COMPARATIVE LIFE CYCLE ASSESSMENT OF TIMBER-CONCRETE-COMPOSITE WALLS WITH CONCRETE AND CLT-WALL ELEMENTS

In this study, Life Cycle Assessment of a new hybrid timber-concrete wall element was conducted. Furthermore, the results for the hybrid wall element were compared with the LCA results of a functional equivalent reinforced concrete wall element and a cross-laminated timber wall element. The thickness of the cross-section of the wall element (1 m² wall area) varied dependent on the applied load which was equal for every construction method. Modules A1-3, B4 as well as C1-4 and module D were considered. The results were analysed in terms of Global Warming Potential. The evaluation of the results indicated that, from an environmental impact point of view, the concrete-wall element is the least-reasonable option. The CLT wall element is the most suitable for small loads. However, with increasing load, a tipping point was reached. From this point on, the hybrid wall element showed lower environmental burden than the CLT wall element. This is because the thickness of the CLT used for the hybrid wall element and hence, its volume significantly increased compared with the volume of the hybrid wall element. Dependent on the applied load level, the difference in thickness among the cross-sections of the three construction methods can vary significantly.