Oils ain’t oils

National Precast outlines the benefits of low volatile organic compound products and how their use in the precast concrete sector is challenging perceptions in the Australian civil construction sector.Using environmentally and applicator-friendly coatings is a rising trend, with companies getting wise to the workplace health, safety and environmental (WHSE) benefits that these products endorse.

Amid a growing worldwide awareness about healthy living and sustainable construction methods, an array of low volatile organic compound (VOC) products have hit the Australian market and are challenging the common perception that all chemicals comprise hazardous substances. Several are used in the precast concrete space and can include sealers, hardeners, release agents and bond breakers.

Leaps ahead 

The precast concrete industry has made great progress when it comes to technology, and the use of WHSE-beneficial products before, during and after manufacture has almost become a minimum requirement.

National Precast’s Chief Executive Officer Sarah Bachmann says the range of low VOC products that are now available on the Australian market means there is no longer any reason to use products that include harmful chemicals.

“This means that using precast in a project can offer WHSE benefits, and that our projects here match international best practice in that regard,” she says.

“One of our industry partners – Dayton Superior – is an example of a company that is producing these environmentally-friendly products. These products are solutions that are found on worldwide construction projects, where performance at the highest level is both a request and a requirement.”

Dayton Superior Managing Director Brent Poll says it’s imperative to consider the impact of chemicals that are used in construction from a project’s get go.

“There is no stage in the product lifecycle where the choice of chemicals is more important than in a precast manufacturing facility,” he says.

Enhancing safety in the workplace 

With safety paramount in the factories of National Precast’s members, Ms. Bachmann says it’s important that workers aren’t exposed to harmful chemicals.

“Our members are committed to maintaining high safety standards for their workers in their factories. Release agents are used to minimise breakages, when precast concrete elements are lifted from their moulds,” she explains.

“Any breakage can cause risk to workers, so the use of high quality and effective release agents are important to ensure that workers aren’t injured.”

Release agents are applied to the mould before the concrete is poured.

As a job that is usually done manually, she says it’s important that workers aren’t exposed to harmful chemicals during this process.

“Using low VOC products minimises a worker’s exposure to hazardous substances,” Ms. Bachmann adds.

Exploring the options 

From sealers and hardeners, to bond breakers and release agents, the environmentally-friendly options are as extensive as the benefits they provide.

Ms. Bachmann says low VOC concrete sealers and coatings are ideal for densely-populated and sensitive environments.

“Sealers and other products that densify the surface and harden the concrete further not only seal against water, but they can also be useful in marine environments and areas that are prone to graffiti,” she explains.

“They can assist with the self-cleaning of the precast and ultimately have significant environmental benefits.”

Typically, precast concrete elements are factory-manufactured under cover on steel beds, and moulds can also incorporate fiberglass, plywood, urethane, other concrete-forming materials and form liners. Form release agents and bond breakers are used to assist the release of the concrete once it has cured in the mould.

“They prevent the concrete from bonding with the mould surfaces, and ensure a clean release. When properly applied, they can reduce the number of surface air voids and won’t interfere with the adhesion of subsequent coatings,” Ms. Bachmann says.

Optimal finish quality 

Precast elements are predominately manufactured on high quality and well-maintained steel moulds, which results in a high quality finish.

“While Class 2 is the usual off-form specified finish for most precast walling, a borderline Class 1 finish can often be the result,” says Ms. Bachmann.

“While Class 1 specifications should only ever be used for single pour elements that are of a monumental nature, specifying a Class 2 finish and sometimes ending up with a Class 1 finish can be a massive bonus for architects and clients.”

She says National Precast members are well-versed and experienced when it comes to the use of release agents and bond breakers, which means the integrity of the maximum possible achievable quality is preserved.

“Our members know which release agents are most effective in their function, while ensuring the off-form surface of the precast isn’t blemished in any way.”

Benefits beyond the factory

Ms. Bachmann says the benefits of low VOC products extend far beyond the precast factory.

“Not only do workers benefit from using chemicals that are not harmful to the environment and workers, but the end users of the precast structure benefit as well,” she explains.

“Using low VOC products benefit occupants for the lifetime of a structure. It’s important to know that occupants – whether they be office workers or families – aren’t exposed to chemicals that will emit harmful substances.”

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