BS EN 13894-1:2003 – Products and systems for the protection and repair of concrete structures — Test methods — Determination of fatigue under dynamic loading — Part 1: During cure
1 Scope This Part of this European Standard specifies a laboratory method of testing to ascertain how dynamic loading affects strength development of structural bonding agents during curing.
2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN ISO 8501-1:2001, Preparation of steel substrates before application of paints and related products – Visual assessment of surface cleanliness – Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings (ISO 8501-1:1988).
3 Principle This Part of this European Standard uses a thick adherent shear test specimen as shown in figure 1. The test is performed by applying a dynamic tensile force along the longitudinal axis of the specimen during curing of the adhesive. Once the adhesive is cured the bonded joint is tested to failure in tension and its failure load compared with that of an unvibrated control specimen.
4 Equipment
4.1 Steel adherents and loading plate as shown in figures 1 and 2.
4.2 Grit blasting equipment.
4.3 A tension testing machine of minimum 10kN capacity capable of applying load cycles with a frequency of 2 Hz with strain control, at a strain of 150 m/m.
4.4 A tension testing machine capable of applying static loads of up to 10 kN to an accuracy of 0,1 kN.
5 Procedure
5.1 Preparation of test pieces
The bonding surfaces of the steel adherents shall be degreased using a suitable degreasing agent and then grit blasted to grade SA 2 1/2 of EN ISO 8501-1:2001. The steel surface shall then be vacuumed to remove any dust and PVC tape applied to the four butting surfaces of the adherents in order to prevent any tensile bonding. Within 24 h, mix the adhesive in accordance with the manufacturer’s instructions and apply to each of the prepared bonding surfaces such that when they are brought together a glueline thickness of (1,0 0,1) mm is achieved.
5.2 Number of test specimens The thick adherent shear test specimens are to be tested in pairs, using a loading plate as shown in figure 2. Three pairs of thick adherent shear test specimens are to be cured under dynamic load, and a further three pairs of thick adherent shear test specimens, acting as controls, are to be cured whilst stationary.
BS EN 13894-1:2003 – Products and systems for the protection and repair of concrete structures — Test methods — Determination of fatigue under dynamic loading — Part 1: During cure