Earthquake Disaster Mitigation through Retrofitting of Unreinforced Concrete Block Masonry Buildings

2011 ◽  
Vol 255-260 ◽  
pp. 2627-2631
Author(s):  
Muhammad Shoaib ◽  
Amjad Naseer ◽  
Khan Shahzada ◽  
Akhtar Naeem Khan ◽  
M. Ashraf
Keyword(s):  
Experimental Study ◽  
Concrete Block ◽  
Unreinforced Masonry ◽  
Experimental Results ◽  
Disaster Mitigation ◽  
Masonry Buildings ◽  
Future Scenario ◽  
Scenario Earthquakes ◽  
Before And After ◽  
Lateral Strength

This paper presents an experimental study on the improvement of unreinforced block masonry buildings against earthquake disasters. Unreinforced concrete block masonry piers have been tested for lateral strength before and after retrofitting. Welded mesh and injection of cement grout techniques have been used for piers retrofitting. The analysis of experimental results demonstrates that proper retrofitting can decrease the risk to concrete block masonry buildings in future scenario earthquakes. Retrofitting increases not only the overall strength of unreinforced masonry piers but also the ductility.

Seismic Resistance of Unreinforced Brick Masonry Buildings: An Experimental Study

2011 ◽  
Vol 255-260 ◽  
pp. 2622-2626 ◽  
Author(s):  
Azmat Ullah ◽  
Khan Shahzada ◽  
Akhtar Naeem Khan ◽  
Amjad Naseer ◽  
Mohammad Ashraf ◽  
...  
Keyword(s):  
Experimental Study ◽  
Axial Compression ◽  
Rice Husk ◽  
Brick Masonry ◽  
Experimental Results ◽  
Wire Mesh ◽  
Seismic Resistance ◽  
Masonry Buildings ◽  
Wall Surface ◽  
Diagonal Compression

This paper presents a study on seismic resistance of typical single and double storey masonry buildings constructed in the southern districts of Pakhthunkhwa, Pakistan. Two types of bricks; wooden and rice husk burnt bricks, have been investigated in combination with mud and cement-sand mortar. Plane and reinforced specimens have been tested in axial compression and diagonal compression. Analysis of the experimental results show that both single and double storey buildings constructed in the study area with mud mortar and mud plaster are seismically vulnerable. However application of the wire mesh on wall surface subsequently plastered increases the strength significantly and make the structure resistant to the earthquake forces.

scholarly journals Effect of laser deweighting on properties of ZL205A aluminum alloy

2021 ◽  
Vol 2137 (1) ◽  
pp. 012033
Author(s):  
Guang Li ◽  
Zhipeng Wei ◽  
Junlong Wang ◽  
Yangyang Zhang ◽  
Chen Wang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Aluminum Alloy ◽  
Surface Morphology ◽  
Pulse Laser ◽  
Process Parameters ◽  
Experimental Results ◽  
Matrix Properties ◽  
Before And After ◽  
The Matrix

Abstract In this paper, a nanosecond fiber pulse laser is used to carry out the experimental study on laser weight removal of ZL205A aluminum alloy gyro rotor. By optimizing the process parameters of laser weight removal, better surface morphology was obtained. The effects of surface roughness, metallographic structure and hardness of samples before and after laser deweighting were analyzed. The experimental results show that the laser weight removal does not affect the matrix properties of ZL205A aluminum alloy. The laser de-weight technology is suitable for the balance of ZL205A aluminum alloy gyro rotor.

Experimental Study on Lateral Strength Evaluation of Unreinforced Masonry-Infilled RC Frame

2016 ◽  
Vol 32 (3) ◽  
pp. 1725-1747 ◽  
Author(s):  
Kiwoong Jin ◽  
Ho Choi ◽  
Yoshiaki Nakano
Keyword(s):  
Compressive Strain ◽  
Concrete Block ◽  
Unreinforced Masonry ◽  
School Buildings ◽  
Rc Frame ◽  
Rc Frames ◽  
Equivalent Strut ◽  
Lateral Strength ◽  
Curvature Distribution ◽  
Typical School

