B 120
CAP. 123]
Building (Construction) Regulations
[Subsidiary]
[1985 Ed.
Standard
150 mm cubes.
L.N. 294/76.
Samples of concrete for making cubes.
L.N. 294/76.
Records.
where--
Στ Σ.)2 Σ(x-3)2
n
is the sum of all the individual results.
is the sum of the squares of all the individual results; is the sum of the squares of the differences between the average. X. of all the individual results and each individual result. v, in turn; and
is the number of results, which should be not less than 40 for reasonably accurate estimate of the standard deviation.
2. The resistance to crushing of concrete shall be determined by testing standard 150 mm cubes of the appropriate age made, cured and tested in accordance with the appropriate provisions of BS 1881: Parts 3 and 4: 1970 and in accordance with this Schedule.
3. (1) Samples of concrete for making test cubes shall be taken in accordance with BS 1881; Part 1: 1970.
(2) For the purpose of determining the resistance to crushing at a particular age after mixing, each works cube shall be made from a different batch of concrete.
(3) For the purpose of checking the ratio of resistances to crushing at different ages 3 cubes shall be made from the same batch of concrete for each age for which the ratio is required.
4. (1) The following information shall be recorded-
(a) identification mark of each cube:
(b) designation of concrete;
(c) brand and type of cement;
(d) types of aggregates:
(e) mix proportions;
(f) water/cement ratio:
(g) dates of moulding and testing;
(h) location after placing in the work of the concrete from which the sample was taken;
(i) number of cubes and their marks:
(j) mixer from which sample was taken (if more than 1 mixer is used);
(k) weather conditions; and
(l) curing conditions.
(2) Copies of test reports for concretes of Quality A, special mixes and designed mixes shall be submitted to the Building Authority within 21 days after testing.
(3) Test reports for concretes of ordinary quality shall be kept and made available for inspection if necessary, until at least 6 months after the completion of the building works.
Number of cubes for ordinary quality
concrete.
Standard of acceptance
for ordinary quality
concrete.
PART II
CONCRETE OF ORDINARY QUALITY
(1) Preliminary tests are not required for concrete of ordinary quality.
(a) The works resistance to crushing of concrete of ordinary quality shall be determined from sets of 3 consecutive cubes from the same grade of concrete tested at the same age.
(b) At least 1 cube should be made for each grade of concrete on each day that it is used.
6. The specified resistance to crushing for the appropriate grade shall be deemed to have been attained if the average resistance to crushing of each set of 3 consecutive cubes is not less than the specified resistance and no individual result is less than 85 per cent of the specified resistance.
Page 120
Page 121
B 120
CAP. 123]
Building (Construction) Regulations
[Subsidiary]
[1985 Ed.
Standard
150 mm cubes.
L.N. 294/76.
Samples of concrete for making cubes.
L.N. 294/76.
Records.
where--
Στ Σ.)2 Σ(x-3)2
n
is the sum of all the individual results.
is the sum of the squares of all the individual results; is the sum of the squares of the differences between the average. X. of all the individual results and each in- dividual result. v, in turn; and
is the number of results, which should be not less than 40 for reasonably accurate estimate of the standard deviation.
2. The resistance to crushing of concrete shall be determined by testing standard 150 mm cubes of the appropriate age made, cured and tested in accordance with the appropriate provisions of BS 1881: Parts 3 and 4: 1970 and in accordance with this Schedule.
3. (1) Samples of concrete for making test cubes shall be taken in accordance with BS 1881; Part 1: 1970.
(2) For the purpose of determining the resistance to crushing at a particular age after mixing, each works cube shall be made from a different batch of concrete.
(3) For the purpose of checking the ratio of resistances to crushing at different ages 3 cubes shall be made from the same batch of concrete for each age for which the ratio is required.
4. (1) The following information shall be recorded-
(a) identification mark of each cube:
(b) designation of concrete;
(c) brand and type of cement;
(d) types of aggregates:
(e) mik proportions;
(f) water/cement ratio:
(g) dates of moulding and testing;
(h) Jocation after placing in the work of the concrete from which the sample was
jaken;
(7) Inumber of cubes and their marks:
(j)] mixer from which sample was taken (if more than I mixer is used);
(k) weather conditions; and
(/) curing conditions.
(2) Copies of test reports for concretes of Quality A. special mixes and designed mixes shall be submitted to the Building Authority within 21 days after testing.
(1) Test reports for concretes of ordinary quality shall be kept and made available for inspection if necessary, until at least 6 months after the completion of the building works.
Number of cubes for ordinary quality
concrete.
Standard of acceptance
for ordinary quality
concrete.
PART II
CONCRETE OF ORDINARY QUALITY
(1) Preliminary tests are not required for concrete of ordinary quality.
(a) The works resistance to crushing of concrete of ordinary quality shall be determined from sets of 3 consecutive cubes from the same grade of concrete tested at the same age.
(b) At least I cube should be made for each grade of concrete on each day that it
is used.
6. The specified resistance to crushing for the appropriate. grade shall be deemed to have been attained if the average resistance to crushing of each set of 3 consecutive cubes is not less than the specified resistance and no individual result is less than 85 per cent of the specified resistance.
Page 120Page 121
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