scholarly journals FLEXURAL CAPACITY OF CORRODED POST-TENSIONED CONCRETE BEAMS: LARGE SCALE TESTS AND NUMERICAL SIMULATION

2020 ◽  
Author(s):  
Antonino Recupero ◽  
Nino Spinella ◽  
Antonio Marì ◽  
Jesús Miguel Bairan
Keyword(s):  
Numerical Model ◽  
Bearing Capacity ◽  
Large Scale ◽  
Concrete Beams ◽  
Structural Response ◽  
Experimental Results ◽  
Analysis Model ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Post Tensioned

An experimental campaign on corroded post-tensioned concrete beams is being carried out at the University of Messina (Italy). The main goal of the research project is to study the influence of the tendon corrosion on the response behaviour of post-tensioned concrete beams subjected to a transversal load. In 2006, six beams were cast with a tendon placed at the centroid of the cross-section. Corrosion of the tendons was artificially induced in each specimen by injecting a chemical solution or an acid in some parts of the duct. The experimental results have showed how external causes, reproduced by artificial defects, can induce several critical issues, and undermine both the durability and the load bearing capacity of the beams. The load bearing capacity of the beam with defects was reduced until half of the one recorded for the specimen with not corroded tendon. In addition, a non-linear and time dependent analysis model, developed at UPC in Barcelona, was used to simulate the response of the tested beams, with the purpose of experimentally verifying the capacity of the model to capture the effects of corrosion along the time. A parametric study was performed with the numerical model to capture the influence of the degree of corrosion, (defined as the % loss of steel mass) on the serviceability response and on the ultimate capacity. By comparing the theoretical and the experimental results, the degree of corrosion was estimated and compared with that observed subsequently on the tested beams. Good correlation was obtained, thus allowing the numerical model to be used as a “virtual lab” to study the influence of several parameters on the structural response of corroded post-tensioned beams.

scholarly journals Axial Behaviour of Slender RC Circular Columns Strengthened with Circular CFST Jackets

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yiyan Lu ◽  
Tao Zhu ◽  
Shan Li ◽  
Weijie Li ◽  
Na Li
Keyword(s):  
Bearing Capacity ◽  
Ductile Failure ◽  
Steel Tube ◽  
Experimental Results ◽  
Strengthening Effect ◽  
Load Bearing Capacity ◽  
Rc Columns ◽  
Load Bearing ◽  
Cfst Columns ◽  
Material Utilization

This paper investigates the axial behavior of slender reinforced concrete (RC) columns strengthened with concrete filled steel tube (CFST) jacketing technique. It is realized by pouring self-compacting concrete (SCC) into the gap between inner original slender RC columns and outer steel tubes. Nine specimens were prepared and tested to failure under axial compression: a control specimen without strengthening and eight specimens with heights ranging between 1240 and 2140 mm strengthened with CFST jacketing. Experimental variables included four different length-to-diameter (L/D) ratios, three different diameter-to-thickness (D/t) ratios, and three different SCC strengths. The experimental results showed that the outer steel tube provided confinement to the SCC and original slender RC columns and thus effectively improved the behavior of slender RC columns. The failure mode of slender RC columns was changed from brittle failure (concrete peel-off) into ductile failure (global bending) after strengthening. And, the load-bearing capacity, material utilization, and ductility of slender RC columns were significantly enhanced. The strengthening effect of CFST jacketing decreased with the increase of L/D ratio and D/t ratio but showed little variation with higher SCC strength. An existing expression of load-bearing capacity for traditional CFST columns was extended to propose a formula for the load-bearing capacity of CFST jacketed columns, and the predictions showed good agreement with the experimental results.

Composite action in masonry walls under vertical in-plane loading: experimental results compared with predictions

2015 ◽  
Vol 42 (7) ◽  
pp. 449-462
Author(s):  
A.T. Vermeltfoort ◽  
D.R.W. Martens
Keyword(s):  
Bearing Capacity ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Compressive Force ◽  
Reinforced Concrete Beams ◽  
Elastic Behavior ◽  
Masonry Walls ◽  
Load Bearing Capacity ◽  
Cracking Behavior ◽  
Load Bearing

The results of five experimental test series on masonry walls supported by reinforced concrete beams or slabs are reported and compared to theoretical predictions of the load bearing capacity. The experiments were performed on deep masonry beams built with respectively calcium silicate and clay brick. Investigated parameters were: position of the supports, concrete beam-masonry interface, concrete beam stiffness, type of loading, and height of masonry wall and concrete beam. Based on literature, the method proposed by Davies and Ahmed as well as the method according to Eurocode 6 were used to estimate the load bearing capacity of the tested masonry walls supported by concrete beams. The method of Davies and Ahmed allows for the determination of the stresses and stress resultants in the masonry. The analysis shows that near the support an inclined compressive force acts at the bed joint, which means that a shear-compression stress state exists in the bed joint. Strength evaluation has been carried out using the Mann-Müller criterion that is adopted in Eurocode 6. Based on the test results, it may be concluded that both methods yield conservative values of the load bearing capacity, as could be expected. Before cracking a linear elastic behavior was observed, while after cracking a strut-and-tie model may be applied. To develop more accurate design models, it is recommended to investigate the post-cracking behavior in more detail.