In this study, RC frames with unreinforced masonry (URM) infill for typical school buildings in Korea are experimentally investigated to evaluate their seismic performance. For this purpose, one-bay, one-fourth scale specimens, with unreinforced concrete block (CB) infill having different boundary conditions due to beam rigidity, are tested under in-plane cyclic loading, using a distinctive measurement scheme consisting of three-axis strain gauges attached to all CB units. In this paper, the diagonal strut mechanism of CB infill including its main strut angle, average compressive strain, and equivalent strut width is discussed using principal compressive strains on CB units. The lateral strength carried by CB infill and RC frame from the overall response of the specimens is also explained, based on the compressive stress acting on the infill and the curvature distribution along RC members during the test.

scholarly journals Strengthening of Unreinforced Masonry with Fibre Reinforced Concrete

2018 ◽  
Vol 7 (3.12) ◽  
pp. 550
Author(s):  
S Gayathri ◽  
S Kanchidurai ◽  
P A. Krishanan ◽  
K Baskar
Keyword(s):  
Experimental Study ◽  
Bond Strength ◽  
Steel Fibre ◽  
Unreinforced Masonry ◽  
Strength Test ◽  
Geometrical Parameters ◽  
Masonry Buildings ◽  
Fibre Reinforced Concrete ◽  
Flexural Bond Strength ◽  
Masonry Prism

Unreinforced Masonry buildings are vulnerable because the walls and parapets aren’t securely tried to the floors and roof. In an earthquake, parapets can break away, walls pull apart and the floors collapse. This paper presents the experimental study performed on the flexural bond strength of unreinforced brick masonry prism. Different percentage (1%, 2%, and 3%) of Hooked Steel Fibre was used. One of the most geometrical parameters of fibres is their length, diameter and aspect ratio. Masonry prism will be cast and tested as per the guidelines are given in ASTM E518/E518-15. The results of the flexural bond strength test of prisms with and without fibre discussed.

Seismic Capacity Assessment of Unreinforced Concrete Block Masonry Buildings in Pakistan Before and After Retrofitting

2014 ◽  
Vol 19 (3) ◽  
pp. 357-382 ◽  
Author(s):  
Zeeshan Ahmad ◽  
Khan Shahzada ◽  
Bora Gencturk ◽  
Akhtar Naeem Khan ◽  
Rashid Rehan ◽  
...  
Keyword(s):  
Concrete Block ◽  
Capacity Assessment ◽  
Masonry Buildings ◽  
Seismic Capacity ◽  
Before And After

scholarly journals Experimental Study on Rockfall Mechanism of Platy Rock on a Complex Slope

2020 ◽  
Vol 10 (8) ◽  
pp. 2849
Author(s):  
Xiaohui Liao ◽  
Qi Ouyang ◽  
Haiyang Liu ◽  
Juanjuan Sun ◽  
Xueliang Wang ◽  
...  
Keyword(s):  
Experimental Study ◽  
High Speed ◽  
Slope Angle ◽  
Coefficient Of Restitution ◽  
Experimental Results ◽  
Rock Fall ◽  
Restitution Coefficient ◽  
Hazard Control ◽  
Before And After ◽  
Control Work

The rock fall trajectory and its mechanisms are the most difficult to predict, owing to the complexity of the slope and the Irregular shape of falling rocks. To acquire a better knowledge of the rock fall mechanism of platy rock and to investigate the influence of various impact parameters, a comprehensive physical model experimental study was undertaken based on 3D printing technology using a high-speed camera and specially developed block release system. Based on the experimental results, the effects of the slope angle on the stopping position, the instantaneous kinetic energy and collision position of platy rock block were analyzed. Meanwhile, the effects of movement forms of platy rock before and after collision on the normal coefficient of restitution and the tangent coefficient of restitution were discussed. It is observed that rock fall trajectory depends not only on slope material characteristics, slope angle but also on factors related to the platy block (weight, size and shape). The experimental results showed the value of restitution coefficient exceeding 1 has an important relation with the combination of various movement forms (including the flip motion) and the change of movement forms of platy rock before and after the collision. A new feasible experimental method for research and prevention of rock fall disaster was put forward. It would be important and helpful to the geo-hazard control work.

