Procedure di test per scalini di una scala

18.05.2017 18:28

Di seguito viene riporata la procedura di test per scalini di una scala riportata nella EN ISO 14122-3.

 

8.3.1 General
To verify the requirements given in 4,2, a test shall be carried out to measure the deflection on
individuai steps of a stair.
The test (see Figure 13) shall be carried out on part of the stair comprising at least two steps.
Fix the sample to the ground and supporting wall (e.g. with a block, see Figure 13) so that there is no
movement of the sample structure during testing.
Depending on the width (clear width, w, between the stringers and the supporting structure), the test is carried out with one test load (see Figure 14) or two test loads (see Figure 15).
The loads shall be applied to a rigid block (underlayment) with maximum dimensions of
100 mm x 100 mm and having no sharp edges.
The test load is represented by Formula (6):
 
FS = y x Fd (6)
where the minimum design load, Fd, is 1,5 kN and the material factor y = 1,75 for steel and aluminium.
To avoid measurement errors caused by setting effects, the tested part of a stair should be loaded first by a preload, FP = 0,25 x FS.
  
Figure 13 — Test sample — Principle
Key
1 stringer
2 step
3 rigid block for distribution the load (underlayment)
4 block for fixing
F preload, test-load
α angle of the stair

8.3.1 General

To verify the requirements given in 4,2, a test shall be carried out to measure the deflection on

individuai steps of a stair.

The test (see Figure 13) shall be carried out on part of the stair comprising at least two steps.

Fix the sample to the ground and supporting wall (e.g. with a block, see Figure 13) so that there is no

movement of the sample structure during testing.

Depending on the width (clear width, w, between the stringers and the supporting structure), the test is carried out with one test load (see Figure 14) or two test loads (see Figure 15).

The loads shall be applied to a rigid block (underlayment) with maximum dimensions of

100 mm x 100 mm and having no sharp edges.

The test load is represented by Formula (6):

 

FS = y x Fd            (6)

 

where the minimum design load, Fd, is 1,5 kN and the material factor y = 1,75 for steel and aluminium.

To avoid measurement errors caused by setting effects, the tested part of a stair should be loaded first by a preload, FP = 0,25 x FS.

 

Figure 13 — Test sample — Principle

Key

1             stringer

2             step

3             rigid block for distribution the load (underlayment)

4             block for fixing

F             preload, test-load

α             angle of the stair

 

 

Figure 14 — Test sample for w < 1 200 mm

Key

1 stringer

2 step

3 rigid block for distribution the load (underlayment)

4 block for fixing

F preload, test-load

w clear width

 

 

 

Figure 15 — Test sample for w ≥ 1200 mm

Key
1 stringer
2 step
3 rigid block for distribution the load (underlayment)
4 block for fixing
F preload, test-load
w clear width
 
 

8.3.2 Testing procedure

Place the rigid 100 mm x 100 mm block(s) 600 mm apart at the most unfavourable point/points on the step in accordance with Figure 13, Figure 14 and Figure 15).

Slowly apply the preload(s), Fp, on the rigid block(s) and hold the loads for at least one minute. After removing the load, the dial of the measuring device shall be reset to zero.

Then test loadfs), Fs, shall be applied slowly and hold at position for at least one minute. After removing the load, the permanent deflection shall not exceed 0,3 % of the span or 6 mm.

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