Repair to BT roads at Jaggayyapet Lime Stone Mines. - Vizag Steel

4
5
6
Stripping value
Soundness:
i)Lose with sodium sulphate
ii)Loss with Magnesium Sulphate
Water absorption
IS:6241
5 cycles
5 Cycles
IS:2386(Part-III)
25% Maximum
12%
18%
62% Maximum
(*) Aggregates may satisfy requirements of either of the two tests.
Note: If crushed slag is used, Clause 2.3.4 shall apply. 2.7.2.3 The aggregate for bituminous
macadam for different thickness shall conform to the grading given in Table 13.
TABLE-13
AGGREGATES FOR 50 MM COMPACTED THICKNESS OF BITUMINOUS
MACADAM
Sieve Designation (IS) Percent by weight passing the sieve
26.5 mm
22.4 mm
11.2 mm
5.6 mm
2.8 mm
90 micron
100
75-100
50-85
20-40
5-20
0-5
2.7.2.4 Proportioning of materials:
The bitumen content for premixing shall be 4 percent by weight of the total mix except
when otherwise directed by the Engineer.
The quantities of aggregates to be used shall be sufficient to yield the specified thickness
after compaction.
2.7.2.5. Variation in proportioning of materials;
The contractor shall have the responsibility for ensuring proper proportioning of materials
and producing a uniform mix. A variation in binder content +/- 0.3 percent by weight of total
mix shall, however, be permissible for individual specimens taken for quality control tests.
2.7.3. Construction Operation:
2.7.3.1 Weather and seasonal limitations:
The work of laying shall not be taken up during rainy or foggy weather or when the base
course is damp or wet, or during dust storm or when the atmospheric temperature in
shade 15oC or less.
2.7.3.2 Preparation of the base:
The base on which bituminous macadam is to be laid shall be prepared, shaped and
conditioned to the specified lines, grades and cross sections in accordance with Clause 2.4
and a priming coat where needed shall be applied in accordance with Clause 2.5 as directed
by the Engineer.
2.7.3.3 Tack coat:
A tack coat as per Clause 2.6 shall be applied over the base.
2.7.3.4 Preparation and transport of mix.
Bituminous macadam mix shall be prepared in a hot mix plant of adequate capacity and
capable to yield a mix of proper and uniform quality with thoroughly coated aggregates.
The plant may be either a weigh batch or volumetric proportioning continuous or drum mix
type.
The temperature of binder at the time of mixing shall be in the range of 150°C to 165°C
and that of the aggregate in the range of 125°C to 150°C provided that the difference in
tempera-ture between the binder and aggregate at no time exceeds 25oC.
Mixing shall be thorough to ensure that a homogeneous mixture is obtained in which all
particles of the aggregates are coated uniformly, and the discharge temperature of mix
shall be between 130°C to 160°C.
The mixture shall be transported from the mixing plant to the point of use in suitable