Structural and energy-related design of reinforced concrete sandwich facades

Illustration of various state-of-the-art reinforced concrete sandwich facades built in architectural concrete. Sources: Dreßler Bau GmbH, Stockstadt; Hering Bau GmbH & Co. KG, Burbach; Benno Drössler GmbH & Co. Bauunternehmung KG, Siegen; Laumer Bautechnik GmbH,
Massing

Effects of a thermal bridge: temperature distribution (left) and heat flows (right) in the area of a thermal bridge, using the example of a „floor connecting to an external basement wall“

Example of a reinforced concrete sandwich element;
top left: butt joint of two elements
center: perspective view showing the locations of load-bearing anchors (TA), torsional anchors (TOA) and horizontal anchors (HA) to connect the facing to the load-bearing layer (F = absorbable forces; x, y, z = coordinates)
bottom center: detailed view of an anchor penetrating the insulation layer
top right: section of a reinforced concrete sandwich element

Photo: : ENOTHERM, Bochum; Hering Bau, Burbach

Example of a reinforced concrete sandwich facade; left: thermogram, center: photo, right: element layout of the facade

Photo: : ENOTHERM, Bochum; Hering Bau, Burbach

Drawing of the reinforced concrete sandwich wall used in the worked example

Determination of the U value for the example of the reinforced concrete sandwich wall using the design aid

Interactive user interface of the „Design Atlas for Building Construction“ [4] enabling a quick search in the database of over 770 structural connections

Example of a structural drawing of a reinforced concrete sandwich facade

Reinforced concrete sandwich facades can make a major contribution toward achieving a high energy efficiency standard of buildings. In this respect, it is crucial to correctly evaluate structural components, joints and anchors. This area had long been characterized by insufficient available information. Today, recent studies and a related planning aid put designers and manufacturers in a position to fully utilize the energy performance of reinforced concrete sandwich facades when designing the entire building.

Today, designers need to meet a large number of carefully coordinated requirements when designing state-of-the-art buildings. During the last couple of years, the focus has been not only on design (see Fig. 1) and structural requirements but also, even more importantly, on the energy-related quality standard of the building, which will most probably become even more significant in the future. These considerations also include mechanical services (heating, cooling, ventilation etc.). Whereas these design aspects had previously been neglected and dealt with indepen-dently of each other, they...