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Experimental study on retrofitting earth block masonry
Published in Koen Van Balen, Els Verstrynge, Structural Analysis of Historical Constructions: Anamnesis, Diagnosis, Therapy, Controls, 2016
Ioanna Papayianni, Myronas Drygiannakis, Georgios-Marios Zarmpoutis, Georgios Mitolidis, Konstantinos Katakalos
Three different types of mesh were used for the masonry reinforcement. Some triplets were reinforced with unidirectional SRP mesh, while the wall specimens were reinforced with a unidirectional SRP and a bidirectional GFRP mesh. The main mechanical characteristics of the meshes measured via tensile tests, are shown in Table 5. A general classification of the specimens based on the type of materials and type of loading is indicated in Table 6. Testing adhesion of mortar coating by using Pull-off Test The test was carried out according toASTM D454109e1, with an adhesion tester with load capacity of 16 kN. The Pull-off test is performed to determine the adhesion between the different materials by tensile strength. The test aims at checking the adhesion between the finishing layer of coating mortar-mesh and the masonry. The test principle consisted in the application of an increasing load on a certain and isolated surface until the breakage of the element: in this
A repair quality control with elastic waves based methods vs. concrete substrate quality
Published in F. Dehn, H.-D. Beushausen, M.G. Alexander, P. Moyo, Concrete Repair, Rehabilitation and Retrofitting IV, 2015
A. Garbacz, T. Piotrowski, L. Courard, B. Bissonnette
An adhesion in repair systems is one of the most important factors that affect the durability of repair. The adhesion depends on many phenomena taking place at interface zone. According to the standards and guidelines, e.g. European Standard EN 1504-10 and ACI Concrete Repair Manual, both bond strength and bond quality should be evaluated. The pull-off test is recommended for assessment of a bond strength. The use of pull-off test, due to its semi-destructive character, is restricted by owners and managers. Therefore, the elaboration of reliable nondestructive method for an adhesion mapping is one of the most important tasks. A majority of NDT methods mentioned in EN 1504-10 and ACI Concrete Repair Manual for assessment of concrete structures are based on propagation of stress waves. Particularly ultrasonic methods (UPV), Impact Echo (IE) and Impulse-Response (IR) methods are recommended for evaluation of repair quality.
Simultaneous Incorporation of Magnesium and Fluorine Ions in Hydroxyapatite Coatings on Metallic Implant for Osseointegration and Stability
Published in Sam Zhang, Hydroxyapatite Coatings for Biomedical Applications, 2013
Yanli Cai, Sam Zhang, Soon-Eng Ong, Xianting Zeng, Wilson Wang
The pull-off test is useful in providing information on the adhesion properties at the interface of the coating and the substrate and is a relatively quantitative method for adhesion strength assessment. The adhesion strength is determined by applying a uniaxial tensile load to a cylindrical test assembly composed of one coated specimen bonded to an uncoated component. The coated and uncoated components are bonded together by the adhesive. The materials and dimensions of the uncoated component shall be the same as those of the coated specimen. After the preparation, the test assembly is placed in the grips of the tensile testing machine, and the tensile load is applied at a constant velocity until complete separation of the components is achieved [56]. Together with other testing methods of adhesion strength, the detailed bonding characteristics of the coating and the substrate can be obtained.
Evaluation of pull-off strength for steel fibre reinforced self-compacting concrete repair overlays
Published in European Journal of Environmental and Civil Engineering, 2023
Omolbanin Arasteh Khoshbin, Rahmat Madandoust, Malek Mohammad Ranjbar
The pull-off test is used to check the bonding quality of concrete layers. This test determines the maximum vertical force required to ensure the failure in the concrete specimen’s surface or depth (depending on the method conditions). The failure position indicates the weakest zone from the adhered area between the disc and concrete to the lowest position of the borehole (if there is any). In this test, which is performed according to ASTM C1583 (ASTM C1583-04, 2004) standard, tensile strength is a prominent factor extracted based on the pull-off results. The pull-off test device is connected in such a way that an actuator attaches to the steel disc and uses it to apply a tensile load on the concrete surface. In addition, a data logger is used to store the maximum amount of force applied. The adhesive used for this experiment was selected from a two-component epoxy family.
Performance characteristics of epoxy asphalt paving material for thin orthotropic steel plate decks
Published in International Journal of Pavement Engineering, 2020
Can Chen, Wolfgang O. Eisenhut, Kreisler Lau, Ashley Buss, John Bors
To the bridge pavement technologist, orthotropic steel decks with their inherent flexibility present a particular challenge. The design of the wearing course must take into account the flexibility of the deck, pavement mixture stability, density and weight, fatigue under heavy traffic load, as well as skid characteristics. The following laboratory test methods were used to evaluate the epoxy asphalt and mixture properties: Binder direct tensile test, which gives the mechanical characterisation of binder tensile properties. ASTM D 412 – Standard Tension Test for Vulcanised Rubber and Thermoplastic Elastomers.Marshall stability test, which can assess the stability of the pavement immediately after placement and upon full cure. ASTM D 6927 – Standard Test for Marshall Stability and Flow of Asphalt Mixtures.Flexural beam fatigue test, which measures the effects of repetitive loading on the steel plate and the epoxy asphalt mix. Modified ASTM C 293 – Standard Test for Flexural Strength of Concrete (Using Simple Beam With Centre-Point Loading).Pull-off test, which measures the binder adhesive bond strength to the steel plate and gives an indirect indication of the adhesive strength of the binder to the aggregate in the mix. ASTM D 4541 – Standard Test for Pull-Off Strength of Coatings Using Portable Adhesion Testers.
Evaluation of various standards of adhesion properties between fused-layer-modeling parts and injection molded parts
Published in The Journal of Adhesion, 2020
A. Richter, F. Fischer, K. Dilger
In contrast to the peel test, the pull-off test is intended to test the adhesive strength under mechanical tensile load. The material combination is an ABS – PETG connection. For this modified test series, no constructive layer adjustment is performed as seen in the peel test. Here the pure adhesive strength of the connection partners is tested. To classify the quality of the direct joining process, in addition to the application of melted filament, pretreatment of the surface is also studied more closely.