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Ice plants have been built in the gulf to keep concrete protected from high temperatures.

Construction Week discovers the benefits of emerging concrete technologies and how significantly they are set to improve the quality of buildings in the Middle East.

Recent events, such as the building collapse in Deira, Dubai, have proved that compromising on the quality of building materials, such as concrete, can lead to disastrous consequences.

Substandard systems may be acceptable for construction companies who wish to cut corners but, for contractors planning to construct buildings that will stand the test of time, new technologies designed to improve the life-span and quality of concrete have emerged.

"Customers are not only checking investment prices. Attributes like quality, flexibility, sustainability and service reliability are more important to them," insists Rupert Plersch, managing director of KTI Plersch, which specialises in concrete cooling.

Strengthening your concrete

English Indian Clays manufactures High Reactivity Metakaolin (HRM), which is a chemical admixture that is formed upon the thermal treatment of kaolinite (a clay mineral).

Metakaolin prevents Alkali-Silica Reaction (ASR) - a concrete related problem that has a well documented history all over the world. This is caused by the reaction of highly alkaline cement paste with non-crystalline silica, which is found in many common aggregates, such as sand or crushed rock.

The product of this reaction is a gel that surrounds the aggregate in the concrete mix. This gel increases in volume with water and exerts an expansive pressure inside the material, causing loss of strength of the concrete, finally leading to its failure.

HRM is a pozzolan - a material which, when combined with calcium hydroxide, forms compounds possessing cementitious properties.

Experiments have shown that a mineral admixture like Metakaolin reacts with calcium to further lower the PH, reducing the potential for the formation of the ASR gel.

"We have seen a significant number of developers moving towards Metakaolin. It is the first choice of pozzolan in developed markets like Europe and the USA," says English India Clays country manager for the UAE, Pramod Pillai.

The admixture, which can enhance concrete strength to more than 12,000 pounds per square inch, was first used in 1962 for large Brazilian dams. And, the product was incorporated into The Californian, a 23-story, US $200 million condominium tower that opened in September 2005 in Los Angeles, to prevent the tower from damage caused by earthquakes.

HRM is a Dubai Municipality certified product and has been use in UAE for eight years.

Waterproofing needs

The use of waterproofing chemicals is also vital for protecting concrete from long-term damage. It is easy to assume that buildings in the Middle East do not need protection from water absorption and corrosion due to the lack of rain. But, if we dig a while a few metres deep, especially in cities near the ocean, then we will find water, which can put foundations and ultimately a whole structure at risk of deteriorating.

Hycrete is a company that offers a liquid, which is designed to repel water and other contaminants which could attack the rebar of a structure.

"The Hycrete forms a long-chain hydrocarbon, which plugs all capillary pores and mechanically attaches itself to the sides of the structure to prevent water from entering," reports Hycrete vice president of international sales Peter Condy.

Stay cool

The high temperatures we experience in the Middle East can also cause damage to concrete before it even gets to a construction site. Therefore, concrete cooling is needed to prevent early setting.

KTI offers flake ice plants, mobile ice storages and ice delivery systems to meet this demand. Since 1992, the company has produced more than 1000 plants for concrete cooling all over the world and 90% of them were installed here in the Middle East.

"Depending on the recipe of the mixture and required concrete temperature we supply chilled water and ice directly to the batching plant," explains Plersch.

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