scholarly journals Energy and seismic drawbacks of masonry: a unified retrofitting solution

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
F. Longo ◽  
A. Cascardi ◽  
P. Lassandro ◽  
M. A. Aiello
Keyword(s):  
Thermal Resistance ◽  
Mechanical Performance ◽  
Point Of View ◽  
Experimental Program ◽  
Masonry Walls ◽  
Shear Tests ◽  
Plane Shear ◽  
Innovative Solutions ◽  
Inorganic Matrix ◽  
Comfort Criteria

AbstractAll over the world, a large part of existing buildings is not adequate to satisfy the safety requirement and the thermal comfort criteria. For this reason, the interest in structural and energy retrofitting systems has steadily grown in the last decades. In this scenario, an innovative thermal resistant geopolymer mortar has been developed and used for Inorganic Matrix Composite (IMC) systems aimed to a combined seismic and energy new retrofitting technique. The geopolymer-based IMC is able to ensure competitive mechanical properties with respect to the traditional lime-based IMCs and, at the same time, a significant reduction in thermal conductivity. In this paper, an experimental program is reported considering small-scaled masonry panels with double-side IMC-retrofitting and determining both the in-plane shear strength and the thermal resistance. The experimental shear tests are aimed to compare the mechanical performance of the geopolymer innovative systems with those of the traditional lime-based ones. Moreover, the thermal resistance gain of the innovative solutions was measured and compared with traditional systems. The results evidenced the effectiveness of the proposed technique that significantly improved the performances of masonry walls from both the thermal and the mechanical point of view.

Half-Scale Tests on Masonry Panels Strengthened with Pultruded FRP Frames

2019 ◽  
Vol 817 ◽  
pp. 95-102
Author(s):  
Francesca Sciarretta ◽  
Salvatore Russo
Keyword(s):  
Shear Strength ◽  
Epoxy Adhesive ◽  
Analytical Models ◽  
Masonry Walls ◽  
Bolted Joint ◽  
Shear Tests ◽  
Plane Shear ◽  
Lime Mortar ◽  
Clay Bricks ◽  
Connection System

The research explores the capabilities of frames of pultruded FRP profiles as seismic strengthening for masonry walls. A programme is currently in progress at the IUAV University of Venice, consisting of in-plane shear tests on half-scale panels. The selected masonry type is traditional, i.e. clay bricks and lime mortar joints. The goal is to assess the effectiveness of the strengthening system with respect to the undamaged condition of masonry. A particular focus is on the connection system between the panel and the frame, i.e. epoxy adhesive connection and bolted joint. The results will be implemented in FEM analyses and analytical models to predict the system's and the joints' shear strength.

Fabric-Reinforced Cementitious Matrix (FRCM): A New Italian Guideline under Development

2014 ◽  
Vol 624 ◽  
pp. 3-10 ◽  
Author(s):  
Luigi Ascione ◽  
Geminiano Mancusi ◽  
Anna D'Aponte
Keyword(s):  
Failure Mechanisms ◽  
Point Of View ◽  
Constitutive Behavior ◽  
Experimental Program ◽  
Uniaxial Tensile ◽  
Aramid Fibers ◽  
Cementitious Matrix ◽  
Glass Carbon ◽  
Fabric Reinforced Cementitious Matrix ◽  
Inorganic Matrix

In addition toFibre-Reinfocedcomposite materials, which are made of long glass/carbon/aramid fibers embedded in a polymer matrix (FRP), the use ofFRCMcomposites (Fabric-Reinforced Cementitious Matrix) is becoming more and more widespread. As far as this specific case, the inorganic matrix guarantees many advantages, especially when dealing with masonry substrates, including a good compatibility from both a physical and a chemical point of view and the possibility of wet lay-up application. Despite their wide use in technical applications, the constitutive behavior and the failure mechanisms of FRCMs have not been adequately studied. As a consequence, a final assessment upon which criteria have to be used for verification and qualification ofFRCMsis still missing. In the context of a recent experimental program-still under development-cooperated by many Italian academic laboratories, that is aimed at detecting the main features of the constitutive behavior of these materials, a discussion seems to be appropriate on the initial experimental results obtained at Salerno University on manyFRCMspecimens tested under uniaxial tensile loads.

