Experimental Study on Bond-Slip Behavior between H-Shaped Steel and Gypsum Cover in SGFCG

Abstract EN

Nine push-out specimens of H-shaped steel with gypsum cover (HSG) are designed to study the bond-slip behavior between steel and gypsum in steel grid frame filling with cast-in-situ gypsum (SGFCG).

Three main factors including gypsum compression strength (fcu), gypsum cover thickness (Cs), and steel-gypsum connected length (la) are considered.

It is shown by the test results that the ultimate average bond strength is within [0.333–0.456] MPa, and the residual strength is about 90–98% of the ultimate strength.

Both gypsum cover thickness and steel-gypsum connected length have evident influence on the bond strength, while the effect of gypsum compression strength is not obvious.

Based on the test data, the formulas of average bond strength characteristics (τs¯, τu¯, and τr¯) and slip characteristics (Su and Sr) are established by statistical fitting.

Furthermore, the bond-slip constitutive relationship (τ¯−S) is recommended.