BUILDING: Eco-Paving Block Rocks The Boat
Recent Western Cape Business News
A Cape Town venture is making its mark in far-off Australia. In 2007, Structerre Engineers was approached by Geraldton Boatlifters Ltd to design the necessary infrastructure for a new commercially operated boat lifter facility featuring a travelling boat-lifter weighing 100 tons - capable of lifting 200 ton boats with a beam of 10.2m - a docking bay, lifter runway and a 1.2 hectare hard stand area.
Located on the NW Re-claim area of the Geraldton Fisherman’s Wharf, the operation will offer wash-down, sand blast and private shed services, fenced with a security system so that boat owners can store and retrieve their vessels in a secure environment.
Structerre Consulting Chartered Engineers saw the opportunity to apply a new eco-friendly drive-over paving block, Terracrete, which had been introduced to the Western Australian market from Cape Town a few months earlier.
Manufactured by Geraldton Blockmakers under license from Terraforce, the interlocking, hollow core concrete paving system offered the desired cost effectiveness, ease of installation and environmental compatibility. In addition the block would be able – according to its design – to handle the pressure from a 300 ton boat lifter moving at about 5km per hour. A permeable eco-friendly surface was the prime motivator for specifying Terracrete apart from the positive cost implications.
After conducting considerable research and experiments to achieve a concrete mix of superior strength for the manufacture of the blocks it was decided on a 40 MPa concrete mix with 5kg of EPC BarChip ‘Macro’ (42mm long by 1mm in diameter) added per cubic meter mix, to stop the blocks from fragmenting when the wheels of trucks and lifter turn.
The fibres are manufactured by Elasto Plastic Concrete (EPC) from minimum 550MPa high tensile strength modified polyolefin plastic, and similar to steel rebar, receive a contoured surface embossing treatment to maximize bond with a cement matrix. The base, polyolefin, is highly resistant to the majority of aggressive agents and will never oxidize when exposed to the conditions which cause steel to rust. BarChip fibres also improve concrete ductility, toughness, crack control, fire resistance and long term durability.
The blocks (100 mm thick) are underlain with 100mm of compacted sand over a sand sub-base of gritty sand and rubble, compacted to greater than 95% relative dry density.
Construction commenced in November 2007 after the blockmaker commissioned the new block press from Profile Concrete Equipment, the Cape Town based designer and supplier of quality construction equipment.
The Australian contractor managed up to 1000 square meters in five days with three workmen and has placed 6000 sq m so far. The blocks are finally filled with 5 to 7 mm washed granite gravel before final compaction with a rubber pad compactor.
Test results of the blocks and cylinders have revealed that during whole block crushing tests the press was able to deliver 190 ton pressure which left the blocks unharmed.
Business News Sector Tags:
Fax 2 Email
Study IT Online
Work from Home