Experimental investigation and numerical simulation of tension stiffening effect in reinforced concrete
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Journal Title
Journal ISSN
Volume Title
Insinööritieteiden korkeakoulu |
Master's thesis
Authors
Date
2017-10-30
Department
Major/Subject
Structural Engineering
Mcode
ENG3039
Degree programme
Master's Programme in Structural Engineering
Language
en
Pages
6+72
Series
Abstract
In strength design calculation of reinforced concrete member, the tensile strength is generally neglected and all the tensile strength is assumed to be carried by the steel reinforcement. In reality however, the concrete between the cracks still continues to carry tensile stresses between the cracks due to the bond between steel and concrete. This additional stiffness of the concrete in the tensile region even after cracking is known as tension Stiffening. It is important to understand the tension stiffening behavior to accurately assess the serviceability requirements of reinforced concrete members and also their long-term deflection behavior. The aim of the experimental work was to devise a simple testing setup that would allow to describe and quantify the tension stiffening behavior in reinforce concrete in direct tension. Three different types of reinforced concrete specimens were tested in direct tension to quantify their short-term tension stiffening response and then compared with a previously proposed tension stiffening model. It was found that the experimental program was able to demonstrate the tension stiffening behavior quite well, however bending of the specimen was observed in most cases. Comparison with previously developed tension stiffening model showed that the models are accurate in predicting the tension stiffening response for normal members, however they underestimated the tension stiffening in members that have more distributed reinforcement. A finite element analysis was also performed to model the bond slip mechanism between steel and concrete using the ABAQUS software. Cohesive surface interaction module was used to implement the FIB Bond slip model. The finite element model provided a good approximation of the actual strains in the steel bar, however, it was observed that the accuracy of results was greatly dependent on the chosen value of interface stiffness (K).Description
Supervisor
Puttonen, JariThesis advisor
Puttonen, JariKeywords
reinforced concrete, tension stiffening, cracking, finite element analysis, ABAQUS