CT4860 STRUCTURAL DESIGN OF PAVEMENTS

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on motorways where it is government policy to apply ‘silent roads’ which means in practice a wearing course of porous asphalt (‘ZOAB’). The fine cracks in the reinforced concrete pavement prevent ZOAB for reflective cracking. Below the reinforced concrete pavement a 50 to 60 mm thick asphalt layer is applied. The reasons for this are: - the asphalt layer has a very good resistance against erosion which is essential for a good structural behaviour of the concrete pavement; - the asphalt layer provides a very uniform friction with the overlying reinforced concrete layer which is favorable for the development of a regular pattern of fine cracks in the concrete layer; - the surface of the asphalt layer is very even which results in a constant thickness of the concrete later and that is also favorable for the development of a regular pattern of fine cracks in the concrete layer; - in the case that a cement-bound base is applied the asphalt layer acts as an anti-reflective layer. Figure 4 shows the top view of the reinforced concrete pavement on one carriageway of a motorway. The 12 m wide carriageway contains 2 traffic lanes and an emergency lane. Figure 4. Top view of a carriageway of a motorway with a reinforced concrete pavement (8). 16
The pavement was constructed in two strips. One strip carries the left (fast) traffic lane and the second strip carries the right (slow) traffic lane plus the emergency lane. The longitudinal construction joint between these two strips is located just left of the heavily loaded right traffic lane. In the construction joint ty bars (diameter Ø = 20 mm, length = 800 mm) are applied at a mutual distance of 1.67 m. Figure 5 shows in more detail the longitudinal construction joint with the longitudinal and transverse reinforcement and the ty bars. Figure 5. Longitudinal construction joint in reinforced concrete pavement (8). The second concrete strip in figure 4 has a width of 7.825 m. This is far more than 5 m and therefore a longitudinal contraction joint has to be applied. In such a contraction joint in reinforced concrete pavements no ty bars are necessary (compare figure 3) as the present transverse reinforcement already fulfills the function of the ty bars. 17
Page 1: CT4860 STRUCTURAL DESIGN OF PAVEMEN
Page 5 and 6: Table of Contents 1. INTRODUCTION 3
Page 7 and 8: 1. INTRODUCTION In many countries c
Page 9 and 10: main part of the traffic loading. T
Page 11 and 12: Well graded crusher run, (high qual
Page 13 and 14: Property Sandcement Lean concrete A
Page 15 and 16: In the Dutch design method for conc
Page 17 and 18: 2.6 Layout of concrete pavement str
Page 19: widened (e.g. to 8 mm) to a certain
Page 23 and 24: p = ground pressure (N/mm 2 ) on to
Page 25 and 26: Lightweight fill material Density (
Page 27 and 28: Example Sand subgrade: ko = 0.045 N
Page 29 and 30: Figure 10. Mean distribution (%) of
Page 31 and 32: 2. Directly besides the central par
Page 33 and 34: where: h = thickness (mm) of the co
Page 35 and 36: Positive temperature gradient ∆t
Page 37 and 38: There exist a lot of (modified) Wes
Page 39 and 40: P = 50 kN = 50000 N p = 0.7 N/mm²
Page 41 and 42: Figure 15. Influence chart of Picke
Page 43 and 44: Figure 17. Influence chart of Picke
Page 45 and 46: 2 Ed I d S d = (36) 2 3 1 + ( 1 +
Page 47 and 48: slab wu = deflection (mm) at the jo
Page 49 and 50: Example L = 4.5 m = 4500 mm k = 0.1
Page 51 and 52: Figure 22. Factor F as a function o
Page 53 and 54: Example In this section an example
Page 55 and 56: Table 10 clearly shows that in the
Page 57 and 58: For instance, on the basis of numer
Page 59 and 60: Although the increase of the flexur
Page 61 and 62: 4. DESIGN METHODS FOR CONCRETE PAVE
Page 63 and 64: Figure 28. AASHTO design chart for
Page 65 and 66: 4.2.3 The BDS-method The British de
Page 67 and 68: Figure 32. Additional plain concret
Page 69 and 70: of the concrete layer. Figure 34 sh
Page 71 and 72:
where: nij = predicted number of re
Page 73 and 74:
5. DUTCH DESIGN METHOD FOR CONCRETE
Page 75 and 76:
Only the technical aspects of the o
Page 77 and 78:
2 ' ⎛ ⎞ L σ = 0.85 σ”t = 0.
Page 79 and 80:
5.3 Revised design method In the ea
Page 81 and 82:
Therefore in the revised method the
Page 83 and 84:
The tensile flexural stress at the
Page 85 and 86:
w l = 4.8 e -0.35.log Neq (74) The
Page 87 and 88:
Axle load group (kN) Number of carr
Page 89 and 90:
5.4.3 Climate In the years 2000 and
Page 91 and 92:
- W according to equation 81a at pr
Page 93 and 94:
5.4.8 Thickness plain/reinforced co
Page 95 and 96:
W = load transfer at longitudinal e
Page 97 and 98:
‘reference temperature’ at the
Page 99 and 100:
The central tensile force N in the
Page 101 and 102:
σs,cr = tensile stress in reinforc
Page 103 and 104:
In the Dutch design method for conc
Page 105 and 106:
10% 5% reference 5% 10% smaller sma
Page 107 and 108:
13. Houben, L.J.M. Finite element a
Page 109 and 110:
31. Guide for the Standardisation o
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CT4860 STRUCTURAL DESIGN OF PAVEMENTS

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