The advantages of the two different building construction materials, timber and concrete, can be used effectively in adhesive-bonded timber-concrete composite constructions. The long-term behavior was investigated experimentally on small-scale shear and bond specimens under artificial, alternating climatic conditions and on fullscale specimens under natural climatic conditions for an application in construction practice. The development of the shear strength and the deformation behavior under permanent loads were studied, focusing on the different material behavior of wood and concrete regarding changes in temperature and moisture. The general applicability of adhesivebonded timber-concrete composites in construction practice was proved in the investigations.
This paper discusses the impact of the natural frequency of multi-storey timber structures, focusing on force-based seismic design. Simplified approaches to determine the frequency of light-frame and cross-laminated timber structures are investigated. How stiffness parameters for simple two-dimensional analysis models can be derived from the different contributions of deformation...
Knowledge of friction behaviour under cyclic loading is important to predict the load bearing and deformation behaviour of test specimens for shear wall elements. Thus, a comprehensive literature research was made to collect knowledge about the impact s on friction coefficients. Furthermore, a small test series was performed to find out the influences on cyclic loading, loading speed and interlocking effects depending on the pressure perpendicular to the friction surface.
This paper presents new findings on adhesively bonded timber-concrete composites with prefabricated concrete parts. Hereby, timber and concrete are bonded solely with adhesive and no metallic connectors have been used. Because the achievement of a continuous bond proved to be a critical point in past studies, special attention is given to that issue. The application procedure of the adhesives is investigated in small-scale bond samples and the manufacturing process in full-scale composite beams with a span of 8 m and a comparatively new polymer mortar is used as adhesive as well as a common epoxy resin. Both adhesives proved to be suitable, although polymer mortars showed strong advantages in terms of applicability and bridging of gaps in comparison to the less viscous epoxy adhesive. The full-scale beams are tested under quasi-static and cyclic loading. The failure occurred more as a bending failure of the timber or compression failure of the concrete. A full bond could be achieved at all full-scale beams. Moreover, an analytical and a finite element model for the calculation of composite beams are presented and validated. It could be seen, that both deformation behavior and failure load are in good accordance with the test results.
A new type of interlocking timber-to-timber connection was designed to simplify the structural details and the mounting conditions between wall elements and ceilings or floor panels in timber frame constructions. An experimental test series on different connector geometries was performed due to the unclear component behaviour and failure mechanism in mode II. The connection types achieved sufficient capacity but do not reach the predicted loads according to EC5. Thus, a mixed mode failure of mode I and II obviously occurs. A design approach is provided recognising all influences on the load-bearing capacity.
Modern joinery machines are able to produce precise and complex wood-to-wood connections on a high prefabrication level. For this work, multiple tenon joints were tested to assess the load-bearing capacity and deformation characteristics. Four different geometries of tenon set-ups have been tested. The evaluation of the results shows significantly higher load capacities of multiple tenon joints compared to traditional mortise and tenon geometries. The deformation characteristics show that relocation of loads takes place if the bending capacity of the tenons is guaranteed. Failure of multiple tenon joints occurs with high deformations within the connection. The investigations show the high potential of multiple tenons compared to wood-to-wood connections used currently. Preliminary calculations of mortise and tenon joints show no satisfying accordance with experimental data.
The long-term behavior of adhesive-bonded timber-concrete composites is influenced by climaticchanges in temperature and relative humidity because of the different properties of wood, concrete and adhesive. Threedimensional material models, which take into account the hygrothermal and time-dependent behavior, were developed to predict the long-term behavior. The material behavior of the wood is highly influenced by the moisture content. Thus, the wood moisture content was calculated numerically as well as depending on the surrounding climatic conditions. The numerical models were validated with data from experimental investigations and applied to determine climatic conditions for further experimental investigations.
This paper deals with aspects of force- and displacement-based design of multistorey cross-laminated timber (CLT) structures. A method to determine the behavior factors for timber structures based on nonlinear static analyses will be discussed. Different types of analysis models are considered. Results of experimental investigations on connections and CLT wall elements will be presented as a basis for numerical simulations.