P Rathish Kumar

Seismic retrofit of square reinforced concrete piers by ferrocement jacketing

An experimental investigation was conducted to strengthen shear deficient reinforced concrete columns using ferrocement jacketing. Three scale model specimens, identical to the actual bridge piers, were tested. One of the piers was tested under as-built condition while the other two were strengthened with layers of wire mesh before being tested. All the specimens were subjected to a simulated seismic loading and constant axial load. It was observed from the experimental results that the ferrocement-jacketed specimens exhibited enhanced stiffness, strength, energy dissipation and ductility and the mode of failure changed from brittle shear failure to a ductile flexural failure. The control specimens failed by shear at a relatively low lateral displacement. A finite element model was developed and the results obtained from the numerical analysis compared well with the experimental results. A design methodology for strengthening piers with square/rectangular columns with inadequate shear strength using ferrocement jackets is also presented.

Interaction Curve for High Performance Ferrocement in Biaxial State of Tension

abstract Ferrocement′s attribute as a thin reinforced concrete and laminated cement based composite enables numerous applications where strong and tough protective shell is needed. It is used in the construction of cylindrical and spherical shells as liquid retaining structures. The stress condition at a point in such shell structures is biaxial state of tension-tension. A study on the behaviour of ferrocement in biaxial state is important for establishing a rational design. The authors carried out a full-fledged investigation on ferrocement under different biaxial stress conditions. The present investigation deals with the study of ferrocement in biaxial tension-tension based on hollow cylindrical specimens. An interaction curve is proposed to estimate the strength of ferrocement in biaxial tension-tension. The relationship between octahedral normal and shear stress is also presented.