Discussion on mechanical behavior of joints using post-installed anchors and concrete surface roughening for seismic retrofitting

2014 ◽  
pp. 837-846
Author(s):  
Yuya Takase ◽  
Takahide Abe ◽  
Takaaki Ikeda ◽  
Toshinaga Wada ◽  
Keiichi Katori ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Concrete Surface ◽  
Seismic Retrofitting ◽  
Surface Roughening

scholarly journals Characterization of Shear Strength of FRP Anchors

2018 ◽  
Vol 199 ◽  
pp. 09008
Author(s):  
Philipp Mahrenholtz ◽  
Jae-Yeol Cho ◽  
Ja-Min Park ◽  
Rolf Eligehausen
Keyword(s):  
Load Capacity ◽  
Concrete Surface ◽  
Shear Loading ◽  
Seismic Retrofitting ◽  
Static Tests ◽  
Cyclic Shear ◽  
Concrete Body ◽  
Seismic Tests ◽  
Frp Sheet

A critical performance aspect of FRP retrofitted concrete elements is the bonding of the FRP sheet to the concrete surface. In general, the performance is limited by the debonding of the loaded FRP sheets from the concrete surface. One method to delay debonding and enhance the capacity is the use of FRP anchors which interlock the FRP sheet to the concrete body. FRP anchors are made of rolled FRP fibres epoxied into in predrilled boreholes. There are a considerable number of studies on FRP strengthening methods available, and also FRP anchors attract more attention of the research community recently. However, to date FRP anchors were tested in a system together with the FRP sheet attached to the concrete, inhibiting the development of general design models. Moreover, the anchor behaviour was never tested for cyclic loads, though most applications are for seismic retrofitting schemes and cyclic shear loading generally results in reduced load capacity due to fatigue failure. To overcome the deficit in knowledge, shear tests on various FRP anchors were carried out. For these tests, FRP anchors were installed in concrete specimens on a separating steel section. The FRP anchor was then directly loaded to determine the capacity of the isolated component. This paper describes the testing approach and procedure. Details on the experimental results for static tests are presented and an outlook on seismic tests is given.

EFFECT OF SURFACE ROUGHENING ON CONCRETE/TRM BOND

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Kshitij C. Shrestha ◽  
Usama Ebead ◽  
Adel Younis
Keyword(s):  
Concrete Slab ◽  
Surface Preparation ◽  
Concrete Surface ◽  
Concrete Slabs ◽  
Surface Roughening ◽  
Textile Materials ◽  
Bond Performance ◽  
Textile Reinforced Mortar ◽  
Different Levels ◽  
Effect Of Surface

Textile reinforced mortar (TRM) is applied on the concrete surface with the aim of strengthening reinforced concrete structures. The performance of the strengthened structural system is directly related to the bond between the existing concrete substrate and the freshly applied TRM layer. This paper presents the results of an experimental study carried out to investigate the significance of concrete surface preparation, performed prior to strengthening, on the bonding behavior of the TRM system. For this purpose, concrete slabs of size (500 mm × 500 mm × 100 mm) were prepared and strengthened using a 10-mm thick TRM layer. After that, the bond performance of the strengthening layer with the concrete slab was assessed using the pull-off test. Three different levels of surface roughening were considered before strengthening: (i) no roughening (regarded as the reference), (ii) low roughening level, and (iii) high roughening level. Two types of textile materials are used in strengthening systems: carbon and polyparaphenylene benzobisoxazole (PBO). A total number of 72 pull-off tests were performed, of which the results were analyzed to examine the significance of the test variables. Results revealed that as the concrete surface is more roughened before strengthening, the bond between concrete substrate and TRM layer becomes stronger. Moreover, the PBO-TRM systems exhibit more desirable bonding behavior compared to the carbon-TRM counterpart.

Application of TEM to Deformation, Wear, and Fracture of Ceramics

1974 ◽  
Vol 32 ◽  
pp. 472-473
Author(s):  
B. J. Hockey
Keyword(s):  
Wear Resistance ◽  
High Temperature ◽  
Mechanical Behavior ◽  
Brittle Materials ◽  
High Temperature Strength ◽  
Wide Range ◽  
Corrosive Environments ◽  
Further Development

Ceramics, such as Al2O3 and SiC have numerous current and potential uses in applications where high temperature strength, hardness, and wear resistance are required often in corrosive environments. These materials are, however, highly anisotropic and brittle, so that their mechanical behavior is often unpredictable. The further development of these materials will require a better understanding of the basic mechanisms controlling deformation, wear, and fracture.The purpose of this talk is to describe applications of TEM to the study of the deformation, wear, and fracture of Al2O3. Similar studies are currently being conducted on SiC and the techniques involved should be applicable to a wide range of hard, brittle materials.

Observation of surface roughening on Cu(1, 1, 5)

1987 ◽  
Vol 48 (6) ◽  
pp. 1017-1028 ◽  
Author(s):  
F. Fabre ◽  
D. Gorse ◽  
B. Salanon ◽  
J. Lapujoulade
Keyword(s):  
Surface Roughening

The influence of the addition of ground olive stone on the thermo-mechanical behavior of compressed earth blocks

2020 ◽  
Vol 108 (2) ◽  
pp. 203
Author(s):  
Samia Djadouf ◽  
Nasser Chelouah ◽  
Abdelkader Tahakourt
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Mechanical Behavior ◽  
Agricultural Waste ◽  
Hydraulic Press ◽  
Dry Density ◽  
Olive Stone ◽  
Compressed Earth Blocks ◽  
Clay Matrix ◽  
Earth Blocks

Sustainable development and environmental challenges incite to valorize local materials such as agricultural waste. In this context, a new ecological compressed earth blocks (CEBS) with addition of ground olive stone (GOS) was proposed. The GOS is added as partial clay replacement in different proportions. The main objective of this paper is to study the effect of GOS levels on the thermal properties and mechanical behavior of CEB. We proceeded to determining the optimal water content and equivalent wet density by compaction using a hydraulic press, at a pressure of 10 MPa. The maximum compressive strength is reached at 15% of the GOS. This percentage increases the mechanical properties by 19.66%, and decreases the thermal conductivity by 37.63%. These results are due to the optimal water responsible for the consolidation and compactness of the clay matrix. The substitution up to 30% of GOS shows a decrease of compressive strength and thermal conductivity by about 38.38% and 50.64% respectively. The decrease in dry density and thermal conductivity is related to the content of GOS, which is composed of organic and porous fibers. The GOS seems promising for improving the thermo-mechanical characteristics of CEB and which can also be used as reinforcement in CEBS.

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