scholarly journals In-plane shear strength and damage fragility functions for partially-grouted reinforced masonry walls with bond-beam reinforcement

2021 ◽  
Vol 242 ◽  
pp. 112569
Author(s):  
Zhiming Zhang ◽  
Juan Murcia-Delso ◽  
Cristián Sandoval ◽  
Gerardo Araya-Letelier ◽  
Fenglai Wang
Keyword(s):  
Shear Strength ◽  
Masonry Walls ◽  
Fragility Functions ◽  
Plane Shear ◽  
Reinforced Masonry

scholarly journals Experimental and Numerical Investigation on the Steel Reinforced Grout (SRG) Composite-to-Concrete Bond

2020 ◽  
Vol 4 (4) ◽  
pp. 182
Author(s):  
Luciano Ombres ◽  
Salvatore Verre
Keyword(s):  
Bond Length ◽  
Failure Modes ◽  
Peak Load ◽  
Element Model ◽  
Test Results ◽  
Shear Tests ◽  
Bond Slip ◽  
Bond Behavior ◽  
Direct Shear Tests ◽  
Inorganic Matrix

In the paper, the bond between a composite strengthening system consisting of steel textiles embedded into an inorganic matrix (steel reinforced grout, SRG) and the concrete substrate, is investigated. An experimental investigation was carried out on medium density SRG specimens; direct shear tests were conducted on 20 specimens to analyze the effect of the bond length, and the age of the composite strip on the SRG-to-concrete bond behavior. In particular, the tests were conducted considering five bond length (100, 200, 250, 330, and 450 mm), and the composite strip’s age 14th, 21st, and 28th day after the bonding. Test results in the form of peak load, failure modes and, bond-slip diagrams were presented and discussed. A finite element model developed through commercial software to replicate the behavior of SRG strips, is also proposed. The effectiveness of the proposed numerical model was validated by the comparison between its predictions and experimental results.

Determination of In-plane Shear Strength of Unidirectional Composite Materials Using the Off-axis Three-point Flexure and Off-axis Tensile Tests

2010 ◽  
Vol 44 (21) ◽  
pp. 2487-2507 ◽  
Author(s):  
G. Vargas ◽  
F. Mujika
Keyword(s):  
Shear Strength ◽  
Composite Materials ◽  
Tensile Tests ◽  
Unidirectional Composite ◽  
Point Of View ◽  
Experimental Point ◽  
Plane Shear ◽  
Lift Off ◽  
Flexure Test

The aim of this work is to compare from an experimental point of view the determination of in-plane shear strength of unidirectional composite materials by means of two off-axis tests: three-point flexure and tensile. In the case of the off-axis three-point flexure test, the condition of small displacements and the condition of lift-off between the specimen and the fixture supports have been taken into account. Some considerations regarding stress and displacement fields are presented. The in-plane shear characterization has been performed on a carbon fiber reinforced unidirectional laminate with several fiber orientation angles: 10°, 20°, 30°, and 45°. Test conditions for both off-axis experimental methods, in order to ensure their applicability, are presented. Off-axis flexure test is considered more suitable than off-axis tensile test for the determination of in-plane shear strength.

Lateral Load Performance of Panelized Wood I-Joist Floor Systems

2020 ◽  
Vol 70 (4) ◽  
pp. 428-438
Author(s):  
Sigong Zhang ◽  
Ying Hei Chui ◽  
David Joo
Keyword(s):  
Load Transfer ◽  
Mechanical Performance ◽  
Small Scale ◽  
Construction Time ◽  
Plane Shear ◽  
Floor Systems ◽  
Diaphragm Action ◽  
Wood Frame ◽  
Strength And Stiffness ◽  
Frame Construction

