1985 Ed.]
Building (Construction) Regulations
[CAP. 123
B 17
TABLE VI
Special and design concrete mixes
2
Designation
Mix proportions
Special mixes
not leaner than 45 kg cement to 360 kg total aggregate nor richer than 45 kg cement to 130 kg total aggregate
Designed mixes
not leaner than 235 kg cement per cubic metre of finished concrete nor richer than 530 kg cement per cubic metre of finished concrete
3
Minimum resistance to crushing in MPa
within 7 days after mixing---
(i) preliminary tests
15 to 34:
(ii) works tests
12 to 26
within 28 days after mixing-
(i) preliminary tests
20 to 45:
(ii) works tests
15 to 34
within 7 days after mixing
12 to 32
within 28 days after mixing-
15 to 41
Method of test
First Schedule Parts I & IV
First Schedule Parts I & V
[Subsidiary]
L.N. 294/76.
20. Reinforcement for concrete shall be--
(a) hot rolled steel bars in conformity with the appropriate provisions of B.S. 4449:1969;
(b) hard drawn mild steel wire in conformity with the appropriate provisions of B.S. 4482:1969;
(c) cold worked steel bars in conformity with the appropriate provisions of B.S. 4461:1969;
(d) steel fabric in conformity with the provisions of B.S. 4483:1969; or
(e) such other reinforcement as the Building Authority may approve as being suitable, having regard to the particular circumstances of the case.
21. All structural and rivet steel used in building shall, before fabrication--
(a) comply with either-
(i) Grade 43, B.S. 4360 relating to mild steel for general structural purposes; or
(ii) Grade 50, B.S. 4360 relating to high yield stress (welding quality) structural steel,
whichever is appropriate; or
(b) be such structural and rivet steel as the Building Authority may approve.
Reinforcement for concrete. L.N. 294/76.
Structural and rivet steel. L.N. 294/76.
L.N. 42/75.