📽️A short time-lapse from a recent test on novel precast concrete wall connections!

Project collaborators: 

Dr. Lisa Tobber (University of British Columbia) and Prof. Geoff Rodgers (University of Canterbury)

🏢 How to prevent hollow-core floors from collapsing under strong earthquake shaking?

In this recent paper, we present the development and experimental evaluation of seismic retrofits for precast concrete hollow-core floors. Using a full-scale super-assembly test, we investigated how two newly developed retrofit systems perform under severe cyclic earthquake demands and whether they can preserve the gravity load path even after substantial floor damage.

Key findings:

✅ The new retrofit systems successfully prevented floor collapse throughout testing, up to a peak inter-storey drift of 4.9%.

✅ The strongback retrofit effectively maintained an alternative gravity load path and limited vertical floor deformation, even when subjected to approximately twice the design gravity load.

✅ The cable-catch retrofit also performed well in preventing collapse, although practical design and installation challenges may make it a less attractive option in real applications.

Here is a link to the open-access paper: https://doi.org/10.1002/esp4.70034

Precast hollow-core floors are used in buildings around the world. But how do they perform in earthquakes?

In our new open-access paper, we study how reinforced concrete moment frames interact with precast hollow-core floor systems under seismic demands. We track the evolution of floor damage, identify where deformation incompatibilities arise, and discuss what this means for the overall system performance.

Key findings:

✅ Floor damage concentrates near the supports, with hollow-core units seated close to columns showing heightened vulnerability.

✅ Cracking in the unreinforced hollow-core floor webs can initiate under low drift demands (~0.4–0.5% drift), within the elastic range of a typical RC frame.

✅ Earthquake-induced cracking can significantly decrease the residual gravity load-carrying capacity of hollow-core floors.

Here is a link to the open-access paper: https://lnkd.in/gynZYXVX