AN innovation in concrete pavement construction was recently launched in Johannesburg, pointing the way to the future of external hardstands, according to Hannes Engelbrecht, Concrete Unit Business Director at Chryso Southern Africa.
The pioneering solution – Optipave VRS – is a collaboration between leading players in the field. It combines the volumetric retraction stability (VRS) additive Link EVR from RCR Industrial Flooring, thin concrete paving (TCP) short-slab design technology and fibre-reinforced concrete.
“Chryso EasyFinish is a macro monofilament fibre that is engineered to replace steel mesh or steel fibres in concrete,” said Engelbrecht. “It is specially designed for concrete reinforcement and is shaped to create a smooth concrete surface finish, improving durability and mechanical properties.”
Link EVR reduces shrinkage and curling in concrete slabs, and also prevents superficial micro cracks known as crazing. It makes concrete less porous, improving its freeze-thaw behaviour as well as its resistance to liquid spillage and abrasion.
The Monofloor TCP design ensures that only one set of wheels can load each slab at any one time, reducing the flexural stress and changing the failure mode. The result of this is that a thinner slab can be cast for the same loading.
“Together, these technologies solve recurring problems in conventional external concrete pavements and hardstands. Optipave VRS, a technology from the RCR Industrial Flooring Group) reduces tensile stress in the slab, eliminates the negative effects of curling and pumping, reduces slab thickness, and allows minimal joint opening and maintenance.”
Engelbrecht said the Optipave system is also environmentally friendly as it has a low carbon footprint, absorbing just 500 g/m2 of carbon dioxide. It is recommended for a wide range of applications including highways, industrial pavements, low-traffic roads and parking lots.
“We believe that the Optipave system has a bright future due to its competitive construction costs and ease of installation. The optimised load distribution system and latest technologies in concrete also give Optipave a longer lifespan. This further enhances its cost effectiveness.”
The launch, which took the form of a practical demonstration where sample panels were cast, raised the interest of contractors, property developers and consulting engineers alike.