C-3Deflection due to shrinkage

C-3.1

The deflection due to shrinkage $a_{s}$ may be computed from the following equation:

$a_{\mathrm{cs}}=k_{3} \Psi_{\mathrm{cs}} l^{2}$

where

• is a constant depending upon the support conditions,

0.5 for cantilevers,

0.125 for simply supported members,

0.086 for members continuous at one end, and

0.063 for fully continuous members.

is shrinkage curvature equal to $k_{s} \frac{\varepsilon_{c s}}{D}$

where $\varepsilon_{\mathrm{cs}}$ is the ultimate shrinkage strain of concrete (see 6.2.4),

$k_{4}=0.72 \times \frac{P_{\mathrm{i}}-P_{\mathrm{c}}}{\sqrt{P_{\mathrm{i}}}} \leq 1.0$ for $0.25 \leq P_{\mathrm{i}}-P_{\mathrm{c}}<1.0$

$=0.65 \times \frac{P_{i}-P_{c}}{\sqrt{P_{i}}} \leq 1.0$ for $P_{i}-P_{c} \geq 1.0$

Table 25 Values of Coefficient, $k_{1}$

(Clause C-2.1)

$k_{1}$ is given by

NOTE -

$k_{2}=\frac{M_{1}+M_{2}}{M_{F 1}+M_{F 2}}$

where

$M_{1}, M_{2}=$ support moments, and

$M_{F 1}, M_{F 2}=$ fixed end moments.

where $P_{\mathrm{i}}=\frac{100 A_{\mathrm{st}}}{b d}$ and $P_{\mathrm{c}}=\frac{100 A_{\mathrm{sc}}}{b d}$

and $D$ is the total depth of the section, and $l$ is the length of span.