Two separate sections in TR 34 3rd Edition address the question of surface regularity within aisles of an industrial floor slab where guided materials handling equipment (MHE) is to be used.
Table 4.3: Permissible limits on Properties I, II and III in defined-movement areas.
|Floor Classification||MHE lift height||Property I||Property II||Property III|
|Wheel track up to 1.5 m||Wheel track over 1.5 m|
|Superflat (SF)||Over 13 m||0.75||1.0||1.0||1.5||1.5||2.5||2.0||3.0|
|Category 1||8-13 m||1.5||2.5||2.5||3.5||2.5||3.5||3.0||4.5|
|Category 2||Up to 8 m||2.5||4.0||3.25||5.0||3.5||5.0||4.0||6.0|
Table C1: Floor classification for defined movement
|Floor classification||MHE lift height ||Property Aunit ||Property B||Property Cunit||Property D|
|Transverse elevational difference unit value – mm per m of load axle length||Transverse rate of change for each 300 mm of forward travel. Fixed % of Property AMHE value||Longitudinal eleveation difference unit value – mm per m of front to rear axle length = Aunit x 1.1||Longitudinal change in elevational difference for each 300 mm of forward travel (mm) = Aunit|
|DM 1||Over 13 m||1.3||75||1.4||1.3|
|DM 2||8 to 13 m||2.0||75||2.2||2.0|
|DM 3||Up to 8 m||2.5||75||2.8||2.5|
These are designated defined movement (DM) areas. Table 4.3 of Chapter 4, and Table C1 of Appendix C, both assess the transverse and longitudinal proﬁles of the slab in defined movement areas or aisles.
While both measure the transverse characteristic, Chapter 4 only measures the longitudinal characteristics in the wheel-tracks of the outer two load wheels of the MHE over a short wavelength (i.e.300 & 600mm), whereas Appendix C also measures the elevational differences between front and rear axles.
Rear wheels are subject to the same potential effects as front wheels. Undulations may cause poor ride quality and under wheel cross-falls may cause steering problems.
In addition, where changes in elevational difference between the rear and front wheels are of sufficient magnitude, there will be longitudinal pitching or nodding effects.
Note: Face Consultants would always recommend the use of the latter Appendix C, Table C1 if bound by TR34 3rd Edition, due to the requirement to check all wheel positions.
Further information on the difference between the Chapter 4 and Appendix C can be seen in the Concrete Society Guidance Note see link below
Appendix C was based on the American F Min method of checking, and was the spring board for the current EN 15620 and the method used in the 4th Edition of TR34 in Table 3.2.
Checking for compliance with Table C1 of Appendix C.
Note: all three wheel tracks are being checked
Checking for compliance with Table 4.3 of Chapter 4.
Note: only the two outer load wheels are checked even though, in this case a 3 wheel truck is to be used.
The Concrete Society’s TR34 (4th Ed) Chapter 3
The Concrete Society’s TR34 Free Movement (3rd Ed) Chapter 4
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