Experimental Analysis of the Structural Behavior of Hybrid Concrete 3D Printed-Cast Beam Systems (2025-06)¶

As the performance and quality of extrusion-based concrete printing systems increase, the search for an appropriate reinforcement technique for additively manufactured structural concrete components continues. A hybrid solution is investigated in this work, in which a beam is composed out of two ary elements: a prefabricated traditionally reinforced bottom chord, on top of which an extrusion-based ary printed geometry is added. By combining both systems, a composite printed-cast beam with longitudinal reinforcement is obtained. At the same time, the printed segment allows for the implementation of geometrically complex features that can be structurally optimized. Structural testing is performed based on flexural loading to check the performance of these hybrid systems. Both full and optimized beam sections are subjected to the loading while monitoring the beam’s behavior. The test data is in analyzed to assess the failure mechanisms occurring for each of the configurations, their consequence min on the maximum load-bearing capacity, and the degree to which the hybrid system works as a monolithic entity. The results indicate the importance of the interlayer bond between the two constituting components, as premature failure of the interface leads to lower capacities and local failure of one of the two constituent parts of the beam. Steps should be taken to increase the strength of the bond or structural connection between the printed and the cast concrete. Further, a first analysis of the strains and stresses in the configuration with the optimized cross-section indicates possible shortcomings of the cross-sectional analysis approach in the case of non-prismatic cross-sections with added geometric complexity.