested in a Hilti fleet of power tools including battery and corded drills, cartridge tools, angle grinders, impact wrenches and others. This took the screw anchor from a standalone item to the complete Hilti system, which had further added benefits. “Not only do our operatives have to carry around less equipment, there’s a set method whereby each anchor installed is faster to fit and adjust, increasing productivity and decreasing the chance for any errors,” concluded Hayes.
Flexibility and ease of use
The flexibility and ease-of-use of the HUS3are not its only advantages. Within the manufacturing process, a new coating and optimised hardening process ensures robustness and protects against weathering. Anchors are available with hexagonal or countersunk heads, offering a neat appearance and meaning no further finishing is required.
Applications for HUS3 are varied, including safety-relevant fastenings in cracked and non-cracked concrete, static, quasi-static and seismic loading, railings and balustrades, steel beams and structural steel, facades and curtain walls, machines fastening and conveyors, racking, heavy mechanical installation systems, ventilation and air-conditioning and cable trays.
The Hilti SIW 22T-A Cordless impact wrench is the perfect match to drive the HUS3 screw anchor to its optimum depth and tightness. It also has space for installing a convenient holding bracket for the HUS HRG tube below the handle.
In addition, Hilti PROFIS Anchor software makes anchor selection safer and more reliable. Special design models allow the designer to find nationally and internationally approved solutions for a wide range of applications. Features include an interactive 3D interface and the exclusive Multiple Load Case Calculations to help the designer remove unnecessary steps and save valuable time. Download PROFIS for FREE here.
“The HUS3 is truly a revolution in anchor design and testament to the research and development capabilities of the company,” says Dennis Markey, marketing and operations manager, Hilti Ireland.
“With its easy-to-set, adjustable and re-usable characteristics, it’ll come to represent the ‘go-to’ anchor for a whole variety of jobs. Over the coming months and years, the popularity of the product will increase in the marketplace, and within the next few years we may even see screw anchors represent 50% of Hilti anchor sales in Ireland. This is, in no small terms, an achievable target.”
For more information and to watch the video, visit www.hilti.co.uk/hus3http://www.engineersjournal.ie/2015/05/05/turning-screw-stud-anchors/http://www.engineersjournal.ie/wp-content/uploads/2015/05/Hilti-Cover1.jpghttp://www.engineersjournal.ie/wp-content/uploads/2015/05/Hilti-Cover1-290x300.jpgSponsoredconstruction