Quality Assurance Handbook for Rural Roads Volume-I - pmgsy

SIMPLE/HANDFEEL TESTS
600
600.1 Bricks
117
Quality Assurance Handbook for Rural Roads
ANNEX-VI
The bricks should be sound, of compact structure (as seen when broken) free from cracks and flaws.
They should be regular in shape and of uniform size (dimensional accuracy) with plane faces and sharp
edges. The colour should be uniform and of deep red or copper colour. The quality of bricks is generally
assessed by compressive strength, efflorescence, dimensional accuracy, water absorption and evenness
of baking. Some of the simple tests to fairly assess the quality of bricks are given below:
(i) In efflorescence test, a sample brick is soaked in water for 24 hours and its appearance after removal
from water, should be free from white patches, the total area not exceeding 50%. In case the
surface area exhibiting, patches exceed 50% of total area both the brick and water samples shall be
subjected to further testing for ascertaining suitability.
(ii) In water absorption test, a brick should not absorb more than 1/5 th of its dry weight after immersion
in water for 24 hours.
(iii) Bricks are considered good when clear ringing sound is heard when two bricks are struck against
each other. A sample brick should not break when dropped flat on hard ground from a height of
about 1 m.
Correct firing promotes toughness. The bricks should not be under-burnt. A well burnt brick
when scratched with a finger nail should leave no impression.
600.2 Cement-Lime (Composite) mortar
Refer to 700.2 and 800.4
700 Stone Masonry
700.1 Stones
The chief requirements of a building stone are strength, density and durability. All stones other than
those of sedimentary origin are suitable for stone masonry work. Some of the requirements and simple
tests are indicated below:
(i) The stones should be hard, tough, compact grained and of uniform texture and colour.
(ii) They should be free from cracks, decay, weathering defects like cavities, flaws, veins, sand holes
and patches of loose/soft material.
(iii) Break a stone with a hammer. The surface of a freshly broken stone should be bright, clean and
sharp and should show uniformity of texture without loose grains and be free from any dull
chalky or earthy appearance.
(iv) If a drop of dilute hydrochloric acid or sulphuric acid on a piece of stone causes effervescence, the
stone contains weathering materials.