Loading documents preview...
ROAD NOTE 31 •
Issued by TRL (Transport Research Laboratory-UK) in 1993
•
A Guide to the Structural Design of Bitumen-Surface Roads in Trofical and Sub-Trofical Countries.
•
Design are presented in the form of a structural cataloque.
•
Traffic classes considere : T1 =
•
T5
= 3.0 – 6.0
T2 = 0.3 – 0.7
T6
= 6.0 – 10
T3 = 0.7 – 1.5
T7
= 10 – 17
T4 = 1.5 – 3.0
T8
= 17 – 30
S4
=
S2 = 3 – 4
S5
= 15 – 29
S3 = 5 – 7
S6
=
Subgrade strength classes : S1 = < 2
•
(106 ESAL)
< 0.3
(CBR %)
8 – 14
> 30
Designs are presented in 8 chart, each chart reprensetens a particular combinations of layer materials
Chart 1 : Granular road base + surface dressing (not applicable for traffic classes T7 and T8)
Chart 2 : Composite road base (unbound + cemented layer) + surface drressing (not applicable for traffic classes T8)
Chart 3 : Granular road base + semi-structural surfacing (50 mm of asphaltic materials) not applicable for traffic classes 7 and 8)
Chart 4 : Composite road base + semi-structural surfacing (not applicable for traffic classes 1 and 2)
Chart 5 : Granular road base + structural surfacing (100 mm to 150 mm of asphaltic) applicable only for traffic classes 6, 7 and 8)
Chart 6 : Composite road base + structural surfacing (100 mm to 150 mm of asphaltic )
Chart 7 : Bitominous road base + semi-structural surfacing (not applicable for traffic classes T1, T2 and T3) surface drressing for for traffic classes T4, 50 mm asphaltic for 5, 6, 7 and 8)
Chart 8 : Cemented road base + surface dressing (not applicable for traffic classes T9 and T8)
ROAD NOTE 29 •
Design for New road no with resurfacing and maitenance.
•
Type of pavement Flexible and rigit pavement.
•
Used nomogram 5 (flexible) and 3 (rigid). Nomogram flexible pavement : Nomogram 1 : Thickness of sub-base Nomogram 2 : Rolled asphalt (minimum thickness of surfacing and road base) Nomogram 3 : Dense macadam (minimum thickness of surfacing and road base) Nomogram 4 : Lean concrete, soil cement and cement-bound granular road base (minimum thickness of surfacing and road base) Nomogram 5 : Wet-mix and dry-bound macadan road base (minimum thickness of surfacing and road base)
Nomogram rigid pavement : Nomogram 1 : Concrete (minimun Thickness of slaps) Nomogram 2 : Reinforcement (minimum weight for slaps) Nomogram 3 : Maximun spacing of joint for reinforced concrete slaps
•
For cummulative commercial vehicle used 5 variantgrowth rate ( 3%, 4%, 5% and 6%)