Experimental and modelling study on nonlinear time-dependent behaviour of thin spray-on liner

Güner, Doğukan
Öztürk, Hasan
Thin spray-on liners (TSLs) are fast-setting multi component polymeric materials applied on rock or coal surface with a thickness of 2-5 mm that have fairly high tensile strength, adhesion, and elongation capabilities. Compared to conventional surface support elements, TSLs with polymer content exhibit different material responses over time. As a matter of fact, the creep behaviour of TSLs under a constant load has a significance for the evaluation of the long term performances of TSLs. This paper investigates the nonlinear creep behavior of a polymer based TSL for different curing times. Experimental studies were completed to show the nonlinear time dependent response of the liner under various constant load and curing time conditions. Dogbone shape test specimens were sustained under constant loads up to 2 months of testing time for different test sets. New equations were proposed for rupture time prediction (creep rupture envelopes) which may aid support design engineers to estimate the effective permanent support time and maximum allowable strain amount of the TSL. Test results were used to construct nonlinear viscoplastic models and viscoelastic models consisting of one independent spring and multi Kelvin-Voight elements. A good agreement was obtained between model predictions and experimental values. Generated constitutive models might aid to further numerical studies in TSL literature.


Creep behaviour investigation of a thin spray-on liner
Güner, Doğukan; Öztürk, Hasan (Elsevier BV, 2018-08-01)
Thin spray-on liner (TSL) is a fast-setting multi component polymeric material applied on a rock surface with a thickness of 2-5 mm. TSLs are primarily used as an areal support element in a support system that also incorporates rock bolts. Different laboratory and field tests were performed to understand the support performance of the TSL for underground design. The research described in this paper presents laboratory studies of the tensile creep behaviour of a cement based TSL for the first time in the lit...
Obtaining soil-water characteristic curves by numerical modeling of drainage in particulate media
Sattari, A. Shoarian; Toker, Nabi Kartal (Elsevier BV, 2016-04-01)
Soil-water characteristic curve (SWCC) is widely used for obtaining mechanical and hydraulic properties of unsaturated soils, such as shear strength, deformation, permeability, and flow. An innovative approach, where a meso-scale medium is generated based on particle size distribution and void ratio of non-plastic soils, for estimating the drying SWCC is developed. With application of the finite difference and Newton-Raphson (Jacobian) approximations, the air-entry pressures of pore bodies in inter-particle...
Performance assessment of cement grout borehole plugs in basalt
Akgün, Haluk (Elsevier BV, 1994-01-01)
Flow tests have been conducted on expansive cement grout plugs with diameters of 160 mm and 200 mm, and length-to-diameter ratios of one, in boreholes in basalt blocks and in steel pipes. Two types of flow tests have been performed: pseudo-constant head tests and transient pulse tests. Hydration temperatures of cement grout plugs have been monitored in steel pipes with inside diameters ranging from 110 mm to 200 mm. During flow tests, basalt blocks have fractured, presumably due to water injection pressure,...
Thin spray-on liner adhesive strength test method and effect of liner thickness on adhesion
Öztürk, Hasan (Elsevier BV, 2010-07-01)
The adhesive strength between a thin spray-onliner(TSL) and rock is an important property controlling the designandperformanceofTSLrocksupportsystems. The advantages and disadvantages of various adhesion test methods used by the coatings, microelectronics and concrete industries with respect to TSLs are discussed. A suggested test method for TSL materials is presented, which is based on direct pull-off of an elevator bolt that is attached to a liner with strong epoxy. To interpret the test results correctly...
Analytical and experimental assessment of mechanical borehole sealing performance in rock
Akgün, Haluk (Elsevier BV, 1997-09-05)
This paper examines the bond strength of cement grout plugs cast in rock. The bond strength has been determined through push-out testing in which an axial load is applied to cement grout plugs emplaced in boreholes in welded tuff cylinders. The push-out tests have been performed as a function of borehole (plug) radius and plug length. The use of four different borehole radii and three different plug length-to-radius ratios enables the evaluation of size effects. A power law obeying strength decrease with in...
Citation Formats
D. Güner and H. Öztürk, “Experimental and modelling study on nonlinear time-dependent behaviour of thin spray-on liner,” TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY, pp. 306–316, 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/41879.