Increasing the shear capacity of reinforced concrete beams using pretensioned stainless steel ribbons

Abstract

In this work, the second part of an experimental campaign investigating the efficiency of an alternative retrofitting method for increasing the flexural and/or shear capacity in reinforced concrete beams, based on the use of prestressed stainless steel ribbons and steel angles, is presented and analytically reproduced. This group of tests focuses on the ability of the adopted retrofitting method to improve the shear strength and ultimate deformation of reinforced concrete structural elements. As described in a companion paper, the adopted retrofitting method is alternative to traditional techniques of reinforced concrete retrofitting, being easy to install and usually reversible, and characterized by high fire resistance and avoiding corrosion. The experimental results obtained from shear tests carried out on nine reinforced concrete beams are presented. The efficiency of stainless steel ribbons as shear reinforcement that wrap a portion of cross‐sectional depth are analyzed, and the interaction between existing stirrups and stainless steel ribbons examined. The tests results are critically analyzed, highlighting the ability of the retrofitting method in increasing the shear strength and ductility of reinforced concrete beams. The experimental shear strength was also analytically evaluated by extending the theoretical approach of the fib Model Code 2010 formulation, originally suggested for reinforced concrete beams with or without stirrups.

Experimental tests on corroded prestressed concrete beams subjected to transverse load

“…The loss of strength of the prestressing system strongly influences the load‐bearing capacity of the beam . Therefore, it could be adequately taken into account in more refined models, also if they were originally proposed for not corroded structural elements …”

Seismic Vulnerability of Segmental Bridges with Drop-In Span by Pushover Analysis

“…In this research, the application of both modal dynamic analysis and pushover techniques to the assessment of the seismic vulnerability of bridges are conducted, highlighting that they must be applied with special care. Moreover, insight is provided for the application of POA as a tool for the preliminary evaluation of the structural deficiencies to be filled with seismic strengthening interventions of different natures [32][33][34]. The seismic vulnerability in the longitudinal and transverse directions is investigated for a framed bridge with a clamped deck to the pier and for a continuous box girder disconnected from piers by comparing the modal dynamic analysis.…”

Ultimate behaviour and serviceability analysis of stainless steel reinforced concrete beams

“…There has been extensive research in recent years into the behaviour of structural stainless steel including retrofitting applications [7,8], the flexural behaviour [9,10], compressive response [11,12] and the mechanical characteristics [13][14][15]. However, most of this research has focused on bare stainless steel sections, rather than stainless steel reinforced concrete which is the main concern of the current paper.…”