Mechanical in-plane behaviour of masonry walls reinforced by composite materials: Experimental and analytical approaches

2017 ◽  
Vol 51 (30) ◽  
pp. 4231-4249 ◽  
Author(s):  
L Bui ◽  
N Reboul ◽  
A Si Larbi ◽  
E Ferrier
Keyword(s):  
Reinforced Concrete ◽  
Composite Materials ◽  
Experimental Tests ◽  
Analytical Models ◽  
Masonry Walls ◽  
Masonry Structures ◽  
Textile Reinforced Concrete ◽  
Reinforced Polymers ◽  
Externally Bonded ◽  
Analytical Approaches

Masonry is a traditional building system in most countries of the world, including France. However, in recent decades, earthquakes have caused significant damage to masonry structures. The possibility of using textile-reinforced concrete or fibre-reinforced polymers to strengthen masonry structures has been recently assessed. This article addresses the effectiveness of externally bonded composite materials, particularly those based on newly developed cementitious matrices, to strengthen masonry structures. Experimental tests were performed in a previous study on six masonry walls, five of which were strengthened on both sides with either textile-reinforced concrete or fibre-reinforced polymers. This experimental campaign has been supplemented to determine the mechanical properties of the materials involved in design models, and it is used to check the potential of analytical models to predict lateral strength. This study identifies the interests and the restrictions governing the use of traditional empirical design approaches (employed for fibre-reinforced polymer-strengthened walls) when next-generation textile-reinforced concrete composites are used as strengthening materials. Adjustments taking into account the specificities of textile-reinforced concrete behaviour have been introduced, and their impact on the relevance of the models has been quantified.

scholarly journals Mechanical Behaviour of TRC Composites: Experimental and Analytical Approaches

2019 ◽  
Vol 9 (7) ◽  
pp. 1492 ◽  
Author(s):  
Marco Carlo Rampini ◽  
Giulio Zani ◽  
Matteo Colombo ◽  
Marco di Prisco
Keyword(s):  
Reinforced Concrete ◽  
Mechanical Behaviour ◽  
High Performance ◽  
Tensile Tests ◽  
Seismic Retrofitting ◽  
Analytical Models ◽  
Uniaxial Tensile ◽  
Textile Reinforced Concrete ◽  
Predictive Approaches ◽  
Analytical Approaches

Textile reinforced concrete (TRC) is a promising high-performance material that has been employed with success in new constructions, as well as a strengthening layer of existing structural components. In this work, we document the optimisation procedure of textile-based composites for new construction and for the seismic retrofitting of under-reinforced concrete elements and masonry buildings. The study, aimed at maximising the material performances avoiding waste of economic resources, was addressed by means of a series of uniaxial tensile tests conducted on a wide set of alkali-resistant (AR) glass fabrics and TRCs. The samples differed in terms of cement-based matrices, embedded textiles and addition of dispersed microfibers. The results highlight the effects of fabric characteristics and introduction of short fibres on the mechanical behaviour, proposing novel comparison parameters based upon the load bearing capacity and the deformation response of the composites. The application of simplified analytical models borrowed from the literature finally revealed the limitations of the available predictive approaches, suggesting future lines of investigation.

scholarly journals Comparison of Analytical Approaches Predicting the Compressive Strength of Fibre Reinforced Polymers

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2517 ◽  
Author(s):  
Christian Leopold ◽  
Sergej Harder ◽  
Timo Philipkowski ◽  
Wilfried Liebig ◽  
Bodo Fiedler
Keyword(s):  
Compressive Strength ◽  
Prediction Accuracy ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Experimental Results ◽  
Analytical Models ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Analytical Approaches

Common analytical models to predict the unidirectional compressive strength of fibre reinforced polymers are analysed in terms of their accuracy. Several tests were performed to determine parameters for the models and the compressive strength of carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP). The analytical models are validated for composites with glass and carbon fibres by using the same epoxy matrix system in order to examine whether different fibre types are taken into account. The variation in fibre diameter is smaller for CFRP. The experimental results show that CFRP has about 50% higher compressive strength than GFRP. The models exhibit significantly different results. In general, the analytical models are more precise for CFRP. Only one fibre kinking model’s prediction is in good agreement with the experimental results. This is in contrast to previous findings, where a combined modes model achieves the best prediction accuracy. However, in the original form, the combined modes model is not able to predict the compressive strength for GFRP and was adapted to address this issue. The fibre volume fraction is found to determine the dominating failure mechanisms under compression and thus has a high influence on the prediction accuracy of the various models.

