Study of ferrocement bolted connections for structural applications.

Abstract

The objectives of this study were to: (1) investigate the behavior of bolted ferrocement shear joints; (2) study the structural performance of bolted ferrocement moment resisting joints; and (3) evaluate the structural performance of the connections of a typical section of a ferrocement panelized housing unit. An experimental and a finite element investigation were performed to study the behavior of ferrocement bolted shear joints. In the experimental program, thirty-two pin-loaded ferrocement plates and eight control specimens were tested. The test variables were the type of mesh, mesh orientation, number of mesh layers, and ratio between end distance and hole diameter (e/d). The failure modes observed were cleavage for e/d = 4, and net-section tension and crushing for e/d = 6. The finite element program ABAQUS was then used to obtain the stress distribution along the critical sections as well as the pressure distribution around the loaded hole. Limit analysis was also utilized to derive prediction formulas. An experimental program was undertaken to study the behavior of ferrocement bolted moment resisting joints. Eighteen ferrocement moment joints and four control specimens were tested under flexure. The parameters investigated were the number of mesh layers, corner distance of the first bolt, number of bolts, and moment modes (closing and opening corner modes). Most joints failed by premature cracking along the corner section. The bending capacity of the joint ranged from 36% to 90% of that of the control plates. The joint performance was improved by more than 50% when a fillet was added, and the failure crack was moved from the corner to one of the legs. The fillet was more effective in the elements subjected to the opening mode moment. A finite element analysis was carried in a section of a ferrocement housing unit. The program ABAQUS was utilized. The loads transferred by the individual bolts and the distributed moments along the corner regions were obtained. Dead load and wind loads were considered. The analysis showed that the connections could sustain the load with 2 layers of mesh.