BS EN 12390-3:2019 pdf free.Testing hardened concrete.
The load bearing surfaces of the specimen shall be moulded in the case of cube specimens or ground or capped in accordance with Annex A in the case of cylinder, core or adjusted specimens. After removal of the specimen from curing, the specimens shall be tested for strength as soon as practicable, but within 10 hours. The test facility shall be at a temperature of (20 ± 5) °C (or (25 ± 5) °C in hot climates). Where specimens are to be stored in the testing facility for more than 4 hours they shall be protected from moisture loss e.g. by covering with wet hessian or impermeable membrane.Wipe all testing machine bearing surfaces clean and remove any loose grit or other extraneous material from the surfaces of the specimen that will be in contact with the platens. Do not use packing, other than auxiliary platens or spacing blocks (see EN 12390-4) between the specimen and the platens of the testing machine. With two-column testing machines, cubic specimens should be placed with the trowelled surface not in contact with the platens and facing a column. Wipe the excess moisture from the surface of the specimen before placing in the testing machine. Position the cube specimens so that the load is applied perpendicularly to the direction of casting. Centre the specimen with respect to the lower platen to an accuracy of 1 % of the designated size of cubic, or designated diameter of cylindrical specimens. If auxiliary platens are used, align them with the top and bottom face of the specimen.Select a constant rate of loading within the range 0,6 ± 0,2 MPa/s (N/mm2•s). After the application of the initial load, which does not exceed approximately 30 % of the failure load, apply the load to the specimen without shock and increase continuously at the selected constant rate ± 10 %, until no greater load can be sustained.The initial load should be applied as close as possible to the selected rate of loading. When using manually controlled testing machines, correct any tendency for the selected rate of loading to decrease, as specimen failure is approached by appropriate adjustment of the controls. During the final stages of the test, the load rate can be affected by the failure mode of the specimen. Nevertheless every effort should be made to maintain the selected loading rate as close as possible.BS EN 12390-3 pdf download.