Seismic strengthening of masonry walls using bamboo components

2019 ◽  
Vol 22 (14) ◽  
pp. 2982-2997 ◽  
Author(s):  
Qingfeng Xu ◽  
Xi Chen ◽  
Jian-Fei Chen ◽  
Kent A Harries ◽  
Lingzhu Chen ◽  
...  
Keyword(s):  
Construction Industry ◽  
Cement Mortar ◽  
Masonry Walls ◽  
Masonry Structures ◽  
Limit States ◽  
Green Material ◽  
Remote Areas ◽  
Externally Bonded ◽  
Reinforced Cement ◽  
Energy Dissipation Capacity

Bamboo is a sustainable green material and has been gradually applied in the construction industry; however, little research on strengthening masonry structures with bamboo has been carried out. In this article, strengthening methods using bamboo were developed including bamboo grid reinforced cement mortar layer, externally bonded bamboo mats, additional confining horizontal bamboo reinforced concrete band beams, and bamboo strips placed in mortar joints. Ten masonry walls were designed including two reference walls. Experimental results showed that all the strengthening methods can improve certain aspects of the seismic performance of masonry walls. The shear strength, deformability, and energy dissipation capacity of masonry walls strengthened with bamboo grid reinforced cement mortar and externally bonded bamboo mats were the most improved. The limit states of tested walls were discussed. Strengthened masonry structures with bamboo components are promising methods and can be used especially in remote areas.

scholarly journals Investigation of crack prediction in reinforced concrete liquid containing structures

2021 ◽  
Author(s):  
Armin Zyarishalmani
Keyword(s):  
Reinforced Concrete ◽  
Prediction Models ◽  
Theoretical Calculations ◽  
Experimental Tests ◽  
Fiber Reinforced Polymers ◽  
Water Leakage ◽  
Positive Role ◽  
Reinforced Polymers ◽  
Cracking Behavior ◽  
Advantages And Disadvantages

Cracking in liquid containing structures, if it is not properly controlled, can have serious detrimental effects on the overall system functionality. Having a consistent knowledge of concrete cracking characteristics is essential for a designer to ensure serviceability requirements of the structure. In spite of several proposed crack prediction models that have been used as the base for design codes, still a lack of certainty can be clearly felt in predicting cracking behavior of reinforced concrete. This is due to the fact that cracking is a very complex phenomenon in which numerous factors are involved, and it is always too cumbersome to take the effects of all these influential aspects into account. In order to acquire more insight into this issue, a comprehensive attempt has been made both experimentally and theoretically here in this study. This research is primarily dealing with cracks that develop under monotonic increasing load which is the main cause for the formation of wide cracks among other causes such as shrinkage or temperature. In this regard, several laboratory tests were conducted on a one meter wide strip of a tank wall. These experiments covered a range of loading configuration that would enable various combinations of stresses across the reinforced concrete section. Cracking behavior and water tightness of the slab were closely monitored and reported. Fiber reinforced polymers were shown to be a suitable means of remediation in reducing water leakage or recovering structural strength. A positive role of concrete autogenous healing on water leakage was investigated during the practical test. A comparison is made between experimental results and several recent well-known crack prediction models, through which their advantages and disadvantages are revealed and discussed. Several finite element models (FEM) have been successfully built with the aid of computer program ABAQUS/6.5 to capture the post-failure stress/strain condition in concrete and reinforcement, the results of which are perfectly matching with those obtained from experimental tests and theoretical calculations.

scholarly journals Debonding-Related Strain Limits for Externally Bonded FRP Sheets in Flexurally Strengthened Reinforced Concrete Beams

2013 ◽  
Vol 7 (1) ◽  
pp. 58-67 ◽  
Author(s):  
Guibing Li ◽  
Aihui Zhang ◽  
Yugang Guo
Keyword(s):  
Reinforced Concrete ◽  
Tensile Strain ◽  
Concrete Beams ◽  
Experimental Tests ◽  
Critical Issue ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Externally Bonded ◽  
Strengthening Technique ◽  
Code Provisions

Debonding problems of externally bonded fiber reinforced polymer (FRP) sheets in flexurally FRP-strengthened reinforced concrete (RC) beams have been a concern and a research challenge since their application of this strengthening technique. Intermediate crack induced debonding is the most common failure mode which is that the debonding initiates at the critical flexural-shear or flexural cracks and propagates towards the direction of moment decrease. To mitigate debonding failure, most Codes and proposed models take the method by limiting the allowable tensile strain in FRP laminates. This paper presents experimental tests of concrete beams flexurally strengthened with externally bonded CFRP sheets to investigate debonding initiation and tensile strain of FRP laminates. The allowable tensile strain of FRP sheets in flexurally FRP-strengthened RC beams proposed by prevalent Code provisions and models was assessed based on the data obtained from experimental programs. It has beenshown that the allowable tensile strains provided by these provisions and models have a great difference with that of experimental results and exhibit a high level of dispersion. Furthermore, the FRP laminates of most tested RC beams were debonded before reaching the proposed allowable tensile strain. The Code provisions and models are inadequate to effectively prevent intermediate crack induced debonding failure in flexurally FRP-strengthened RC members. This is known to be a critical issue in engineering design and application of RC beams flexurally strengthened by FRP sheets.

