A New Approach to Improving the Seismic Performance of Existing Reinforced Concrete Buildings Using Laminated Timber

Following recent earthquakes in Van, Istanbul, Izmir, and Kahramanmaraş, concerns have once again been raised regarding whether existing buildings possess adequate seismic performance and the necessity of strengthening those that do not. A common theme in all related discussions is how to improve the seismic resilience of the existing building stock most efficiently and cost-effectively. In particular, seismic retrofitting efforts should be accelerated for residential buildings in areas where urban transformation has not been feasible due to low added value, as well as for public buildings in smaller settlements and school or dormitory structures in rural towns and villages. In this study, the seismic performance of a reinforced concrete (RC) frame was evaluated using the nonlinear single-mode pushover analysis method in accordance with the Turkish Building Earthquake Code (TBEC). For frames with inadequate performance, a retrofitting method was proposed using glued laminated timber (glulam), a renewable and sustainable material, as diagonal bracing. This intervention aimed to improve the structural performance to an acceptable level specified by the code. The results indicated that glulam braces can effectively enhance the seismic performance of RC buildings and may be considered a viable solution for this purpose.