Joint and tie hole pattern in focus

Extremely successful new buildings on the campus in Lemgo

The university requires more laboratories, offices, seminar rooms, lecture halls and storage rooms and is now looking forward to using the new buildings on the campus. House 10 and House 11 have square floor areas of 1,700 and 935 m² respectively, both consisting of a ground floor and two upper floors. PORR Hochbau GmbH, formerly Oevermann Hochbau GmbH, a prestigious regional construction company, was responsible for carrying out this project.

MietePlus – all inclusive
Three MEVA wall formwork systems were used by the team led by construction manager Lukas Kettler and foreman Michael Feismann for varying requirements. The construction company decided to commission MEVA’s Rhine/Ruhr office to supply the formwork within the scope of the comprehensive MietePlus package. This ensured costing certainty from the start of the construction work up to its completion, as besides rental equipment and logistics, MietePlus also includes all other services such as cleaning and repairs.

Floor slabs and strip foundations were poured using the hand-set formwork AluStar (panel area of 430 m²). The basis for both buildings was thus quickly laid. The robust Mammut 350 formwork was used to pour columns and Mammut XT formwork was used for the buildings’ walls.

Prepared for SB3
Before delivery, all Mammut XT (990 m²) and Mammut 350 (47 m²) panels were prepared by MEVA to achieve SB3 architectural concrete quality – as were alkus all-plastic facings for compensations, reveals and lintels in areas with more stringent requirements. In some areas SB3+ quality was also required, which was achieved through finer grinding and additional seals to prevent concrete bleeding. More than 670 m² (House 10) and 200 m² (House 11) of the wall surfaces now shine forth with surfaces that are worth seeing. The columns were also constructed in SB3 quality. The maximum pouring height was 6.30 m in House 11 (two height-extended 350 cm high panels) and 5.55 m in House 10 (350 + 125 + 125 cm).

Formwork planning is teamwork
The principal and the architect didn’t want run-of-the-mill construction but rather set great store by squeaky clean architectural concrete surfaces. At times, this made the formwork planning a challenge for MEVA, but at the end of the day the desired results were always achieved. For example, to avoid compensations in the 24 cm thick walls to the greatest extent possible and to fulfil the requirements of an SB3/SB3+ finish, the use of corners on the Mammut XT formwork was dispensed with entirely. The planning featured only straight walls with rebend connections.

Particular attention was given to the balanced joint and tie hole pattern that strongly influenced the entire planning process. Last but not least, numerous door and window openings also complicated the production of the optimum grid pattern. Hence, in close cooperation with the construction manager, the engineers and the architect, the optimum solution was defined and implemented in each case.

Advantages exploited using Mammut XT
The construction company Oevermann decided up front to profit from the flexibility of MEVA’s Mammut XT formwork. This has fully integrated, flush combination tie holes and allows three different tying methods to be used. During this project, single-sided tying using XT taper ties was used for the ground floor. For the subsequent storeys with wall thicknesses of 32 cm, conventional tying using tie rods, plastic tubes and cones for plastic tubes was the ideal choice.

As the work was performed using a large number of rebend connections to reinforce the construction joints, no anchors were to be planned in the adjacent wall sections. This was due to the high expectations with regard to the finish as well as technical considerations, as due to the rebend connections the tie rods could only be used with difficulty or – at wall intersections – could not be used at all.

MEVA systems:

• Mammut XT wall formwork
• Mammut 350 wall formwork
• AluStar wall formwork

Project:
New buildings at the OWL University of Applied Sciences and Arts, Lemgo, Germany

Principal:
Bau- und Liegenschaftsbetrieb NRW, Bielefeld office, Germany

Contractor:
PORR Hochbau GmbH, formerly Oevermann Hochbau GmbH

Engineering and support:
MEVA Schalungs-Systeme GmbH, Rhine/Ruhr office