scholarly journals Parametric Study on the Applicability of AASHTO LRFD for Simply Supported Reinforced Concrete Skewed Slab Bridges

2021 ◽  
Vol 6 (6) ◽  
pp. 88
Author(s):  
Lucía Moya ◽  
Eva O. L. Lantsoght
Keyword(s):  
Reinforced Concrete ◽  
Case Studies ◽  
Concrete Slab ◽  
Shear Forces ◽  
Reinforced Concrete Slab ◽  
Element Analysis ◽  
Analysis And Design ◽  
Simplified Procedures ◽  
Aashto Lrfd ◽  
Skew Angles

Simplified code provisions can be used for the analysis and design of straight slab bridges. However, several studies question the appropriateness of simplified procedures for skewed geometries. This paper provides practical insights to the designer regarding the effects of skewness in reinforced concrete slab bridges by evaluating how simplified and more refined analysis procedures impact the design magnitudes and resulting reinforcement layouts. The methods used for this study are analytical and numerical case studies. Eighty case study slab bridges with varying lengths, widths, and skew angles are subjected to the AASHTO HL-93 loading. Then, the governing moments and shear forces are determined using the AASHTO LRFD simplified procedures with hand calculations, and using linear finite element analysis (LFEA). Afterwards, the reinforcement is designed according to the AASHTO LRFD design provisions. From these case studies, it is found through the LFEA that increasing skew angles result in decreasing amounts of longitudinal reinforcement and increasing amounts of transverse flexural reinforcement. Comparing the reinforcement layouts using AASHTO LRFD-based hand calculations and LFEA, we find that using LFEA reduces the total weight of steel reinforcement needed. Moreover, as the skew increases, LFEA captures increased shear forces at the obtuse corner that AASHTO LRFD does not. In conclusion, it is preferable to design the reinforcement of skewed reinforced concrete slab bridges using LFEA instead of hand calculations based on AASHTO LRFD for cost reduction and safety in terms of shear resistance in the obtuse corners.

Microcomputer analysis of reinforced concrete slab systems

1993 ◽  
Vol 20 (4) ◽  
pp. 587-601 ◽  
Author(s):  
Pierre Léger ◽  
Patrick Paultre
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Structural Design ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Structural Behaviour ◽  
Reinforced Concrete Slab ◽  
Element Analysis ◽  
Equivalent Frame ◽  
Frame Method

Microcomputer finite element analysis of reinforced concrete slab systems can now be routinely performed to produce realistic numerical simulation of three-dimensional structural behaviour. However, an efficient use of this approach requires an automated integration of design and analysis procedures. Guidelines for proper finite element modelling of slab systems are first presented along with simple post-processing algorithms to perform automatically the design or verifications from the analytical results. Numerical applications on simple slab systems subjected to uniform and concentrated loads are then used to illustrate the relative performance between finite element analyses and the equivalent frame method. Key words: microcomputer, reinforced concrete slab, finite element method, structural design.

PARAPET STIFFNESS EFFECT ON LOAD CARRYING CAPACITY OF MULTI-LANE CONCRETE SLAB BRIDGES

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Sarah Jaber ◽  
Mounir Mabsout ◽  
Kassim Tarhini
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Bridge Deck ◽  
Concrete Slab ◽  
Load Carrying Capacity ◽  
Bending Moments ◽  
Reinforced Concrete Slab ◽  
Analysis And Design ◽  
Load Carrying ◽  
Longitudinal Bending

Bridge specifications do not consider the effect of parapet stiffness in the analysis and design of reinforced concrete slab bridges. This paper performs a parametric investigation using finite element analysis (FEA) to study the effects of parapet stiffness on live load-carrying capacity of two-span, three-and four-lane concrete slab bridges. This study analyzed 96 highway bridge cases with varied parameters such as span-length, bridge width, and parapet stiffness within practical ranges. Reinforced concrete parapets or railings, built integrally with the bridge deck, were placed on one and/or both sides of bridge deck. The longitudinal bending moments calculated using the FEA results were compared with reference bridge cases without parapets, as well as AASHTO Standard and LRFD specifications. The FEA results presented in this paper showed that the presence of concrete parapets reduces the negative bending moments by 15% to 60% and the positive bending moments by 10% to 45%. The reduction in longitudinal bending moments can mean an increase in the load-carrying capacity of such bridges depending on the parapet stiffness. This investigation can assist engineers in modeling the actual bridge geometry more accurately for estimating the load-carrying capacity of existing concrete bridges. Hence, new bridges can be designed by considering the presence of concrete parapets. Parapets can be used as an alternative for strengthening existing one and two-span reinforced concrete slab bridges.

scholarly journals Assessment of reinforced concrete slab of historical structures by the yield-line method

