Experimental investigation on long-term behavior of prestressed concrete beams under coupled effect of sustained load and corrosion

Abstract

Prestressed concrete beams are widely used in construction, while they may be attacked by the corrosion medium during the service. Past research works show that coupled effect of high stress and corrosion can significantly deteriorate the performance of prestressed concrete structures. This article presents an experimental investigation on long-term behavior of prestressed concrete beams under the coupled effect of sustained load and corrosion. During the accelerated corrosion process, six prestressed concrete beams were subjected to different levels of sustained loads, and time-dependent prestress loss and concrete stains were recorded and analyzed. It is observed that the local corrosion (i.e. pitting corrosion) of the steel strands was significantly affected by the sustained load level, and the coupled effect led to more serious damage on the beams than individual sustained load or corrosion. Bending loads were finally applied to investigate the influence of corrosion on flexural capacities of these beams. It was found that the flexural capacities and failure mode of the beams were significantly influenced by corrosion. Meanwhile, the corrosion has more significant effect on tension strength of strands rather than bond strength.

Residual Flexural Capacity of Corroded Prestressed Reinforced Concrete Beams

“…The studies are grouped in order to clearly distinguish the members subjected to different corrosion processes (natural or accelerated). Among them, four articles [29][30][31][32] dealt with the behavior of beams extracted by a decommissioned bridge (DB_N); three works [33][34][35] investigated the performance of beams with reduced dimensions with respect to the previous ones and subjected to a naturally corrosive environment (B_N); eleven papers [36][37][38][39][40][41][42][43][44][45][46][47] experimentally tested the flexural performance of PRC beams damaged by artificial corrosion (B_A). • ∆R max *** ∼ = 50% for the beam with some wire cross-section loss up to 75%.…”

“…Yang et al [42], unlike other experimental groups, performed the artificial corrosion of PRC beams during the application of a high bending moment. In total, six beam specimens were fabricated and corroded using an accelerated corrosion procedure.…”

“…More recently, the Polcevera Viaduct in Genoa, which was in service for over 50 years, collapsed, likely due to the combined effects of corrosion and fatigue [23][24][25]. Although scientific efforts are being devoted to the assessment of the residual structural performance of prestressed RC members damaged by corrosion [26][27][28], few experimental studies have been conducted to explore the flexural behavior of corroded pretensioned reinforced concrete (PRC) beams [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47]. The beams realized with the pretensioning technique, where the strands are adherent to the concrete, respond differently to the corrosion phenomenon with respect to the case of beams realized with the post-tensioning technique [38,48].…”

“…µ was progressively reduced by increasing the corrosion degradation. Concerning the artificially corroded PRC beams, nine papers [36][37][38][39][40][41][42][43][44][45] experimentally investigated the flexural performance decay under monotonic loads (B_A_M); with the aim of investigating the beneficial effects of retrofitting intervention by means of composite materials, two works [39,41] also address the issue of the structural response of corroded PRC beams (RB_A); only one article [39] deals with both monotonic and cyclic flexure behavior (B_A_C); two papers [46,47] investigate the fatigue performance of corroded PRC beams (B_A_F). In the following, the prominent key findings of this research are summarized with specific reference to the results obtained for the flexural performance of corroded beams.…”

An Innovative Smart Concrete Anchorage with Self-Stress Sensing Capacity of Prestressing Stress of PS Tendon

“…These collapses have resulted in casualties and substantial social damage. One of the main causes of the early deterioration of concrete infrastructure is the failure of the prestressing (PS) tendon because of corrosion [ 1 , 2 , 3 , 4 , 5 , 6 ]. Furthermore, it is still difficult to measure the effective prestressing stress of the PS tendon in prestressed concrete (PSC) structures during their service time, even though the stress of the PS tendon is one of the critical parameters governing the global behavior of PSC structures.…”