Specification Part 3 - Road & Bridge Works - Urban Administration ...

5
6
All types of cracks with
crack width below 6mm
All types of cracks with
crack width above 6mm
coat
2nd
coat
Single coat
SAM
as interlayer
Single coat
SAM
as interlayer
8 – 10
8 – 10
10 - 12
0.103
of 5. 6mm chips
0. 10 m3
of 5.6mm chips
0.10m3
of 11.2mm chips.
7 Bitumen Impregnated
Geotextile
Note: 1 Binder quantities for bitumen impregnated geotextile shall be in the range 0.9 to 1.2
Lures/nr. Binder quantities outside this range are permitted according to the geotextile
manufacturer’s instructions and subject to the agreement of the Engineer in charge. Geotextile
shall be applied according to Clause 502.4. The surface on which the binder is to be applied shall
be dry.
522.3.4. Application of aggregates:
(i)The equipment and general procedures shall all be in accordance with the Manual for
Construction and Supervision of Bituminous Works.
(ii)Immediately after application of the modified binder, clean, dry aggregate shall be spread
uniformly on the surface.
522.3.5. Sweeping: The surface of SAMs and SAMIs shall be swept to ensure uniform spread of
aggregate and that there are no loose chips on the surface.
522.3.6. Two coat SAM or SAMI:
(i)Where a two coat SAM or SAMI is required by the Contract, the second coat shall be applied
within 90 days of the first.
522.3.7. Geotextile placement: For bitumen impregnated geotextile, the requirements of Clause
704.4.5 of the Ministry’s Specification for Road and Bridge Works (third revision) shall apply.
522.4. Opening to Traffic
(i)Traffic may be permitted over a SAM or SAMI 2 hours after rolling but the speed shall be limited
to 20 km/h, until the following day.
(ii)Speed control measures are to be approved by the Engineer in charge, prior to laying.
522.5. Surface Finish and Quality Control of Work
(a)The surface finish shall conform to the requirements of Clause 902.
(b)For control on the quality of materials supplied and the works carried out, the relevant
provisions of clause of 501.8.4.1.
522.6. Arrangements for Traffic
(i)During the period of con struction, arrangements for traffic shall be made as per direction on
Engineer in charge.
522.7. Measurement for Payment
(i)Each application of SAM, SAMI or bitumen impregnated geotextile shall be measured as
finished work, for the area specified, in square meters
.
522.8. Rate
(i)The contract unit rate for SAM, SAMI or bitumen impregnated geotextile shall be payment in
full for carrying out the required operations including full compensation for all components listed in
Clause 501.8.8.2, (i) to (xi).