Flat Slabs with Different Longitudinal Reinforcement Ratios Under Horizontal Cyclic Loading

Citation:
Rossi, M.  2021.  Flat Slabs with Different Longitudinal Reinforcement Ratios Under Horizontal Cyclic Loading. NOVA School of Science and Technology. (António Pinho Ramos, Brisid Isufi, Eds.)., Caparica: NOVA School of Science and Technology

Thesis Type:

MSc Thesis

Abstract:

The following dissertation studies the behavior of flat slabs when subjected to constant vertical loads and cyclic horizontal displacements, as a continuation of previous studies developed at FCT/UNL. The main focus of this research is to study the influence of flexural reinforcement on the seismic response of flat slabs. Therefore, three reinforced concrete flat slabs with varying flexural reinforcement ratio were tested, two having the same top reinforcement ratio of !=0,64% and one with !=1,34%. One of the specimens with lower longitudinal ratio was reinforced with studs as specific punching shear reinforcement. All slabs had overall dimensions of 4,15 × 1,85 × 0,15 m3 and a gravity shear ratio, ratio between the gravity load and the punching shear resistance, approximately equal to 55%. For a more complete analysis the results obtained were compared to two other specimens from previous experimental campaigns also conducted at FCT/UNL. These two slabs were designed with top flexural reinforcement ratio (!=0,96%) that lies between the two tested in this dissertation, one with no shear-reinforcement and the other with headed studs. Results showed that the reduction of flexural reinforcement resulted in a more ductile behavior of the specimens and in a higher drift capacity. The high flexural ratio added to one specimen improved the maximum unbalanced moment capacity but also made the slab fail in a more brittle mode. As expected, the specimen with shear headed studs supported the highest drifts and ended up not failing during this experimental campaign, reaching the test setup upper limit.

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