Large-scale fatigue tests on prestressed concrete beams

Author(s):  
Dennis Birkner ◽  
Steffen Marx

<p>For a better estimation of the fatigue lifetime of real structures, tests on large-scale beam specimens are more suitable than on common cylindrical specimens, since effects like local stiffness changes and stress redistributions can be reproduced more realistically. This article presents an experimental setup for large-scale concrete beams subjected to fatigue loading. Additionally, the fatigue tests are simulated with a numerical model. The results of the numerical analysis show a successively increasing damage propagating from the edge into the inner part of the cross-section in the mid span with increasing number of cycles. This results in stress redistributions which extend the lifetime of the structure. The evaluation of the experimental investigation on the first beam specimen shows a larger stiffness degradation at the upper edge than in the centre of the cross-section as well as increasing strains at this location. This matches the expected effects from the numerical analysis.</p>


2018 ◽  
Vol 11 (2) ◽  
pp. 307-330
Author(s):  
M. W. MOURA ◽  
M. V. REAL ◽  
D. D. LORIGGIO

Abstract In this work a computational model is presented to evaluate the ultimate bending moment capacity of the cross section of reinforced and prestressed concrete beams. The computational routines follow the requirements of NBR 6118: 2014. This model is validated by comparing the results obtained with forty-one experimental tests found in the international bibliography. It is shown that the model is very simple, fast and reaches results very close to the experimental ones, with percentage difference of the order of 5%. This tool proved to be a great ally in the structural analysis of reinforced and prestressed concrete elements, besides it is a simplified alternative to obtain the cross section ultimate bending moment.



2012 ◽  
Vol 174-177 ◽  
pp. 1463-1470
Author(s):  
Ke Li ◽  
Xin Ling Wang ◽  
Shuang Yin Cao

500 MPa level hot-rolled ribbed bars of fine grains (HRBF500) is a successfully developed new-type steel in Chain. The fatigue behavior of partially prestressed reinforced concrete (RC) beams with HRBF500 bars was investigated in fatigue tests of pre-tensioned T-beams. The beams are simply supported with the same overall dimensions, and the main parameter in the study is prestress degree and longitudinal steel ratio. Four beams were constructed and tested under constant-amplitude fatigue loading. All beams are initially cracked before the application of repeated loading. The stress evolution of HRBF500 bars and prestressed strands, the information about crack growth and the deflection developments of test beams were presented. The main factors that affect the fatigue properties of prestressed concrete test beams were fully discussed. Test results indicate that, the prestressed concrete beams reinforced with appropriate amount of HRBF500 bars and reasonable prestressing configurations can survive 2.5 millions cycles of constant-amplitude fatigue loading using an upper-bound fatigue load producing tensile stress of less than 150 MPa in HRBF500 bars. The results provide important guidance for the fatigue design of prestressed concrete beams with HRBF500 bars.



PCI Journal ◽  
1994 ◽  
Vol 39 (6) ◽  
pp. 70-88
Author(s):  
Bruce W. Russell ◽  
Ned H. Burns


2021 ◽  
Author(s):  
Eva O. L. Lantsoght ◽  
Cor van der Veen ◽  
Rutger Koekkoek ◽  
Henk Sliedrecht

<p>In The Netherlands, existing slab-between-girder bridges with prestressed girders and thin transversely prestressed concrete decks require assessment. The punching capacity was studied in a previous series of experiments, showing a higher capacity thanks to compressive membrane action in the deck. Then, concerns were raised with regard to fatigue loading. To address this, two series of large-scale experiments were carried out, varying the number of loads (single wheel print versus double wheel print), the loading sequence (constant amplitude versus variable amplitude, and different loading sequences for variable amplitude), and the distance between the prestressing ducts. An S-N curve is developed for the assessment of slab-between-girder bridges. The experiments showed that compressive membrane actions enhances the capacity of thin transversely prestressed decks subjected to fatigue loading.</p>



2020 ◽  
Vol 223 ◽  
pp. 111187
Author(s):  
Amilton Rodrigues da Silva ◽  
João Paulo de Souza Rosa


2019 ◽  
Vol 23 (7) ◽  
pp. 1290-1304
Author(s):  
Yang Yang ◽  
Ze-Yang Sun ◽  
Gang Wu ◽  
Da-Fu Cao ◽  
Zhi-Qin Zhang

This study presents a design method for hybrid fiber-reinforced-polymer-steel-reinforced concrete beams by an optimized analysis of the cross section. First, the relationships among the energy consumption, the bearing capacity, and the reinforcement ratio are analyzed; then, the parameters of the cross section are determined. Comparisons between the available theoretical and experimental results show that the designed hybrid fiber-reinforced-polymer-steel-reinforced concrete beams with a low area ratio between the fiber-reinforced polymer and the steel reinforcement could meet the required carrying capacity and exhibited high ductility.



2016 ◽  
Vol 821 ◽  
pp. 3-9 ◽  
Author(s):  
Tereza Brožová ◽  
Tomáš Luks ◽  
Ilya Astrouski ◽  
Miroslav Raudenský

This article deals with fatigue tests of polymeric hollow fibre heat transfer surfaces. The hollow fibres have an outer diameter between 0.5-0.8 mm and wall thickness 10 % of the outer diameter. These plastic heat transfer surfaces have some limitations but also many benefits. One of the limitations is the durability of plastic under fatigue loading. The heat transfer surfaces were subjected to pulsating pressure loads under different conditions (level of pressure, ambient temperature, number of cycles). Firstly, only an internal hydraulic pulsating load was applied and the behaviour of the hollow fibres was observed, focusing especially on the presence of leaks, ruptures, etc.Then, other conditions of operations were added. The heat transfer surfaces were immersed in a hot bath and loaded by internal pulsating pressure and high temperature simultaneously. Testing under different temperatures is important because the temperature significantly affects the material properties. The presence of leaks, ruptures and other possible damage was monitored as with previous tests.



Author(s):  
Hideaki Kasano ◽  
Osamu Hasegawa ◽  
Chiaki Miyasaka

Advanced fiber reinforced composite materials offer substantial advantages over metallic materials for the structural applications subjected to fatigue loading. With the increasing use of these composites, it is required to understand their mechanical response to cyclic loading [1–4]. Our major concern in this work is to macroscopically evaluate the damage development in composites during fatigue loading. For this purpose, we examine what effect the fatigue damage may have on the material properties and how they can be related mathematically to each other. In general, as the damage initiates in composite materials and grows during cyclic loading, material properties such as modulus, residual strength and strain would vary and, in many cases, they may be significantly reduced because of the progressive accumulation of cracks. Therefore, the damage can be characterized by the change in material properties, which is expected to be available for non-destructive evaluation of the fatigue damage development in composites. Here, the tensiontension fatigue tests are firstly conducted on the plain woven fabric carbon fiber composites for different loading levels. In the fatigue tests, the dynamic elastic moduli are measured on real-time, which will decrease with an increasing number of cycles due to the degradation of stiffness. Then, the damage fimction presenting the damage development during fatigue loading is determined from the dynamic elastic moduli thus obtained, from which the damage function is formulated in terms of a number of cycles and an applied loading level. Finally, the damage function is shown to be applied for predicting the remaining fifetime of the CFRP composites subjected to two-stress level fatigue loading.



2002 ◽  
pp. 107-119 ◽  
Author(s):  
Bui Khac DIEP ◽  
Hidetaka UMEHARA ◽  
Tada-aki TANABE


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