2021 ◽  
Author(s):  
Rayan Mahrouseh ◽  
Zoltán Orbán
Keyword(s):  
Reinforced Concrete ◽  
Boundary Conditions ◽  
Bearing Capacity ◽  
Concrete Slab ◽  
Reinforced Concrete Slab ◽  
Element Analysis ◽  
Yield Line ◽  
Historical Structures ◽  
Reinforced Concrete Slabs ◽  
First Case

AbstractThe study demonstrates and evaluates an approach in the structural analysis phase when assessing reinforced concrete slabs.Due to different values of a parameter in the tests’ results, 10 models was crated for the first case study and 4 models for the second one.In order to compare the results in terms of the flexural bearing capacity, the slabs were analyzed by using elastic finite element analysis and yield-line analysis.Comparing the results shows that minor modification in the parameters associated with bearing capacity and the boundary conditions can affect the adequacy factor considerably, while the parameters those relate to boundary conditions affect the distribution of the yield lines.

scholarly journals Finite element analysis of flexural behavior of textile reinforced concrete slab

2021 ◽  
Vol 261 ◽  
pp. 02042
Author(s):  
Mingqiu Xu ◽  
Jianhua Shao ◽  
Baijian Tang ◽  
Hongming Li
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Element Model ◽  
Concrete Slab ◽  
Element Model ◽  
Flexural Behavior ◽  
Textile Reinforced Concrete ◽  
Reinforced Concrete Slab ◽  
Element Analysis ◽  
Bending Load

Order to investigate the failure effect of textile reinforced concrete (TRC) plate under bending load, the corresponding finite element model is established. By comparing the numerical simulation results with the experimental results, the rationality and feasibility of the finite element model are verified, and then the crack extension of TRC and the ultimate strain of carbon textile are analyzed. The failure mode of the slab under bending load is obtained, and it is found that the carbon textile concrete slab has better reinforcement effect, which greatly improves the safety performance of concrete members.

scholarly journals Numerical Modelling of One-Way Reinforced Concrete Slab in FireTaking Into Account of Spalling

2021 ◽  
Vol 7 (3) ◽  
pp. 477-487
Author(s):  
Guergah Cherif ◽  
Dimia Mohamed Salah ◽  
Benmarce Abdelaziz
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Mechanical Response ◽  
Concrete Slab ◽  
Fire Exposure ◽  
Reinforced Concrete Slab ◽  
Element Analysis ◽  
Finite Element Software ◽  
Rc Slabs

This paper presents a study of the behaviour of Reinforced Concrete (RC) slabs subjected to severe hydrocarbon fire exposure. In which the spalling phenomena of concrete is to be considered. The hydrocarbon curve is applicable where small petroleum fires might occur, i.e. car fuel tanks, petrol or oil tankers, certain petro-chemical facilities, tunnels, parking structures, etc. Spalling is included using a simplified approach where elements with temperatures higher than 400 °C are assumed to occur and the corresponding thermo-mechanical response of RC slabs is evaluated. The nonlinear finite element software SAFIR has been used to perform a numerical analysis of the spalling risk, by removing layers of concrete covering when a set of spalling criteria is checked. The numerical results obtained by finite element analysis of the temperature distribution within the slab and mid-span deflection were compared with published experimental data. Predictions from the numerical model show a good agreement with the experimental data throughout the entire fire exposure to the hydrocarbon fire. This shows that this approach (layering procedure) is very useful in predicting the behaviour of concrete spalling cases. Doi: 10.28991/cej-2021-03091667 Full Text: PDF

Experimental–theoretical investigation for damage assessment of a reinforced concrete slab under consecutive explosions based on single-degree-of-freedom model

2020 ◽  
pp. 204141962093806
Author(s):  
Seung-Hun Sung ◽  
Hun Ji ◽  
Jinwung Chong
Keyword(s):  
Reinforced Concrete ◽  
Damage Assessment ◽  
Concrete Slab ◽  
Permanent Deformation ◽  
Degree Of Freedom ◽  
Dynamic Responses ◽  
Reinforced Concrete Slab ◽  
Element Analysis ◽  
Single Degree Of Freedom ◽  
Single Degree

This study performed damage assessment of a reinforced concrete slab subjected to consecutive explosions. To this end, the resistance functions were updated to account for the permanent displacement calculated in the previous step to capture the response of the reinforced concrete slab of the current explosion. In other words, the permanent deformation should be basically evaluated according to the prior explosion. Next, the revised resistance function should be calculated according to damage level. Third, the maximum dynamic responses should be estimated based on the modified single-degree-of-freedom model. Finally, cumulative damages can be evaluated based on the sum of the permanent deformation and the maximum dynamic responses. In order to confirm a feasibility of the proposed single-degree-of-freedom model, a comparative study with the finite element analysis results is carried out under the identical consecutive explosions. Prior to performing the comparative study, the computational model of the target structure is calibrated based on small-scale experimental data to carry out more reliable finite element analysis.

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