Abstract Panelized light wood frame construction is becoming more popular due to the faster construction time and shortage of onsite skilled labor. To use light wood frame panels effectively in panelized floor systems, panel-to-panel joints must be fastened adequately to allow load transfer between panels. They must also possess in-plane shear strength and stiffness comparable to stick-built, staggered-sheathed assemblies. This study was designed to develop efficient and effective panel-to-panel joints for connecting adjacent floor panels built with wood I-joists and evaluate the efficiency of the joints in achieving diaphragm action. At first, a number of these panel-to-panel joints were tested in the laboratory using a small-scale diaphragm test setup to determine their efficiency in transferring in-plane forces between panels. Test results showed that a small decrease in in-plane stiffness was expected for the most effective joints, but their strengths were significantly higher than at the same location in a conventional site-built floor diaphragm. The presence of blockings and use of two-row nailing were found to considerably improve stiffness and strength. These features can be used to mitigate the potential reduction in mechanical performance of panelized floor construction, in comparison with the site-built wood I-joist floor.

Mechanical Properties of Various Models of Interlocking Concrete Blocks under In-Plane and Out-of-Plane Loads

2021 ◽  
Vol 881 ◽  
pp. 149-156
Author(s):  
Mochamad Teguh ◽  
Novi Rahmayanti ◽  
Zakki Rizal
Keyword(s):  
Mechanical Properties ◽  
Building Material ◽  
Experimental Tests ◽  
Concrete Block ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Plane Shear ◽  
Out Of Plane ◽  
Concrete Blocks ◽  
Local Materials

Building material innovations in various interlocking concrete block masonry from local materials to withstand lateral earthquake forces is an exciting issue in masonry wall research. The block hook has an advantage in the interlocking system's invention to withstand loads in the in-plane and out-of-plane orientations commonly required by the masonry walls against earthquake forces. Reviews of the investigation of in-plane and out-of-plane masonry walls have rarely been found in previous studies. In this paper, the results of a series of experimental tests with different interlocking models in resisting the simultaneous in-plane shear and out-of-plane bending actions on concrete blocks are presented. This paper presents a research investigation of various interlocking concrete blocks' mechanical properties with different hook thicknesses. Discussion of the trends mentioned above and their implications towards interlocking concrete block mechanical properties is provided.

Shear tests on thermal insulating clay unit masonry walls with thin layer mortar

Mauerwerk ◽  
2018 ◽  
Vol 22 (6) ◽  
pp. 385-398 ◽  
Author(s):  
Detleff Schermer ◽  
Jonathan Schmalz ◽  
Udo Joachim Meyer ◽  
Matija Gams ◽  
Marjana Lutman ◽  
...  
Keyword(s):  
Thin Layer ◽  
Masonry Walls ◽  
Shear Tests ◽  
Thermal Insulating

Performance of Plain Journal Bearings Operating Under Vortex Flow Conditions

1974 ◽  
Vol 96 (1) ◽  
pp. 145-149 ◽  
Author(s):  
J. Freˆne ◽  
M. Godet
Keyword(s):  
Reynolds Number ◽  
Friction Torque ◽  
Point Of View ◽  
Taylor Vortex ◽  
Experimental Program ◽  
Frictional Torque ◽  
Taylor Vortices ◽  
Attitude Angle ◽  
Relative Eccentricity ◽  
High Reynolds

An experimental program conducted on an original device was undertaken to study the performance of plain bearings operating at sufficiently high Reynolds number to introduce Taylor vortices. Curves of relative eccentricity, attitude angle, and friction torque were obtained versus speed and load. Experimental results conducted for Reynolds number smaller than 1100 indicate that both laminar and Taylor vortex regimes are encountered. The occurrence of the vortices is identified by a break in the slope of the friction torque versus speed curves. The position of the break is in good agreement with the theoretical predictions of Di Prima and Ritchie. From the practical point of view, the data show that for constant viscosity the occurence of Taylor vortices does not alter the curves of eccentricity versus either speed or load but modifies the attitude angle and frictional torque. In turn, the increase in frictional torque, and subsequently of temperature may cause a decrease in viscosity and thus a drop in load carrying capacity for fluids such as oils whose variations of viscosity with temperature is large.

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