1985 Ed.]
Building (Construction) Regulations
CAP. 123
B 13
17. (1) Lime mortar shall be composed of stone lime or shell lime, sand or red earth mixed by volume in the proportions shown in Table III.
(2) Lime mortar with a base of shell lime shall not be used in the construction of any load bearing wall.
[Subsidiary]
Lime mortar.
TABLE III
Lime mortar
Stone lime
Shell lime
Sand
2
ī
2 to 4
1 to 3
Note: Not more than 25 per cent of the volume of sand may be replaced by an equal volume of red earth.
18. (1) Aggregate for plain concrete shall consist of sand, well-burnt brick, well-burnt tile, well-burnt clinker, stone or any other material of which the Building Authority may approve, shall be so graded as to make a sound concrete.
(2) Aggregate for reinforced concrete shall-
(a) consist of sand and crushed stone;
(b) be hard, strong and durable and reasonably clean and free from clay, organic or other harmful matter;
(c) being fine aggregate, be of such size that--
(i) at least 90 per cent by mass will pass a 5 mm mesh screen; and
(ii) not more than 15 per cent by mass will pass a 150 μm mesh;
(d) being coarse aggregate, be of such size that--
(i) not more than 10 per cent by mass will pass a 5 mm mesh/screen; and
(ii) at least 95 per cent by mass will pass a mesh of a size 6 mm less than the minimum lateral distance between reinforcing bars, or 6 mm less than the minimum cover, whichever is the smaller, or in the case of solid slabs will pass a 20 mm mesh screen; and
(e) be so graded as to make a dense concrete.
Aggregate.
L.N. 294/76.