Glass Fibre Reinforced Concrete
GRC – Cementing its place in the Australian architectural landscape
By Kathleen Aoki
Glass Fibre Reinforced Concrete, or GRC, has long been recognized as an exceptional building material due to its vast design flexibility and light weight. But the number of GRC building projects in Australia has lagged behind other parts of the world where GRC has established itself as a viable and cost-effective building material.
However, a recent resurgence of interest in GRC is bringing this promising material back into the spotlight, as several large-scale projects throughout Australia can attest, including the high-profile renovation of the Museum of Contemporary Art in Sydney, completed in March 2012.
Glass Fibre Reinforced concrete, better known as GRC or GFRC, is a highly versatile building material that has been in use since the 1970’s. Made of high-strength glass fibre mixed with concrete, sand, and other materials, GRC is a lightweight and environmentally-sound form of concrete that offers superior strength and flexibility for projects of all types and sizes, from elegant tables and planters to the colossal renovation of 2010 World Cup Stadium in Johannesburg, South Africa.
Why GRC is better
What makes GRC different is that it can be used in virtually any application where traditional concrete is used, but with the advantage of being up to twenty times stronger and ten times lighter in weight than solid concrete. The lighter weight allows for greater design flexibility, lower transport costs, easier handling with less damage, and more economical building frames. Because GRC contains no steel, it is water-resistant, and can even be used in marine environments. GRC is also fireproof and acts as a thermal regulator when exposed to flame. Subjected to time as well as accelerated aging tests, GRC has proven to wear as well as or better than pre-cast concrete.
Because GRC can be molded into virtually any shape and cast hollow, it has been used in a variety of architectural and engineering applications such as wall panels and exterior cladding, decorative tiles, outdoor furniture, planters, retaining walls, park and landscaping elements, public art, security and noise barriers, marine structures, electrical and storm water pits, pollution control tanks, bench tops, bathroom floors and much more.
A brief history of GRC
The concept of reinforcing concrete, the most common building material of the 20th century, has been around for some time. Most concrete foundations, driveways and building components have reinforcement in them, usually steel. Russian scientists were the first to explore the potential of using glass fibres in cement prior to World War II, but their early experiments failed due to the alkaline environment present in Portland cement, which caused the glass fibres to quickly deteriorate.
The Great Britain Building Research Establishment (BRE) succeeded in making an alkaline-resistant (AR), glass fibre in 1967 by adding zirconium dioxide to the fibre manufacturing process. After the BRE finished its development work, with initial patents taken out by National Research Development Corporation, it handed over the commercialization of GRC to Pilkington Corporation in the U.K., who further refined the process.1
GRC usage in Australia and recent projects
While GRC is being used extensively in building construction projects across the Middle East and Asia, it has been slower to catch on here in Australia, with a handful of GRC manufacturers coming and going over the past few decades. However, according to industry experts, there has been a significant upturn of interest in GRC in the past few years, coinciding with the return of Australian professionals from the Middle East since 2008. As a labour-intensive material, GRC is a very popular and commonly used cladding material in the Middle East due to low labour costs, which makes the use GRC much less expensive than it is here.
According to Charles Rickard, a well-known structural engineer who wrote the original draft for the NPCAA2 CODE OF PRACTICE FOR GRC in Australia in 1999, the relatively low consumption of GRC for major architectural projects here in Australia is an unfavorable intersection of the 1.) industry always looking for the cheapest solution, and thus not being prepared to pay the price required to use different more interesting materials such as GRC in their projects and 2.) a lack of adequate, regular work leading to a shortage of suitable professional production facilities.
As GRC is a labor-intensive product, and in his opinion, too many projects using GRC are one-off custom designs requiring molds that are time-consuming and expensive to produce, and sometimes only used once. As such, architects need to recognize that design innovation needs to be applied with greater recognition of minimizing cost through repetition of shape.
Two major GRC projects recently completed here in Australia include the new extension to the Australian Catholic University in Melbourne (GRC Environments was the manufacturer) and the iconic renovation of the Museum of Contemporary Art in Sydney (pictured). The façades for both of these projects were engineer designed by Charles Rickard. Architect Sam Marshall won the completion for the $50 million plus extension/modernization of the museum and eventually chose GRC as the material best suited to achieving his vision.
