## Jnt

l/Rd1 = 300 x 280 x 0.35 (1.6 - 0.28) x 1.2 + 40 * 628

300 x 280

This is greater than VSd, hence only minimum links are required. Assuming grade 250 reinforcement for links, EC2 Table 5.5 gives

Hence

I 3? \ 32 VRri? = 0.5 0.7 -— x — x 300 x 0.9 x 280 = 435 kN d2 I 2001 1.5

Since

200 mm spacing gives A = 132 mm2

Use R10 links at 200 mm crs. {A = 2 x 78.5 = 157 mm2)

2.5.6 Deflection

Actual span/effective depth ratio = 5000/290 = 17.2 At mid-span

650 x 290

By interpolation from NAD Table 7, modified for f = 460

Basic span/effective depth ratio = 36 Note:

This can be increased allowing for use of a larger than required steel area to

But not greater than 48/1.15 = 41.7 Inspection shows this to be unnecessary.

Allowable lid > actual lid OK

Concise Eurocode Figure A.12

NAD Table 7 Note 2

### 2.5.7 Curtailment of reinforcement

Since the bending moment diagram has not been drawn, simplified curtailment rules are needed. These are given in Section 8 of the Appendix to the Concise Eurocode.

Using the rules, the 20 mm bars in the top may be reduced to 12 mm bars at a distance from the face of support

= 0.1/ + 320 + 0.45d = 500 + 32 x 20 + 0.45 x 280 = 1266 mm from the column face

2.5.8 Reinforcement details

The reinforcement details are shown in Figure 2.10.

2.6 Columns

2.6.1 Idealization of structure

The simplification assumed for the design of the main beam is shown in Figure 2.3.

2.6.2 Analysis

Moments and column loads at each floor are taken from the analysis for the main beam given in Section 2.4.3.

2.6.3 Cover for durability and fire resistance

Nominal cover for interior columns (exposure class 1) is 20 mm. NAD

Table

Nominal cover for exterior columns (exposure class 2b) is 35 mm. Nominal cover for 1 hour fire resistance is 20 mm.

Use 20 mm (interior) and 40 mm (exterior) nominal cover to links

2.6.4 Internal column

2.6.4.1 Loading and moments at various floor levels

These are summarized in Table 2.5.

Table 2.5 Loading and moments for internal column

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