Tailored concrete concepts for very tall cooling and solar updraft towers

Yared Assefa Abebe

M.Sc.

Leibniz Universität Hannover Hannover, Germany

yared.a baustoff.uni- hannover.de

Yared A. Abebe, born 1980, received his civil engineering degree in 2002 from the Univ. of Arbaminch. Before receiving his M.Sc. degree from the Leibniz Univ. Hannover in 2010, he had worked in different projects.

Currently, he is working on his research at the Institute of Building materials.

The record height of solar updraft towers would surely require application of modern super high- pressure pumps and pumping lines. However, such pumping operations might potentially lead to not only loss of stability of the concrete due to segregation and/or bleeding, but also a premature stiffening and thus poor workability of the concrete due to longer staying-duration in pumping lines. To this end, the paper presents a mix-design concept that has shown a promising prospect with regard to fulfilling the desired concrete characteristics. Moreover, some simplified concepts with regard to the production and usage of concrete for a 1000 m high solar chimney are presented. Concerning damages caused by acid attack on concrete surfaces of cooling towers, a new approach, which has significantly improved the durability characteristics of such concretes, are introduced. Also presented is an accompanying laboratory test procedure, which is specifically developed to measure the extent of the damage due to acid attacks.