1985 Ed.]
Building (Construction) Regulations
[CAP. 123
B 89
[Subsidiary]
where-Q is the total shearing force across the section;
b is the breadth of a rectangular beam or the breadth of the rib of a T-beam or L-beam; and
z is the arm of the resistance moment.
(2) (a) Where 2 or more types of shear reinforcement are used in conjunction, the total shearing resistance of the beam may be assumed to be the sum of the shearing resistances computed for each type separately
(5) The spacing of stirrups when required to resist shear-
(i) shall be not less than 8 times the diameter of the stirrups or 75 mm, whichever is the greater; and
(ii) shall not exceed a distance equal to the arm of the resistance moment.
The resistance to shear Q shall then be calculated from the following equation:
L.N. 394/76.
Q =
PsAsz
S
where-Ps is the permissible tensile stress in the shear reinforcement;
As is the cross-sectional area of the stirrup;
z is the arm of the resistance moment; and
S is the spacing of stirrups.
(c)
(i) The resistance to shear at any section of a beam, reinforced with inclined bars, may be calculated on the assumption that the inclined bars form the tension members of 1 or more single systems of lattice girders in which the concrete forms the compression members.
(ii) The shear resistance at any vertical section shall then be taken as the sum of the vertical components of the tension and compression forces cut by the section.
(iii) Care must be taken that such assumptions do not involve greater stresses in the horizontal bars than the permissible stresses.
141. (1) (a) A bar in tension shall extend from any section for a distance to the end of the bar such that the average bond stress does not exceed the permissible average bond stress given in regulation 116.
(b) The length measured from such section shall be not less than---
the bar diameter x the tensile stress in the bar
4 times the permissible average bond stress.
1 Bond and anchorage.