Experimental Study on the Effectiveness of Masonry-Basalt TRM Reinforced Systems Characterized by Different Fiber Grid Densities

2017 ◽  
Vol 747 ◽  
pp. 266-273 ◽  
Author(s):  
Carmelo Caggegi ◽  
Giuseppe Ferrara ◽  
Emma Lanoye ◽  
Đức Bình Nguyễn ◽  
Aron Gabor ◽  
...  
Keyword(s):  
Experimental Study ◽  
Experimental Results ◽  
Masonry Buildings ◽  
Suitable Solution ◽  
Historical Masonry ◽  
Promising Solution ◽  
Textile Reinforced Mortar ◽  
Single Shear ◽  
Mortar Matrix

The use of Textile Reinforced Mortar (TRM) systems is emerging as a suitable solution for strengthening historical masonry buildings, as they are made of compatible materials often resulting in limited and reversible interventions. Moreover, TRM systems reinforced by basalt textile are a very promising solution. This study presents the results of single shear-lap tests intended at defining and comparing the effectiveness of three reinforced basalt TRM-masonry systems characterized by different strengthening ratios. These systems have been obtained by inserting one, two or three basalt grids in the TRM composite. The experimental results show that a slippage of the fiber roving within the mortar matrix frequently occurs in the reinforced system characterized by a low strengthening ratio; the increase in fiber grid density often results in a brittle debonding between the lower and the upper layer of mortar matrix. The results show that a high strengthening ratio may result in decreasing the strengthening performances.

scholarly journals In-plane retrofitting of masonry structures by using GFRP strips in the Bedjoints

2021 ◽  
Author(s):  
Fathollah Osmanzadeh ◽  
Elshan Ahani ◽  
Behzad Rafezy ◽  
Mir Naghi Mousavi
Keyword(s):  
Ductile Failure ◽  
Unreinforced Masonry ◽  
Masonry Wall ◽  
Masonry Structures ◽  
Clay Bricks ◽  
Historical Structures ◽  
Before And After ◽  
Lateral Strength ◽  
Historical Masonry ◽  
Strength And Stiffness

Abstract Many unreinforced masonry structures were vulnerable in the past earthquakes and required retrofitting. However, the vulnerability of masonry structures could solve by providing numerous retrofitting approaches, scarcity of appropriate methods that may provide a solution for the historical masonry structures with lesser effects on their façade is vehemently sensible. In this study, two one-third scale masonry wall specimens made by clay bricks were tested under constant vertical and cyclic lateral loading. The specimens consist of an unreinforced wall and a wall retrofitted by GFRP strips. This study investigates the seismic behavior of unreinforced masonry walls before and after using GFRP strips on their bedjoints. To this purpose, various patterns of using GFRP strips have been studied by simplified micro-modeling. The consequence indicates that the proposed retrofitting technique could improve the lateral strength and stiffness of the unreinforced masonry wall along with a considerable increase in the energy dissipation and ductility content, which leads to making a change in the behavior of the wall from brittle to ductile failure. The proposed method could apply to the modern historical structures in which cement mortar has been used as an adhesive between the masonry layers.

scholarly journals Experimental study of the $ \gamma p \rightarrow K^{0}\Sigma^{+}$, $ \gamma n \rightarrow K^{0} \Lambda$, and $ \gamma n \rightarrow K^{0} \Sigma^{0}$ reactions at the Mainz Microtron

2019 ◽  
Vol 55 (11) ◽  
Author(s):  
C. S. Akondi ◽  
K. Bantawa ◽  
D. M. Manley ◽  
S. Abt ◽  
P. Achenbach ◽  
...  
Keyword(s):  
Experimental Study ◽  
Cross Sections ◽  
Differential Cross ◽  
Legendre Polynomials ◽  
Neutral Kaon ◽  
Experimental Results ◽  
Differential Cross Sections ◽  
Theoretical Predictions ◽  
Photoproduction Reactions ◽  
Insight Into

Abstract.This work measured $ \mathrm{d}\sigma/\mathrm{d}\Omega$dσ/dΩ for neutral kaon photoproduction reactions from threshold up to a c.m. energy of 1855MeV, focussing specifically on the $ \gamma p\rightarrow K^0\Sigma^+$γp→K0Σ+, $ \gamma n\rightarrow K^0\Lambda$γn→K0Λ, and $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 reactions. Our results for $ \gamma n\rightarrow K^0 \Sigma^0$γn→K0Σ0 are the first-ever measurements for that reaction. These data will provide insight into the properties of $ N^{\ast}$N* resonances and, in particular, will lead to an improved knowledge about those states that couple only weakly to the $ \pi N$πN channel. Integrated cross sections were extracted by fitting the differential cross sections for each reaction as a series of Legendre polynomials and our results are compared with prior experimental results and theoretical predictions.

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