The Concrete Society’s TR34 Defined Movement, 3^rd Edition (Now superseded by 4^th Edition)

Two separate sections in TR 34 3^rd Edition address the question of surface regularity within aisles of an industrial floor slab where guided materials handling equipment (MHE) is to be used.

Click here if you would like to view the latest specification – TR34 4th Edition.

Table 4.3: Permissible limits on Properties I, II and III in defined-movement areas.

Superseded

Floor Classification	MHE lift height	Property I		Property II		Property III
						Wheel track up to 1.5 m		Wheel track over 1.5 m
		95%	100%	95%	100%	95%	100%	95%	100%
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

The floor is non-compliant if:

more than 5% of the total number of measurements in any aisle exceed the 95% property limit
any measurement in any aisle exceeds the 100% property limit, and
any point of the floor is outside ± 15mm of datum.

It is not possible to specify and impose these limits for defined movement unless the precise positions of aisles are known before construction.

Table C1: Floor classification for defined movement

Superseded

Floor classification	MHE lift height ^[1]	Property A_unit ^[2]	Property B	Property C_unit	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 A_MHE value	Longitudinal eleveation difference unit value – mm per m of front to rear axle length = A_unit x 1.1	Longitudinal change in elevational difference for each 300 mm of forward travel (mm) = A_unit
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

[1] MHE heights are the same as those given in Table 4.3.
[2] A_unit in effect, defines the floor quality and could, in principle, be used for specification purposes.

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 3^rd 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 15620:2008† and the method used in the 4^th Edition of TR34 in Table 3.2.