Al Gurg Fosroc, a leading supplier of construction chemicals in the Gulf, has reached new heights in the field of self-compacting concrete (SCC) admixtures.

SCC was poured at level 42 of Shangri-La Hotel on Dubai's Shaikh Zayed Road, at a height of 184 m - the first SCC application at such a height in the Middle East, Near East as well as Europe, the company says.

Mace International is the project manager while Norr Group is the consultant on this prestigious project. The main contractor is Al Habtoor-Murray and Roberts JV and Unimix, a leading ready-mix concrete supplier, has supplied the concrete.

The admixture used in this pour, included a combination of Structuro 335 and Structuro 480, which are new generation admixtures based on polycarboxylic ether.

According to Ghassan El-Nahhas, general sales manager (admixtures): "SCC was pumped on four structural transfer beams totalling to 800 cu m. The transfer beams on the top are meant to support the superceding structure."

There are many advantages of SCC over normal concrete, says Carl Munn, the company's business development manager.

"When concrete is placed into formwork, especially when there is a mass of reinforcement already there, it can be very difficult to make sure of no air entrapment. And it isn't until the formwork is removed the problem is seen, in the shape of voids or honeycombing, which require additional work to make good," he says.

"SCC flows easily around the reinforcement and into every corner and crevice of the formwork. It is poured in the same way as ordinary concrete but without the need for any vibration.

"Pseudo-plastic in nature, it rapidly passes around reinforcement, without segregation, at the same time expelling entrapped air and so reducing excess voids and honeycombing.

"Despite the fluidity, grout loss is lower than for normal concrete because of its cohesive nature.

"Another advantage is that it eliminates the need for compaction. This saves time, reduces labour needs and cuts energy demands and is also noiseless. It offers a better surface finish and improves site safety as many risks are eliminated."

Ghassan says: "SCC is approved and used by Dubai Municipality on several of its projects. Structuro 335 and Structuro 480 have also been used in a residential project in Sharjah and are also being specified on future projects. We believe SCC will be implemented in certain projects to overcome the complexity of construction, which will enhance its usage widely."

The product is suitable in areas where there are congested steel rebar structures, deep wall sections, transfer beams, awkward locations, water retaining structures, water tanks and residential zones, where loss of vibration is a major requirement.

The product is also cost effective. Even though the initial cost of SCC may be more than commercial concrete, the benefits, application and uses of SCC will overcome the initial cost in the long run.

Durability achieved using SCC may also exceed commercial concrete and this is a value addition, which cannot be priced, says Ghassan.