Gulf Construction Online - Meva promotes safe concrete pouring

Dubai Review

Meva formwork helps shape a project.

Meva promotes safe concrete pouring

01 April 2009

MEVA, a leading global company in formwork technology which has supplied its systems for numerous projects in Dubai, is promoting safe concrete pouring practice through the use of a simple, practical, yet innovative method of safely calculating concrete pressure.

Accurately calculating and predicting the pressure that poured concrete will exert on the formwork, is an important task when planning on-site concrete works. Hence, sure knowledge of the expected loads will enable the site to choose the best building technique and suitable technical equipment.
Heike Huebner, marketing manager for Meva Schalungs-Systeme, says: “New concrete types with additives and different setting patterns underline the challenge of determining the load to be expected, especially since there is no definite experience to draw on. The methods used until now to gauge concrete pressure did not take today’s concrete types into account and so cannot be safely used. In addition, there is a definite trend toward delicate architectural structures, slim walls and sophisticated requirements on concrete finish. It is here that these new types of concrete are increasingly being used.”
Uncertainty about the chemical interaction between additives and their possible influence on the hydration progress and final setting is immense, he says.

Old methods
Earlier, concrete pressure was calculated using the English Ciria (Construction Industry Research and Information Association) Report or the German DIN Standard 18218. Both assume a basic concrete recipe consisting of three simple components as used in the 1970s (as set out in the DIN 1045 and 1048 standards).
“Concrete types used today no longer behave that way: slump and setting are distinctly different. In fact, self-compacting concrete in heavily reinforced, slim structures, exert higher pressures on the formwork,” he points out.

New methods
Meva engineers were the driving force in developing a simple, practical method of safely calculating concrete pressure. The theoretical formulae were tested in practice and brought on site for final verification. The results and insights have now found their way into the revised standard DIN 18218 and provide a secure basis for any construction engineer to work with, says Huebner.
The method covers concrete consistencies from F1 through to F5 and F6 as well as for self-compacting concrete. The new calculation method takes into consideration the setting behaviour of the respective concrete type, relative to consistency and temperature. The site can now determine the maximum pour rate from simple diagrams, he says.
All concrete types are depicted according to final setting, maximum concrete pressure and the respective pour rate. Thus, the increasing use of self-compacting and flowable concrete mixtures at today’s building sites is reflected in the method of predicting concrete pressure.
“The new, simple-to-use diagrams enable the site to safely determine the concrete load to be expected and thus choose the appropriate formwork to handle it,” Huebner says. “The advantage is twofold: assuming too much concrete pressure would be a waste of money, inventory and handling; while assuming too low a concrete pressure could endanger the safety of everyone on site.”
Meva claims to be the only formwork supplier to offer pressure gauges as a part of its rental and service programme. The device is described as being ideal in determining load capacities when flowable or self-compacting concrete are being poured.
The company, which has an active presence in Dubai, has supplied a variety of systems to projects in the emirate, including Al Manara Tower and Nagarajuna, Dubai UAE (Meva automatic climbing), Maze Tower (Meva guided climbing), Business Bay Executive Towers Kele and Al Yaqoub Tower, both on Sheikh Zayed Road, Dubai Marina, Aciko Tower Hotel, Mushrif water reservoir, IRR water tank, Dubai Electronic Centre and Al Attar Tower. It has also been involved with the UNEC project (Meva automatic climbing), a four-tower office tower complex, both in Sharjah.
Meva Schalungs-Systeme, which was founded in 1970 in Germany, offers sophisticated formwork systems, continuous product development and comprehensive services. Since its inception, it has launched numerous innovations, and is now among the leading, globally operating companies in formwork technology.
The company has a dense distribution network with branch offices, subsidiaries on different continents and specialised dealers, providing contractors worldwide with competent advice and back-up for the planning and construction of buildings.