Effect of sleeve length on deformation properties of grouted splices
Tests on 12 grouted splices were performed to investigate their deformation properties under tensile loading. Test variables included diameter and type of spliced bars and the size of splicing sleeves. Finite element method based models of the splices were built, verified and used to investigate the effect of sleeve length on the deformation properties of the grouted splices. The sleeve length significantly affected the failure modes and further affected the splices’ deformation properties. A recommendation was proposed to maximize deformation properties of a specific splice by using a critical sleeve length associated with failure mode of bar fracture.
GROUT-FILLED PIPE SPLICES FOR PRECAST CONCRETE CONSTRUCTION
The effect of confining entire members or parts of members, such as beams and columns, is known to strengthen the bond between the concrete and reinforcement. In this paper, the effect of confining the grout that surrounds isolated, single reinforcing bars on the bond strength between the bar and the grout is investigated. Grout-filled steel pipe splices with differnet parameters and geometrical design were prepared and loaded in axial tension until failure. The test specimens are described and the test results are presented, with discussion and analysis in light of existing theory. The experimental results show that a generic and inexpensive reinforcing bar splice for field connection of precast concrete members can be achieved using grout-filled standard steel pipe.
Mechanics of deformable directed surfaces
Abstract The paper develops a simple, yet complete and consistent non-linear dynamic thermo-elastic shell theory based on the concepts of a two-dimensional directed continuum. The constitutive equations are postulated in a general form. Stress-strain relations are derived using the equation of energy balance and the two entropy production inequalities, which are rewritten in a special form. The linear theory is discussed in detail. The structure of the stress-strain relations is presented in the most general form and then specialized to concrete examples, in particular, to the classical shell theory, using their invariance properties with respective to certain symmetry groups. The elastic moduli are determined by demanding the coincidence of the frequency dispersion surfaces obtained using the two-dimensional theory with the lowest foils of the corresponding surfaces resulting from the three-dimensional theory of elasticity.