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

519.3.1.3 Aggregate grading and binder content:
(i)When tested in accordance with IS: 2386 Part 1 (wet sieving method) the combined aggregate
grading f or the particular mixture shall fall within the limits shown in Table 500-40.
(ii)The grade and range of quantity of emulsion are also indicated in this table.
(iii)The actual quantity of emulsion to be used shall be approved by the Engineer in charge after
seeing the results of trial mixes made in the laboratory.
Nominal Size (mm)
and Type of Macadam
TABLE 500-40.
COMPOSITION OF RECIPE MIXES
14 Open
40 Open
40 Single
textured
textured base
course
wearing
course
course
6 Medium
textured
wearing
course
Fine
coated
Allowable
75-100 75-100 31-50 21-30 15-20
Thickness (mm)
IS Sieve Size mm
Cumulative % by weight of total aggregate passing
45 100 100 - - -
37.5 90-100 90-100 - - -
26.5 55-90 55-85 - - -
19 100 - -
13.2 35-55 15-35 90-100 - -
9.5 55-75 100 -
6.3 20-30 25-45 90-100 100
3.35 10-20 0-10 15-25 45-65 -
2.36 - - - - 75-100
1.18 - - - 10-30 -
0.60 - - - - 30-55
0.30 2-10 - - - -
0.15 - - - - 10-25
0.075 - - 2-6 2-8 5-15
Emulsion grade and quantity
Generally A2– 57 (4) OR A2 – 50 (4)
Under some
circumstances
Quantity (1) 55 45 TO 70 TO 85 TO 100 to (2)(3)
liters/stone 70 65 90 100 120
Note:
(l) For pricing purposes the lower quantity in these ranges should be assumed
(2) With coarser grading quantity may sometimes be reduced to 80 lilres/stonne and
finer grading it may sometimes be increased up to 135 litres/stonne.
(3) Use 0 - 70 litres/stonne of water as necessary.
(4) A2-50 and A2-57 are British grades of emulsion and their grading system is explained in the
Manual.
519.3.2. Construction operations
519.3.2.1. Weather and seasonal limitations:
(i)Construction with cold mix must not undertaken when ambient temperatures below 10°C are
expected of generally when poor weather is predicted.
(ii)Bitumen emulsion and cutbacks depend on the evaporation of water and/or solvent for the
development of their curing and adhesive characteristics.
(iii)Cold weather, rain, and high humidity slow down the rate of curing.
(iv)Extra manipulation may be required to remove volatiles in cool or humid conditions. Wind
increases the rate of evaporation.