Shear and flexural strength prediction of corroded R.C. beams G. Campione ⇑ , F. Cannella, L. Cavaleri Dipartimento di Ingegneria Civile, Ambientale e Aerospaziale e dei Materiali (DICAM), Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy highlights  Experimental versus analytical prediction of effects of general and pitting corrosion on steel bars.  Experimental versus analytical prediction of effects of general and pitting corrosion on R.C. cross-section if flexure.  Experimental versus analytical prediction of effects of general and pitting corrosion on R.C. beams in shear.  Case of study for strength and ductility degradation in flexure and shear of R.C. beams under natural corrosion scenarios. article info Article history: Received 16 January 2016 Received in revised form 21 April 2017 Accepted 12 May 2017 Keywords: Shear-moment interaction Corrosion Bond Pitting Flexural response abstract The purpose of the work was the study of the structural safety of R.C. beams subjected to corrosion pro- cesses though the derivation of moment-curvature diagrams and moment-to-shear interaction diagrams. Normal-strength reinforced concrete beams with longitudinal bars in the presence of transverse stirrups and subjected to corrosion processed are considered. Experimental results available in the literature related to corrosion processes, for steel bars, crack openings and bond degradation due to rust formation are reviewed. Then analytical laws relating to crack opening, bond degradation with attack penetration depth, through a rearranged form of Faraday’s law, are presented. An analytical model for cross-section analysis and shear strength prediction including the main effect due to rust formation is developed and verified against experimental data. Finally, a case study is added giving moment-curvature diagrams and moment-to-shear interaction diagrams to show the effects of different scenarios of natural corrosion increasing with time on beam elements. Ó 2017 Elsevier Ltd. All rights reserved. 1. Introduction Corrosion of reinforcing steel is one of the main causes of dete- rioration of reinforced concrete structures and affects both ulti- mate and serviceability conditions [1,2]. Its effects include cracking and spalling of the concrete cover, reduction and loss of bond between concrete and corroding reinforcement, and reduc- tion of the cross-sectional area of the reinforcing steel (longitudinal bars and stirrups). Reinforcing steel is normally passive in concrete due to high alkalinity of the concrete pore solution. However, penetration into the concrete of chlorides or carbonation destroys this inhibitive property of the concrete and leads to corrosion. Two types of cor- rosion of reinforcement can affect an R.C. structure: general and pitting. General corrosion affects a substantial area of longitudinal and transverse reinforcements with more or less uniform metal loss over the perimeter of the reinforcing bars. It also causes crack- ing and possibly spalling and delamination of the concrete cover and produces rust staining on the concrete surface. Pitting is a localized corrosion type, which concentrates on small areas of rein- forcement, causing spalling of the concrete cover. Nondestructive tests allows one to establish the presence of carbonation in concrete (carbonation test) and/or the presence of chlorides (chloride content) and to know whether the corrosion processes are ongoing. Also, nnondestructive testing allows one to estimate for general corrosion the reduction of the area of steel reinforcements through the gravimetric method and allows one to estimate the pit in the bar for chloride attack. Numerous experimental studies have investigated the effects of corrosion of materials such as on steel bars [3–4], steel-concrete bond [5–8], etc. There have also been studies at a structural level, relative for example to the flexural behavior of beams [9–13] and columns [10]. To reproduce the corrosion process in a laboratory, high inten- sities of current are used (ranging between 100 lA/cm 2 , used by [11] and 3000 lA/cm 2 , used by [5]); the duration of the tests is reduced to a few months or even a few days. In in situ structures, http://dx.doi.org/10.1016/j.conbuildmat.2017.05.125 0950-0618/Ó 2017 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: studioingcampione@libero.it (G. Campione). Construction and Building Materials 149 (2017) 395–405 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat