Quality Assurance Handbook for Rural Roads Volume-I - pmgsy
Quality Assurance Handbook for Rural Roads Volume-I - pmgsy
Quality Assurance Handbook for Rural Roads Volume-I - pmgsy
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3. Section-400<br />
4. Surface Regularity<br />
The maximum permitted difference between the lime-flyash stabilized soil subbase layer and 3 m<br />
straight edge should be 12 mm <strong>for</strong> longitudinal profile and 10 mm <strong>for</strong> cross profile.<br />
5. Minimum Compressive Strength<br />
The mix proportion should be designed to obtain a minimum unconfined compressive strength of<br />
1.5 MPa after 28 days of moist curing. The component of soil in the lime-flyash-soil mix can be<br />
omitted, provided the specified minimum strength requirement is achieved.<br />
6. <strong>Quality</strong> Control Tests<br />
<strong>Quality</strong> Control tests <strong>for</strong> Lime-Flyash Stabilized Soil Subbase and their frequency should be the<br />
same as indicated in Tables 403.2, 403.3 and 403.4 <strong>for</strong> Lime Treated Soil <strong>for</strong> Improved Subgrade/<br />
Subbase.<br />
C. Do’s And Don’ts<br />
Do’s Don’ts<br />
1. While spreading lime and flyash, ahead of mixing,<br />
take care to prevent raising of dust.<br />
2. The thickness of uncompacted layer to yield the<br />
specified compacted thickness after compaction<br />
should be determined by field trials.<br />
3. The suitability of a particular equipment <strong>for</strong><br />
pulverization of soil clods, <strong>for</strong> mixing and <strong>for</strong><br />
compaction should be verified on a test strip.<br />
4. Compaction should be completed within 3 hours of<br />
mixing or such shorter periods as may be necessary<br />
during dry weather.<br />
5. Ensure that the final surface is well closed, free from<br />
movement under compaction planes, ridges, cracks<br />
or loose material.<br />
6. All loose or segregated or otherwise defective areas<br />
on the completed surface should be made good to<br />
the full thickness of the layer and re-compacted.<br />
410. INDUSTRIAL WASTES FOR ROAD CONSTRUCTION<br />
72<br />
1. Do not carry out Lime-flyash soil stabilization when<br />
air temperature in the shade is less than 100C. 2. Do not allow any soil clods larger than 26.5 mm in size.<br />
3. Do not allow any soft yielding spots, ruts etc. on the<br />
subgrade be<strong>for</strong>e laying the subbase.<br />
4. Do not allow more than 60 minutes to elapse between<br />
the start of moist mixing and start of the compaction<br />
process.<br />
5. Do not allow the roller to bear directly on hardened or<br />
partially hardened treated material previously laid<br />
other than those what may be necessary <strong>for</strong> achieving<br />
the specified compaction at the joint.<br />
6. Do not allow traffic to ply during the curing period.<br />
This Subsection covers two commonly used industrial wastes, viz, (a) Flyash (waste material from<br />
Thermal Power Stations) in road embankment, subbase/base courses and (b) Slags (waste materials<br />
from Iron and Steel industries)<br />
A. Methodology<br />
I. Flyash (Pond Ash)<br />
1. Use in flyash embankment construction: As per Sub-section 306.<br />
2. Use in lime-flyash stabilized soil sub-base: as per Sub-section 309.<br />
3. Use in Lime-flyash bound macadam: