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Input items consist of the following:

 

•18 input variables,

•29 input constants, and

•25 frequencies of the axle-load distribution.

 

Input Variables

 

A table with 19 input variables will be found at the Control Page, namely

 

1.Cement content, kg/m3

2.Water content, l/m3

3.Flexural strength, MPa

4.Slab thickness, mm

5.Subbase stiffness, MPa

6.Subbase thickness, mm

7.Stiffness E3, MPa

8.Thickness h3, mm

9.Stiffness E4, MPa

10.Thickness h4, mm

11.Stiffness E5, MPa

12.HV traffic growth, %p.a.

13.Speed of HV traffic, km/h

14.Contact pressure, MPa

15.Annual rainfall in mm      

16.Daily temperature cycle

17.Joint movement, mm

18.Voids extra, m

19.Initial IRI, m/km

 

For each variable there are three figures representing the practical minimum, the best estimate B, and the practical maximum. The best estimate B is multiplied by factors Min q and Max q, to obtain the practical minimum and maximum values, respectively.

 

B is the figure around which the values of a given variable occur most frequently. The user may set any of these values according to his or her best knowledge. The user must then make sure that B is a realistic figure, that all values of q are between zero and unity, and Min q is not greater than Max q.

 

The minimum, best and maximum values thus entered will be used to generate random values from an individual triangular probability distribution for each input variable.

 

 

Input Constants

 

A table with the first 29 input constants is in the lower left section of the Control Page, namely

 

1.Life period

2.Average initial daily truck traffic (ADTT0)

3.Average axles per HV

4.Loads on edge

5.Damage constant a

6.Damage exponent b

7.Ratio k1, E1/f

8.Ratio k2, ITS/f

9.Bond

10.Drainage factor

11.Erosion factor

12.Joint spacing

13.Steel diameter

14.Steel spacing

15.Aggregate crushing value

16.Aggregate type

17.Aggregate size                  

18.Cement type

19.Aggregate content

20.Fibre content

21.Fibre factor

22.Relative humidity

23.Cost of concrete

24.Cost of steel

25.Cost of subbase

26.Cost of subgrade

27.Cost of structural repairs

28.Cost of surface repairs

29.Cost of fibres      

 

The last constant, no.30, is the time t1 to the first rehabilitation. Because of its prominence among the input items, the input box for this constant is provided separately.

 

Frequencies of the Axle Load Distribution

 

The 25 frequencies of the axle-load distribution are to be entered on the Axle Loads Page. Although the frequencies can be entered individually, they are usually entered together.

 

Note: Axle load is the only input variable whose probability distribution is empirical rather than triangular.