Testing Of Bricks: Dimension Test (IS: 1077)

Testing Of Bricks: Dimension Test (IS: 1077)

About fifty pieces of bricks are taken at random from different parts of the stack to perform various tests. For the purpose of sampling, a lot should contain maximum of 50,000 bricks. The number of bricks selected for forming a sample are as per Table 2.3, (IS: 5454). The scale of sampling for physical characteristics is given in Table 2.4.

Table 2. Scale of Sampling and Permissible Number of Defectives for Visual and Dimensional Characteristics

Note: In case the lot contains 2000 or less bricks, the sampling shall be subject to agreement between the purchaser and supplier.

Table 3. Scale of Sampling for Physical Characteristics

Note: In case the lot contains 2000 or less bricks, the sampling shall be subject to agreement between the purchaser and supplier.

Dimension Test (IS: 1077): 20 pieces out of selected pieces (Table) are taken and are laid flat as shown in Fig. 16.

The tolerances (Section ) on the sizes of bricks are fixed by giving maximum and minimum dimensions, not on individual bricks but on batches of 20 bricks chosen at random.

It follows from this method of measurement that batches are likely to contain, bricks outside the prescribed limit of tolerance. Such lots should be rejected to avoid complaints about the variation of perpends.