CSA A231.1:19 Precast concrete paving slabs/Precast concrete pavers.
7.1.3 Air curing
Air curing shall be carried out in lab conditions at 23 ± 5 C and a relative humidity of 50 ± 15%.
7.2 Dimensional accuracy test
7.2.1 General
All specimens within a set shall be tested for dimensional accuracy.
7.2.2 Test procedure
For height and warpage measurements, each specimen shall be inverted on a flat surface. The flat surface shall be at least 25 mm greater than the specimen size in all directions. The height of the specimen shall be taken at four points approximately the centre of each side. The measurement shall be taken within 5 mm from any edge of the specimen, excluding all chamfered areas. Height measurements shall be calculated as the distance between the flat surface and the top of the specimens. The height of the product shall be calculated as the average of the four values. Concave or convex warpage measurements shall be taken at the centre and compared to the average of the four values taken from the perimeter, adjusting for any intentional profiles in the surface.
Plan measurements shall be based on the manufacturer’s mould drawings and dimensions. Spacer bars, if applicable, shall not be measured, but a measurement adjacent to the spacer bars may be taken. The measurements shall be taken at a height equal to the midpoint of the nominal thickness of the specimen. For slabs with heavily textured surface, dummy joints, or grooves, the minimum thickness shall be measured at three points along the anticipated fracture line and averaged.
The reporting of these measurements, which shall be accurate within ± 0.1 mm for height and ± 0.5 mm for length and width, shall be included in the reports for flexural strength (see Clause 7.3.4) and de-icing salts freeze-thaw durability (see Clause 7.4).
7.3 Flexural strength test
7.3.1 General
Three specimens from the set shall be tested for flexural strength. Each specimen shall be tested with the wearing surface facing upward in the testing machine. The load shall be uniformly applied without shock, starting from zero, at a rate not exceeding 18 N/s for each 100 mm of width tested, until the specimen fails. The accuracy of the applied load shall be ± 2%. Size of test specimens
Test specimens shall be full size unless the test specimens do not fit into the testing machine. If full size
specimens cannot be tested, test specimens shall be cut to have
a) a cross section about any principal axis that is a rectangle;
b) a minimum width of 250 mm; and
c) a minimum length equal to three times the specimen thickness, d, plus 50 mm, but not less than 250 mm.CSA A231.1 pdf download.