Monolithic equivalent stiffness of precast columns with grouted splice sleeve connections

Abstract

The aim of this paper is the validation of monolithic equivalent stiffness applied to precast columns with grouted splice sleeve connections, wherein spliced precast elements have been compared with continuous monolithic elements. The experimental investigation has been carried out with bending tests for two spliced elements (L1 and L2), comparing the deflections along these elements with the results obtained from two monolithic elements (M1 and M2). The grouted splice sleeve connections have been characterized by their rotational stiffness (moment-rotation relationship), ultimate strength, and ductility, allowing the calibration of the equation for the secant stiffness according to ABNT NBR9062:2017. Based on the experimental results, the effective deformation length within the connection zone obtained was Led = 20ϕ, corresponding to a secant stiffness of Rsec = 77,785 kN∙m/rad. Although relative rotations have been observed at the grouted splice joint, the deflections along the precast spliced elements were very close to the deflections along the monolithic elements. A strong convergence for all phases of the load x displacement curves has been observed, as well as good approximation in terms of rotational stiffness, strength and ductility. Therefore, based on the analysis of the experimental results, the requirement to define the monolithic equivalent stiffness for the precast columns has been met.

Detection of Sleeve Grouting Compactness Based on Acoustic Emission Technology

“…The effective connection between prefabricated components has been the focus of many researchers and it is also the basic condition for the popularization and application of reinforced concrete prefabricated buildings. Grout sleeve connection, because of its good seismic and bearing performance [ 3 , 4 ], is currently the main connection mode of prefabricated components used in reinforced concrete prefabricated buildings [ 5 ]. However, under the complex construction conditions on site, grout quality problems such as less grout and leakage often occur in the grout sleeve, which leads to the insufficient grouting of the sleeve.…”