Review of Polymer Coatings Used for Blast Strengthening of Reinforced Concrete and Masonry Structures

2018 ◽  
pp. 713-719 ◽  
Author(s):  
Girum S. Urgessa ◽  
Mohammadjavad Esfandiari
Keyword(s):  
Reinforced Concrete ◽  
Polymer Coatings ◽  
Masonry Structures

Design and Construction of Hybrid Concrete-Masonry Structures Informed by Cyclic Tests

2016 ◽  
Vol 32 (4) ◽  
pp. 2337-2355 ◽  
Author(s):  
Laura Redmond ◽  
Lawrence Kahn ◽  
Reginald DesRoches
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
Masonry Structures ◽  
Cyclic Tests ◽  
Reinforced Concrete Frame ◽  
Masonry Infill ◽  
Concrete Frame ◽  
Concrete Masonry ◽  
Dowel Connections ◽  
Design And Construction

Reinforced concrete buildings with masonry infill are vulnerable in earthquakes primarily because the masonry walls often fail due to out-of-plane forces and can trigger soft-story collapses. In order to prevent these failures, many engineers in the Caribbean have partially reinforced the infill walls and connected them to the reinforced concrete frame. This forms a hybrid concrete-masonry structure. Hybrid concrete-masonry structures have the potential to improve the seismic performance of many structures across the globe, as they are an easy adaptation from traditional unreinforced masonry infill. However, there is little codified guidance for this type of structure, and the influence of the masonry infill and dowel connections on the in-plane behavior of the frame is often neglected. This paper summarizes the current design and construction practices for hybrid concrete-masonry structures and assesses their seismic performance via cyclic tests on full scale test specimens. Based on the results of the experiment, a method is proposed to account for the dowel connections and the partially reinforced infill when designing hybrid concrete-masonry structures in earthquake zones.

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 Structural Behaviors of Reinforced Concrete Piers Rehabilitated with FRP Wraps

2017 ◽  
Vol 2017 ◽  
pp. 1-14
Author(s):  
Junsuk Kang
Keyword(s):  
Reinforced Concrete ◽  
Fiber Reinforced Polymer ◽  
Design Parameters ◽  
Masonry Structures ◽  
Finite Element Analyses ◽  
Maintenance Costs ◽  
Existing Structures ◽  
Reinforced Polymer ◽  
Complex Structural ◽  
Structural Behaviors

The use of fiber-reinforced polymer (FRP) wraps to retrofit and strengthen existing structures such as reinforced concrete piers is becoming popular due to the higher tensile strength, durability, and flexibility gained and the method’s ease of handling and low installation and maintenance costs. As yet, however, few guidelines have been developed for determining the optimum thicknesses of the FRP wraps applied to external surfaces of concrete or masonry structures. In this study, nonlinear pushover finite element analyses were utilized to analyze the complex structural behaviors of FRP-wrapped reinforced rectangular piers. Design parameters such as pier section sizes, pier heights, pier cap lengths, compressive strengths of concrete, and the thicknesses of the FRP wraps used were thoroughly tested under incremental lateral and vertical loads. The results provide useful guidelines for analyzing and designing appropriate FRP wraps for existing concrete piers.

scholarly journals Elastomeric Polymers for Retrofitting of Reinforced Concrete Structures against the Explosive Effects of Blast

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
S. N. Raman ◽  
T. Ngo ◽  
P. Mendis ◽  
T. Pham
Keyword(s):  
Reinforced Concrete ◽  
Protective Layer ◽  
Polymer Coatings ◽  
Nonlinear Finite Element ◽  
Blast Load ◽  
Structural Elements ◽  
Displacement Control ◽  
Positive Effects ◽  
Dynamic Loadings ◽  
Very High

The main distinction of blast load from other types of dynamic loadings is its impulsive nature, where the loads usually act for a very short duration but transmit very high impulsive pressures. This paper presents an overview of the present retrofitting techniques in use to enhance the capacity of structural elements to withstand the effects of blast loads, and introduces an alternative retrofitting approach by utilizing polymer coatings. The authors have demonstrated the positive effects of this approach by conducting a numerical investigation on the behavior of an unretrofitted reinforced concrete panel subjected to the blast load from a 2 kg charge at 1.6 m stand-off distance, and subsequently comparing its performance with several polymer coated panels. The analysis was performed by using an explicit nonlinear finite element (FE) code. The results demonstrate the contributions of this technique in terms of panel displacement control and energy dissipation. Considering that the polymer coating can also act as a protective layer in improving the durability of structural materials, this technique can also be optimized favorably to enhance the overall sustainability of structures.

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 STRUCTURAL DESIGN OF POLYMER PROTECTIVE COATINGS FOR REINFORCED CONCRETE STRUCTURES. PART I: THEORETICAL CONSIDERATIONS

2007 ◽  
Vol 13 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Zenonas Kamaitis
Keyword(s):  
Reinforced Concrete ◽  
Protective Coatings ◽  
Concrete Structures ◽  
Concrete Surface ◽  
Polymer Coatings ◽  
Concrete Cover ◽  
Reinforced Concrete Structures ◽  
Coating Materials ◽  
Barrier Materials ◽  
Mechanism Of Degradation

In a number of situations reinforced concrete structures must be protected by barrier materials to prevent contact with aggressive agents. One of the ways to protect concrete structures from corrosion is to use protective polymer coatings. Polymers as coating materials are not totally resistant and impermeable to all aggressive agents. Gases, vapors and liquids penetrate into a polymer so that the polymer mass swells and eventually disintegrates. However, the penetration/disintegration progresses at a much lower rate than that in the concrete. Surface coatings are able to reduce considerably the penetration, to slow down the rate of deterioration of concrete cover and to overcome most durability problems associated with external attack. In this article the mechanism of degradation of polymer coatings are analyzed. Methodology and predictive models for the degradation over time caused by aggressive actions of polymer coatings are presented. Proposed models can be applied to design of polymer coatings. Such a design of coatings is presented in a simple form for engineering design purposes.

scholarly journals SHRINKAGE INFLUENCE ON STRESS-STRAIN STATE OF COMPOSITE MASONRY MEMBERS/SUSITRAUKIMO DEFORMACIJŲ ĮTAKA KOMPLEKSINIŲ MŪRO ELEMENTŲ ĮTEMPIŲ IR DEFORMACIJŲ BŪVIUI

2001 ◽  
Vol 7 (3) ◽  
pp. 177-183 ◽  
Author(s):  
Gediminas Marčiukaitis
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Modulus Of Elasticity ◽  
Masonry Structures ◽  
Cross Section Area ◽  
Section Area ◽  
Deformation Properties ◽  
Different Types ◽  
Tension And Compression

Composite masonry structures consists of various units (bricks or ceramic, concrete and other blocks) masonry and concrete or reinforced concrete layers. Analysis has shown that in most cases deformation properties of masonry, concrete and reinforced concrete are different. There is a big difference in modulus of elasticity and shrinkage deformations. Methods for determination of shrinkage and modulus of elasticity for different types of masonry and reinforced concrete have been presented. Analysis of distribution of stresses and deformations in layers has shown that for a given difference of shrinkage in layers the stresses of tension and compression in the layers depend on the cross-section area of these layers and the ratio of the modulus of elasticity. Formulas are given for calculation of these stresses.

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