1956-HKRS30-8-46_Part03 — Page 17

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BUILDING (CONSTRUCTION) REGULATIONS, 1956

(b) any proportions between those specified in Tables IV and

V:

Provided that the maximum permissible compressive stress for concrete of mixes intermediate to those specified shall be ascer- tained by proportion from the maximum permissible compressive stresses for concrete of the two nearest specified mixes, such proportion being based on the ratio of the sum of the volumes of fine and coarse aggregate, measured separately, to the volume of

cement.

(4) The volume of coarse aggregate shall normally be twice the volume of the fine aggregate, but where a denser or more workable concrete can be produced by increasing the proportion of fine aggregate, the proportion of coarse aggregate may pondingly reduced.

be

corres-

(5) Notwithstanding the provisions of sub-regulations (3) and (4) where the Building Authority is of the opinion that in any particular case other proportions will produce a suitable grade of concrete, he may permit such proportions for that case.

(6) (a) Concrete designated as Grades I-V in columa 1 of Table IV and having the resistance to crushing specified for such grades in the last column of such Table shall be known as "ordinary" concrete.

(b) Concrete designated as Grades 1A-IIIA in column of Table V and having the resistance to crushing specified for such grades in the last column of such Table shall he known as "Quality A" concrete.

(7) The quantity of water used for making concrete shall not exceed that required to ensure that the concrete is uniformly mixed, can be readily placed and worked into position, and will make a sound concrete.

(8) Concrete shall-

(a) be deposited before setting has commenced and without

segregation of the materials;

(b) he adequately consolidated by tamping or any other means including vibrating which may be approved by the Building Authority;

(c) remain undisturbed after consolidation until hardened sufficiently to withstand safely any stresses to which it may be subjected;

BUILDING (CONSTRUCTION) REGULATIONS, 1956

(f) be adequately protected from the weather, from pre- mature drying, or other causes of damage until it has hardened.

TABLE IV.

Concrete fordinary) Grades 1 to V.

Devigation.

Nomtal robe.

Toval Walmar

par 112 th

of emak

Proportions of pnlu upper and

lower loui

Center

*ea. it.

awart.

***

Grade I

Grude 11

Grade III

1-2-4

71

Grade IV

1-1-4

13+

Grada V

❤

15

Compe

Mölnbennen zwenda kan innat

Le erwalleg in blu-

per se, în, efnandard

mbcleuch eu lama.

Wichla † | Within 28

ad

Fize segregate | apgregate | days after dagen after

cu. ft.

window.dogg

CL. M.

¦

វ៉

1950

2700

1700

$550

1540

2150

10 9

1100

1650

850

1256

spm of volumes of Fine and Cosrse aggregates measured separately.

TABLE V.

Concrete (Quality A) Grades IA to MITA.

Minimum restiat kaos ta vanusiaug is the per mq, în of modes) il-inch cubes,

Foliary

Toul Volume

Prapucoan at mala, opper & lovee limits

Jeniguntam

****

undar

P112

Bk of TRACE.

Coment

Fo

GALLO

Conve

Wighla

7 days

26 dayı

gle

After

uftor

I dwyn uttar

20 dayu

httar

"en, fl

emert.

20. !.

ew. ft.

mixing

Grade 1A

1-1-2

**

Grada 11A

LIT

Grade A |1-2-4

3400 5:50 5000 4500

2850 $400 2500 3750

2300

3500 2000 1000

sum of volumes of Fine and Coarse aggregates measured separately.

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