Criteria for the Repair of Damage to Masonry Walls of Buildings Affected by Earthquakes Using Composite Materials with Inorganic Matrix

2017 ◽  
Vol 747 ◽  
pp. 670-677 ◽  
Author(s):  
Antonio La Tegola ◽  
Walter Mera
Keyword(s):  
Composite Materials ◽  
Energy Dissipation ◽  
Organic Matrix ◽  
Masonry Walls ◽  
Masonry Structures ◽  
Cementitious Composite ◽  
Brittle Behavior ◽  
Frequent Use ◽  
Metallic Mesh ◽  
Inorganic Matrix

After the inspections to the damage caused by the last earthquake in Ecuador, and considering the construction typologies of reinforced concrete buildings in Guayaquil and Manta (Ecuador), in order to rebuild or repair the masonry walls we must resort to composite materials with inorganic matrix (cementitious). Composite materials in FRP with an organic matrix (epoxy) are not appropriate because, with an increase of strength they have a brittle behavior, therefore without possibility of energy dissipation not having the ductility provided by a metallic mesh or cobalt-metallic mesh, which have the advantage of using it with a cementitious matrix of frequent use in the current technology. Since the photographic records and the design of those masonry structures allow determining in detail the dynamics of the damage, it is possible to add to the theoretical analysis an experimental verification on the behavior of masonry walls with reinforced plastering with FRP or with metallic mesh with inorganic matrix under seismic actions.

scholarly journals Analysis of confined masonry with Strut and Tie models

2020 ◽  
Vol 323 ◽  
pp. 02002
Author(s):  
Łukasz Drobiec ◽  
Wojciech Mazur ◽  
Tomasz Rybarczyk
Keyword(s):  
Reinforced Concrete ◽  
Full Scale ◽  
Masonry Walls ◽  
Reinforced Concrete Structures ◽  
Masonry Structures ◽  
Test Results ◽  
Confined Masonry ◽  
Good Compliance ◽  
Strut And Tie ◽  
Calculation Results

Strut & Tie (S-T) models are used quite commonly for the analysis of reinforced concrete structures and in the calculation of masonry structures. Creating the S-T model of the confined masonry is slightly different from models of reinforced concrete or models of classic masonry structures. These models should take into account different stiffness of concrete and masonry. This article proposes a Strut & Tie model for the analysis of confined masonry. The results of calculations were compared with the results of tests of full scale masonry walls with and without opening. Good compliance of the calculation results of S-T models with the test results was obtained.

scholarly journals Investigation of crack prediction in reinforced concrete liquid containing structures

2021 ◽  
Author(s):  
Armin Zyarishalmani
Keyword(s):  
Reinforced Concrete ◽  
Prediction Models ◽  
Theoretical Calculations ◽  
Experimental Tests ◽  
Fiber Reinforced Polymers ◽  
Water Leakage ◽  
Positive Role ◽  
Reinforced Polymers ◽  
Cracking Behavior ◽  
Advantages And Disadvantages

Cracking in liquid containing structures, if it is not properly controlled, can have serious detrimental effects on the overall system functionality. Having a consistent knowledge of concrete cracking characteristics is essential for a designer to ensure serviceability requirements of the structure. In spite of several proposed crack prediction models that have been used as the base for design codes, still a lack of certainty can be clearly felt in predicting cracking behavior of reinforced concrete. This is due to the fact that cracking is a very complex phenomenon in which numerous factors are involved, and it is always too cumbersome to take the effects of all these influential aspects into account. In order to acquire more insight into this issue, a comprehensive attempt has been made both experimentally and theoretically here in this study. This research is primarily dealing with cracks that develop under monotonic increasing load which is the main cause for the formation of wide cracks among other causes such as shrinkage or temperature. In this regard, several laboratory tests were conducted on a one meter wide strip of a tank wall. These experiments covered a range of loading configuration that would enable various combinations of stresses across the reinforced concrete section. Cracking behavior and water tightness of the slab were closely monitored and reported. Fiber reinforced polymers were shown to be a suitable means of remediation in reducing water leakage or recovering structural strength. A positive role of concrete autogenous healing on water leakage was investigated during the practical test. A comparison is made between experimental results and several recent well-known crack prediction models, through which their advantages and disadvantages are revealed and discussed. Several finite element models (FEM) have been successfully built with the aid of computer program ABAQUS/6.5 to capture the post-failure stress/strain condition in concrete and reinforcement, the results of which are perfectly matching with those obtained from experimental tests and theoretical calculations.

Sign in / Sign up

Export Citation Format

Share Document