The assessment of the level of local strengthening of pipe steel welded connections

2020 ◽  
Vol 10 (3) ◽  
pp. 252-262
Author(s):  
Marat Z. Yamilev ◽  
◽  
Egor А. Tigulev ◽  
Andrey А. Raspopov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Numerical Model ◽  
Bearing Capacity ◽  
Pipe Steel ◽  
Carbon Steels ◽  
Strengthening Effect ◽  
Low Carbon ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Welded Connection

The metal welding is accompanied by the formation of mechanically non-homogenous sections of welded connection. The pipeline welded connections also have sections, which are different in structure, chemical composition and mechanical properties. The mechanical inhomogeneity affects the load bearing capacity of welded connection and the structure as a whole, which is necessary to take into consideration when performing calculation analysis. So far, the specialists have established the dependencies in assessment of welded connection strength with various types of heterogeneous sections. However, this phenomenon has received little attention in case of pipeline welded connections made of low carbon steels. The existing theoretical models do not reflect actual anisotropy of mechanical properties of the welded connections and weld adjacent zone. The present study considers the model of welded connections of K56 pipe steels with various strength characteristics of sections of welded seam and weld adjacent zone, without defects. The assessment of mechanical inhomogeneity influence on load bearing capacity of welded connections was performed by applying the finite-element modelling of its stress-strain state. The developed numerical model helps to determine and optimize the criteria of testing of full scale samples of pipe steel welded connections with regards to the implementation of local strengthening effect. The research results demonstrated that the degree of contact strengthening in welded connections with X-shape grooving is higher than in welded connections with V-shaped grooving by 8 % at similar relative thickness of soft interlayer. The suggested numerical model can be applied for detailed calculations of pipelines with regards to the mechanical inhomogeneity of its welded connections.

scholarly journals LOAD BEARING CAPACITY OF THE GLASS RAILING ELEMENT

2016 ◽  
Vol 3 ◽  
pp. 65-70
Author(s):  
Elizabeta Šamec ◽  
Domagoj Damjanovic ◽  
Joško Krolo
Keyword(s):  
Mechanical Properties ◽  
Numerical Model ◽  
Structural Material ◽  
Bearing Capacity ◽  
Physical And Mechanical Properties ◽  
Laminated Glass ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Pedestrian Bridge ◽  
Numerical Testing

In this paper some basic physical and mechanical properties of glass as structural material are presented. This research is about specifically manufactured glass railing element that will be a part of a pedestrian bridge construction in Zagreb, Croatia. Load bearing capacity test of the glass railing element is conducted within the Faculty of Civil Engineering in Zagreb and obtained experimental results are discussed and compared to the ones provided by the numerical model. Taking into account the behaviour of laminated glass and results of experimental and numerical testing, glass railing element can be regarded as safe.

Residual load-bearing capacity of fire-exposed concrete beams reinforced with FRP bars

2021 ◽  
Author(s):  
Jan Prokeš ◽  
Iva Rozsypalová ◽  
František Girgle ◽  
Petr Daněk ◽  
Petr Štěpánek
Keyword(s):  
Bearing Capacity ◽  
Concrete Beams ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Frp Bars

Evaluation of Main Code Models for Predicting Flexural Load-Bearing Capacity against Intermediate Crack-Induced Debonding in FRP-Strengthened RC Beams

2011 ◽  
Vol 71-78 ◽  
pp. 1465-1468
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo ◽  
Xiao Yan Sun
Keyword(s):  
Bearing Capacity ◽  
Failure Modes ◽  
Experimental Results ◽  
Rc Beams ◽  
Test Results ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Accuracy Test ◽  
Comprehensive Comparison ◽  
Code Provisions

Intermediate crack-induced debonding is one of the most dominant failure modes in FRP-strengthened RC beams. Different code models and provisions have been proposed to predict intermediate crack-induced debonding failure. Out of all the existing code provisions and models, four typical ones are investigated in the current study. A comprehensive comparison among these code provisions and models is carried out in order to evaluate their performance and accuracy. Test results of flexural specimens with intermediate crack-induced debonding failure collected from the existing literature are used in the current comparison. The effectiveness and accuracy of each model have been evaluated based on these experimental results. It is shown that the current recommendations are inadequite to effectively mitigate intermediate crack-induced debonding in flexurally strengthened members.

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