PAD - LGED

Table 9.2: Geometric Dimension of UNR
Carriageway width
3.0 m
Total shoulder width (each side) 1.25 m
Carriageway camber 3%
Shoulder camber 5%
Maximum gradient 3%
Road crest width
5.5 m
REHABILITATION AND MAINTENANCE (RPM)
5. The LGED Rural Road Design Manual and Road Maintenance Manual, are generally
applicable to rehabilitation and maintenance of UZRs and UNRs under RTIP-II. Maintenance
work includes filling pot hole and depressions, restoring hard shoulder and placing overlay
ranging in thickness from 100mm to 150mm. It also includes sealing the surface of a thickness of
about 7mm and 12mm. The basic principle of this intervention is to restore the geometric
standard of the roads as per defined UZR and UNR standards as mentioned earlier. However, the
crest width, pavement width or embankment cross section will not be changed. Therefore, there
will not be any land acquisition involved.
PAVEMENT DESIGN
6. The typical asphalting pavement construction, based on a flexible pavement concept,
consisted of the following:
Upazila Road (UZR)
Table 9.3: UZR Road Design
Layer Thickness Materials
Surfacing 25 mm and 40 mm Asphalt (crushed stone/bitumen)
Base Course 150 mm Crushed brick/sand mixture
Sub-base 150 mm Crushed brick/sand mixture
Improved Sub-grade 250 mm Sand
7. The hard shoulder will be constructed as an extension of base course.
Union Road (UR)
Table 9.4: UR Road Design
Layer Thickness Materials
Surfacing 25 mm Asphalt (crushed stone/bitumen
Base Course 150 mm Crushed brick/sand mixture
Sub-base 150 mm Crushed brick/sand mixture
Improved sub-grade 200 mm Sand
8. 25 mm surfacing was selected as it was successfully implemented in RTIP-I, RDP-11 and
RDP-7. The use of crushed brick in the pavement layers is common in Bangladesh because of
the lack of stone in the country. Crushed stone base course could be used in a few roads in Sylhet
region as stone is available in the Sylhet region. Crushed stone is, however, a requirement in
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