A concrete mix that includes Glenium 27 from MBT has been used on the Sydney’s prestigious 55-storey ‘World Square’ development - chosen because of its strength, durability, pumpability and ease of placement.
Glenium 27 is one of MBT’s range of new generation Glenium-Polycarboxylic Ether Hyperplasticisers which, which added to the concrete mix, produces high slump and also ‘self-compacting’ concrete. It also improves a number of other performance characteristics, including increases in both early and ultimate compressive, flexural and tensile strengths, increased bond to reinforcing steel and a significant reduction in shrinkage and creep. Additionally the extended slump life of Glenium 27 makes it suited to premixed concrete - allowing plant dosing to occur with little or no slump loss between dosing and placement. Importantly, this extended work life does not result in extended retardation with the mix still delivering normal on-site finishing times.
“We’ve used Glenium 27 in a number of projects, and as with the results we’ve achieved at World Square,” says Pat Vezza, from concrete construction contractors DeMartin and Gasparini. “As well as providing us with extremely flowable concrete, Glenium 27 has provided us with a mix that delivers excellent early strength and easily achieves the required 80MPa design strength while helping us to overcome the problems associated with pumping the mix from the ground up to level 55.
“Even though we only originally intended to use the Glenium 27 mix for the building’s main support columns and for a 100m x 3m beam wall, the performance and results were so good that we decided to use it for all of the pours above level 34.”
Source: Building Products News.