The status of the GRC industry (due to the issues mentioned above) meant that the project strained its capability to the limit, but eventually achieved its task thanks to Precast Concrete Pty Ltd from Brisbane who produced a ‘brilliant’ result in conjunction with head contractor Watpac.
The state of the GRC industry in Australia
Unfortunately, projects containing large volumes of GRC can and do fall prey to budgetary constraints resulting in the deletion of GRC in their final construction, such as ‘Centra’ and now apparently, ‘Barangaro’ in Sydney. However, other large jobs remain on the drawing boards, particularly in Melbourne, such as the Illura complex designed by Ellenberg architects which uses a series of GRC columns that taper to give the façade a Dali-esque appearance.
Rickard hopes that projects like the ACU, MCA and others will show the industry that Australian manufacturers can produce GRC at the right price, quality, and time frame. On this note, he also believes that there is at last an upturn in manufacturing options here in Australia, with Precast Concrete in Brisbane, GRC Environments in Melbourne, Asurco in Adelaide, Quatro on the Gold Coast, Mascot Engineering in Sydney (precast chambers), as well as smaller start-ups.
Others also believe that the use of GRC in architectural and engineering applications in Australia is definitely on the rise again, due to rapidly changing regulations to the Australian Building Code, which call for more environmentally sound and energy efficient building methods every year.
Melbourne-based architect Craig Tan (who spent 5 years as senior designer working with David Adjaye in London who developed several GRC design projects), said that when he returned to Australia in 2007, he realized that many countries were miles ahead in their use of GRC. Due to stricter energy-saving standards since the 1970’s, the UK, US and Europe have been implementing energy-saving design into their buildings with the use of external insulation techniques such as GRC rain screens for some time now.
In addition to being energy efficient, GRC rain screens are not subject to the condensation build-up problems seen with sealed cladding systems. He believes that the benefits of these rain screens combined with evolving building codes are at least partially responsible for the notable increase in the use of GRC in Australia in recent years.
Where manufacturers are finding success
GRC in particular is seeing significant growth in civil engineering applications as well. According to Anthoni DeMarinis, Business Development Manager of Mascot Engineering Group in NSW (which started using GRC in 1984), growth has been ‘phenomenal’ over the past 5 years. Mascot is one of the leading producers of GRC drainage and storm water pits, electrical and communication pits, trench and channel grating, and pollution control containers in Australia, with branches in Perth, Melbourne, Sydney and Brisbane.
Due to ever-increasing demand for their GRC products from the plumbing, building, electrical, mining, rail and airport industries, they relocated their manufacturing plant from Sydney to Smithfield, which now boasts 4x their original capacity, capable of producing in excess of 25 000 tonnes of GRC per day.
DeMarinis feels this growth is in large part due to the many benefits of GRC, such as light weight and resistance to chemical corrosion and water, as well as the fact that information about GRC is more available and widespread. He added that while many in the trades are knowledgeable about GRC and using GRC in their projects, approximately 1 in 5 are still unaware of the many applications of GRC. As such, he predicts even greater growth in the future.
Another area where GRC has found successful and widespread application is in landscaping, outdoor furniture, planters, water features, and even public art. Growing demand is also been seen for kitchen bench tops, splash backs, wet areas and flooring. Because of the attractiveness and durability of GRC in these applications, as well as the wide range of classic cement, pigmented and stone-like finishes, it is a popular choice for adding functional and decorative elements to parks, malls, commercial buildings, hotels, retail environments and even private residences.
The future of GRC in Australia
GRC has proven itself to be a strong, long-lasting, and reliable material for a wide range of construction and beautification projects. Although its use is now well-integrated overseas in regions like the Middle East and Asia, in countries like Australia, the UK, Western Europe, and the US, economic factors have been playing a large role in the feasibility of incorporating GRC into major, large-scale projects.
The future of GRC in this country appears to hinge on a mixture of creative vision, budgetary considerations, and the ability of architects, engineers, builders and manufacturers to find a common ground of cost-efficiency and production capability. But as recent, successful projects here in Australia demonstrate, GRC is enjoying a well-deserved resurgence in popularity, paving the way for even more spectacular GRC projects in the years ahead.
1 New Scientist, Feb. 1, 1979
2 National Precast Concrete Association Australia