To reduce global CO2 emissions, investigations on alternative construction methods that can economically compete with conventional reinforced concrete construction were carried out. Besides the development of high-performance building materials, the prefabrication of building elements combined with composite structures helps to reduce emissions. Timber-concrete composites (TCC) have been mainly used in ceiling structures subject to bending stresses. In this paper, a yet unexplored application of TCC for the connection of wall elements made of cross laminated timber (CLT) is presented. The idea is to connect the prefabricated timber elements on-site in a tongue and groove system. The groove is inserted in the CLT narrow side and after assembly the residual space is filled with a special grouting mortar that is equivalent to a fine-grained concrete with high strength. Additional internal connectors are assembled in the two-shear connection to enable the load transfer of the connected timber walls through the internal concrete element. To determine the load-bearing capacity of the TCC joint experimental investigations were carried out. The different connection variants between CLT and concrete were tested on small-scale specimens. To generate the connection to the concrete cross section, steel connectors (screws and perforated plates) or notches as well as new connection types like glued-in textiles were inserted into the front side of the timber specimens. In combination with the various fasteners two different types of concrete were used for the experimental investigation. They differed in
the compressive strength. The one with the higher strength had mixed-in steel fibres. The results of the tests have shown that high shear strengths can be achieved with the designed tongue and groove joint in comparison to usual connection methods of CLT walls.