The UK project ... a cornice unit placed onto steel beam.
GRC fibres find new application
The high versatility and light weight of GRC – widely recognised in the region as seen through the many landmark projects where it is specified – has led to the development of a totally new concept in pole designs, writes BRIAN MARTEN of Saint-Gobain Vetrotex Cem-FIL.
01 March 2005
Glassfibre reinforced concrete (GRC), which has – since the early 70s – enhanced concrete’s portfolio of properties and widened its appeal to architects and engineers alike, continues to add dimensions to its versatility, among the latest developments being a totally new concept in utility pole designs.
The new concept in utility pole designs will have 15 to 18 per cent of continuous Cem-FIL fibre which is filament wound to form 7.5 to 15-m-long poles capable of sustaining roadside or sports field lighting or distribution or transmission line loads.
The versatility of Cem-FIL GRC has only just begun to be exploited.
Much of GRC’s appeal stems from its unique attributes. Whilst retaining concrete’s inherent properties such as a high compressive strength, non-combustible, durable surfaces, low maintenance etc, GRC factors in such advantages as a great reduction in weight and the ability to manufacture complex shapes.
This is made possible because Cem-FIL AR glass fibres, quite similar to steel -have high tensile strength and a Young’s modulus greater than concrete. This means that they can truly reinforce the basic concrete mix and, depending on the quantity used, can either modify regular concrete or produce the ultra-thin sections (12 to 20 mm), of low weight (25 to 40 kg/sq m) typical of GRC products, he explains.
This concept of making thin section concrete is demonstrated in Figure 1, which shows a 1.3 m capital unit made in the US. Once in place, it takes on the appearance of a solid sculptured stone or cast concrete (Figure 2).
A cornice unit made in the UK, is another example showing how thin GRC elements can be installed onto structural steel beams. In this case, the finish is an imitation stone, which has to match exactly other solid cast stone units on the same building. In such structures, GRC not only helps give sharp edge details to projects but also helps retain them.
“Such units would weigh one-fifth of the same unit in cast stone or precast concrete, allowing for significant savings in the structural steel work and foundations if specified at the design stage,” he points out.
The benefits of GRC have long been known and the material has been used extensively in the Middle East in several landmark projects for over 30 years. Nearly every country in the region has Cem-FIL GRC manufacturing capability, giving the client the opportunity to use locally manufactured materials. All GRC manufacturing companies have the technical capability and backing from the originators of GRC – Cem-FIL.
Completed projects where GRC has been used include Madinat Jumeirah and the Emirates Palace in the UAE, the Four Seasons Hotel in Doha, Le Royale in Amman and the Grand Mosque in Oman, to name but a few. Growth continues with GRC being already specified in many of the new prestigious projects such as The Palm, The Mall and The World in the UAE.
In Spain, Cem-FIL GRC’s lightweight and thin section was used to good effect in the renovation of the prestigious Palace Hotel in Madrid.
