Modal Identification of a CDW-Based Structure

Construction and demolition waste (CDW) arises from activities such as construction, maintenance, partial or total demolition of buildings and civil infrastructures. It consists of heterogeneous materials with high potential for recycling and re-use. For this reason, innovative technologies are being developed to produce prefabricated elements, for both structural and non-structural applications, with high degree of CDW recycled materials. The present paper deals with numerical and experimental investigations performed on a CDW-based structure. A Finite Element Model of the experimental mock-up is assembled to numerically predict its modal properties. Considering that the overall performance of structural assemblies with CDW-based components depends on the performance of mutual connections between precast components, output-only modal identification tests have been carried out to validate the numerical model. Moreover, an experimental campaign was performed by means of shaking table tests, using acceleration time histories according to AC156 requirements, with increasing intensity level. Natural frequencies and corresponding mode shapes have been estimated at each loading step to investigate the effect of increasing structural damage on the dynamic properties of the structure.