Experimental Investigation of Shear Connection in Precast Concrete Sandwich Panels with Reinforcing Ribs

Area of Science:

• Structural Engineering
• Materials Science
• Building Physics

Background:

• Precast concrete sandwich panels (PCSP) offer thermal efficiency but require robust shear connections.
• Traditional shear connectors can create thermal bridges, compromising energy performance.
• High-performance concrete (HPC) in PCSP necessitates advanced shear transfer mechanisms.

Purpose of the Study:

• To experimentally investigate the shear connection performance in lightweight PCSP.
• To evaluate the efficacy of polymer-based thermal insulation and CFRP shear reinforcement.
• To compare different rigid insulation materials for shear ribs.

Main Methods:

• Full-scale four-point bending tests on seven PCSP specimens.
• Comparison of Purenit, Compacfoam CF400, and Foamglass F as shear rib insulation.
• Assessment of varying amounts of CFRP shear reinforcement.
• Evaluation of reinforcing ribs and inter-rib insulation effects.

Main Results:

• Panels with Purenit and Compacfoam CF400 insulation showed superior load-bearing capacity over Foamglass F.
• Increased CFRP reinforcement enhanced load capacity but had minimal impact on stiffness.
• Experimentally determined composite interaction coefficient (α ≈ 0.03) indicated partial shear interaction.
• A strut-and-tie model provided conservative predictions of load-bearing capacity.

Conclusions:

• Rigid polymer insulation combined with CFRP reinforcement provides efficient shear transfer in PCSP.
• This system avoids thermal bridging, contributing to lightweight and thermally efficient building envelopes.
• Purenit and Compacfoam CF400 are suitable insulation materials for these shear connections, unlike brittle Foamglass F.