Australian company Boral has agreed to sell its North American Fly Ash business to Eco Material Technologies Inc. for US$755 million (around AU$1 billion) and is planning to focus more on its domestic business.
“This transaction will complete Boral’s portfolio realignment and strategic refocus back on its construction materials business in Australia,” the company stated.
Boral, a Gold member of the Concrete Institute of Australia, owned and operated building products and fly ash businesses in the US for about 40 years. Now looking at the Australian summer, Boral has warned about the importance of taking precautions when working with concrete in the hotter months and has advised how to minimise chances of early cracking.
Hot days, wind and low humidity in combination or separately can cause cracks so when concreting it is imperative to prevent early loss of water from the concrete, according to the company. Pavements such as footpaths, slabs and driveways are particularly vulnerable as they have large, exposed surfaces that maximise water evaporation during setting.
Boral advised to avoid concreting in these conditions and thoroughly dampen the area where the concrete is to go or use plastic sheeting. And ensure there are enough workers and equipment available to place the concrete quickly.
“Vibrating is essential for compacting concrete, expelling unwanted air and preventing other forms of cracking,” the company said. “Frequent applications of an evaporation retarder such as aliphatic alcohol during placement and during the finishing processes will help prevent water evaporating from the surface.”
Prompt application of a curing compound is also particularly important and to plan adequate joints and cut joints as soon as possible. Then, provide shade and windbreaks to protect the concrete from weather extremes, particularly after finishing. Damp hessian is good for protecting fresh concrete from the sun and builder’s film and wooden stakes make for an economical windbreak, according to Boral.
Image: Boral is supplying concrete, cement, fly ash and quarry materials for the Melbourne Metro Tunnel.