Introduction:

Concrete has been facing several challenges continually. Newer concretes with special capabilities are being developed and used. The challenges posed by high-rise structures are many, the most important is being able to pump the concrete to great heights with very good flowability. Highly flowable / self-consolidating, yet cohesive concrete which results in high strength and durability are the major challenges. The sky-scrapers are taking concrete to higher altitudes. Concrete may be required to be pumped to almost a kilometre in the City of Jeddah's Kingdom Tower!