BS EN 301-2006 pdf download.Adhesives, phenolic and aminoplastic, for load-bearing timber structures Classification and performance requirements.
This BS EN 301 establishes a classification for phenolic and aminoplastic polycondensation adhesives according to their suitability for use for load-bearing timber structures in defined climatic exposure conditions, and specifies performance requirements for such adhesives for the manufacture of load-bearing timber structures only.
The performance requirements of this standard apply to the adhesive only, not to the structure. This standard does not primarily cover the performance of adhesives for the production of wood-based panels.
This standard is primarily intended for the use of adhesive manufacturers and for the use in timber structures bonded with adhesives, to assess or control the quality of adhesives, This standard only specifies the performance of an adhesive for use in an environment corresponding to the defined conditions.
Such an adhesive meeting the requirements of this standard for its type Is adequate for use In a load- bearing structure, provided that the bonding process has been carried out according to an appropriate product standard.
2 Normative references
The following referenced documents are indispensable for the application of this European Standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 302-1, Adhesives for load-beanng timber structures – Test methods – Part 1: Determination of bond strength in longitudinal tensile shear strength
EN 302-2. Adhesives for load-bearing timber structures — Test methods — Part 2: Determination of resistance to delamination
EN 302-3, Adhesives for load-bearing timber structures — Test methods — Part 3: Determination of the effect of acid damage to wood fibres by temperature and humidity cycling on the transverse tensile strength
EN 302-4, Adhesives for load-bearing timber structures — Test methods — Part 4: Determination of the effects of wood shrinkage on the shear strength
EN 302-6. Adhesives for load-bearing timber structures — Test methods — Part 6: Determination of the conventional pressing time
EN 302-7. Adhesives for load-bearing timber structures — Test methods — Part 7: Determination of the conventional working life
3 Terms and definitions
For the purposes of this European Standard. the terms and definitions given in EN 923:2005 and the fo!owing apply.
3.1
polycondensation adhesive
adhesive mixture, made from a resin formed by a polymerisahon reaction involving the elimination of water, usually with a hardener
NOTE Such adhesives usually also contain extenders andior fillers.
3.2
phenolic resin
thermosetting synthetic resin derived from a condensation reaction of a phenol with an aldehyde
3.3
aminoplastic resin
thermosetting synthetic resin derived from a condensation reaction of the —NH groups or —NH2 groups of amines or amides with aldehydes
4 Classification
Adhesives fof structural purposes shall produce joints of such strength and durability that the Integrity of the bond is maintained in the assigned service class throughout the expected life of the structure.
Two types of adhesive. I and II, are classified according to their suitability for use in the climatic conditions given In Table 1.
5 Requirements
5.1 General
Adhesives complying with this European Standard shall meet the performance requirements specifIed in 5.2 to 5.5 when tested In accordance with the following test methods from EN 302 Parts 1 to 4.
a) The tensile shear test (see 5.2 and EN 302-1) using bonded test pieces made from beech (Fagus sylvatica L.).
b) The delamination test (see 5.3 and EN 302-2) on bonded test pieces made from spruce (Picea abies L.). If the adhesive is specifically claimed to be suitable for use with wood from hardwood species and/or specially treated wood, then the adhesive shall also be tested on bonded test pieces made from that species or wood treated in that way.
c) The fibre damage test (see 5.4 and EN 302-3) on bonded test pieces made from spruce (Picea abies L.).
d) The shrinkage stress test (see 55 and EN 302-4) on bonded test pieces made from spruce (Picea abves L).
All these tests are to be carried out with ready for use glue mixes. i.e. adhesive and hardener mixed just before application. These adhesives should be applied according to the manufacturers instructions.
In the case of separate application of adhesive and hardener, the delamination test (EN 302-2) and the fibre damage test (EN 302-3) shall in addition be performed with separate spread of adhesive and hardener.
5.2 Tensile shear test
Mean tensile shear failing strengths (N/mm2). measured in accordance with EN 302-1. of close contact joints (approximately 0,1 mm) and gap joints (1,0 ± 0,1 mm) in beech test pieces treated as specified in EN 302-1 shall be not less than those given in Table 2.BS EN 301-2006 pdf download.