Caring for Australia's Concrete Industry

Cement Concrete & Aggregates Australia is a not-for-profit organisation of almost 80 years standing, and dedicated to its leading role in providing information, training, research and development, technical information and advisory services to Australia’s cement, concrete and extractive industries. CCAA also contributes to the preparation of Australian Codes and Standards. The association’s aim is to protect and extend the uses of concrete and other cement-based products by increasing knowledge, skills and professionalism in the concrete industry, a task carried out in part by maintaining awareness of new products, their energy efficient properties and uses, and their sustainability.

A BIT ABOUT OFF-FORM CONCRETE ELEMENTS

Concrete is the most commonly used construction material for both loadbearing and non-loadbearing projects. Its aesthetic, cost-effective and structural potential is most effectively harnessed by utilising the extensive range of constituent materials, surface treatments and moulding options available. Moreover, it is possible to achieve the most sought-after architectural off-form finishes without the need for additional, and often costly, applied finishes and materials.

To ensure that concrete construction’s high standards are maintained, CCAA wants every off-form architectural project to be successful, so they have formulated guidelines and advice to help overcome the intricacies of the task. High-quality off-form and architectural finishes don’t just make themselves, they require special care, skill and workmanship to be exercised by everyone in the production process, from the choice of constituents, to the process of production, and the installation.

• Designers must be aware of the minimum wall thickness to prevent scoring the surface during compaction, and keep an eye on the spacing of reinforcement bars to avoid honeycombing.

• Suppliers need to be made aware of special requirements such as colour control, low bleed rates, stringent slump tolerances and colour pigments.

• Formworkers must know of the limitations on reuse associated with off-form surfaces. The formwork must also be designed to accommodate the extra load of compaction, with the desired end result in mind.

• Concrete must be cured properly and uniformly.

• Finishes should be assessed at the appropriate time as colours may vary with time.

There are various other factors that will affect the quality and outcome of an off-form concrete surface including the type of element (wall, column, beam etc.); whether the concrete element will be created insitu or precast; and whether the surface will be smooth, or textured (such as roped, formlined or board marked).

CCAA has a compendious library of more detailed, up-to-date, fully-researched and professionally published information on these and other concrete-related topics for members of the building industry, which they are more than happy to provide.