Fracture mechanics interpretation of thin spray-on liner adhesion tests

Thin spray-on liners (TSLs) are relatively thin (2-5 mm) fast setting liner materials that are sprayed onto rock surfaces to support mining excavations. The adhesive strength between a TSL and a rock surface is an important property controlling the design and performance of TSL rock support systems. In this study, direct pull-off TSL adhesion tests were interpreted based on a fracture mechanics approach. An edge crack propagation equation for a generic case (nu not equal 0.5) was derived and the failure modes of TSLs were studied. It was found that the current TSL adhesion test sample geometries show confined behaviour, the failure mode of the tests are edge crack propagation. Bulk cavitation of TSLs can only occur for very compliant samples (E < 0.6 MPa). Adhesion tests done on a TSL product, Tekflex, applied on concrete substrates were examined to verify the edge crack propagation.


Creep behaviour analysis of thin spray-on liners
Güner, Doğukan; Öztürk, Hasan; Department of Mining Engineering (2020)
Thin Spray-on Liner (TSL) is a relatively thin (2–5 mm) and fast-setting liner material used by spraying onto rock surfaces to support underground excavations. Areal support materials that are sprayed onto the rock, such as shotcrete or liners, are able to generate support resistance at small rock deformations and can prevent underground rockfalls from happening in the first place. However, where large ground convergence occurs, the more flexible TSLs may provide superior support over the full range of rock...
Work of Adhesion of Thin Spray-On Liners
Öztürk, Hasan (2012-11-01)
The interface property known as work of adhesion incorporates both adhesion and effective bond width, which are two important design parameters in thin spray-on liner (TSL) support design. The value of this parameter is yet to be recognized by the mining industry and liner manufacturers. The importance of this parameter is introduced in this study. A new methodology using pull-out load-displacement data was developed to calculate the work of adhesion between a TSL and a substrate. Tests were performed using...
Structural and optoelectronic properties of sol-gel derived nickel oxide thin films
Saraç, Büşra Ekim; Durucan, Caner; Ünalan, Hüsnü Emrah; Department of Metallurgical and Materials Engineering (2017)
Nanocrystalline nickel (II) oxide (NiO) thin films were deposited on glass substrate by spin coating of sol-gel derived solutions. Thin film formation behavior and microstructural / physical properties of the films were investigated as a function of controllable processing parameters, such as thin film thickness and post deposition heat treatment (annealing temperature) in the range of 400 – 500 °C. Microstructural, morphological and optoelectronic properties of NiO films was examined by scanning electron m...
Mechanical, electrical, and melt flow properties of polyurethane elastomer/surface-modified carbon nanotube composites
Tayfun, Umit; KANBUR, YASİN; ABACI, UFUK; Guney, Hasan Yuksel; Bayramlı, Erdal (2017-06-01)
Carbon nanotube-reinforced polyurethane elastomer composites were prepared by melt-mixing. Nitric acid oxidation and silanization were applied to carbon nanotube surfaces to achieve better interfacial interactions with polyurethane elastomer. Tensile and hardness tests, differential scanning calorimetry, melt flow index test, dielectric measurements, and morphological studies of composites were reported. The best results were obtained for surface-modified carbon nanotubes containing composites with lower lo...
Strain Gradient Crystal Plasticity Approach to Modelling Micro-Plastic Flow and Localisation in Polycrystalline Materials
Simonovski, Igor; Yalçınkaya, Tuncay (2015-09-17)
Structural materials in the reactor pressure vessels are exposed to a harsh environment, resulting in a number of material degradation processes. Irradiation generates a number of point defects in the atomic structure of a material. In addition, plastic slip localization occurs on the grain level size where highly-deformed narrow bands of material appear already at the moderate strain levels. These bands are called channels or clear bands, because they are almost empty of irradiation defects, whereas the su...
Citation Formats
H. Öztürk, “Fracture mechanics interpretation of thin spray-on liner adhesion tests,” INTERNATIONAL JOURNAL OF ADHESION AND ADHESIVES, pp. 17–23, 2012, Accessed: 00, 2020. [Online]. Available: