Quality Assurance Handbook for Rural Roads Volume-I - pmgsy

3. Section-400
5.3 Quality Control Checks by AE/EE
The quality control checks to be carried out by the AE/EE are indicated in Table 405.8.
TABLE 405.8 : QUALITY CONTROL CHECKS BY AE/EE
Stage Test Frequency Designation of
Inspecting Officer
1. Top of the (i) Volumetric analysis (a) One test for each 200 m length of the layer. AE
Finished WBM
Layer
(b) One test for each 500 m length of the layer. EE
(ii) Plasticity Index One test for each 500 m length of the layer
(mean of two tests)
AE
(iii) Surface Regularity
and Transverse
Profile
Random Checking EE
C Do’s and Don’ts
1. Check aggregates for Soundness test when water
absorption is more than 2 percent.
2. Soft aggregate should be tested for wet aggregate
impact value.
3. Construct shoulders simultaneously along with
WBM layers.
4. Use inverted choke over fine grained soil sub-grade.
5. Remove BT surface before WBM is laid on an existing
black top road.
6. Remove defective macadam to full depth and replace
by fresh material and recompact.
406. WET MIX MACADAM BASE
A Methodology
Do’s Don’ts
1. Do not use any material derived from rocks e.g.
phyllites, shales or slates.
2. Do not use local soil and clayey material as screenings
or binding material unless it meats the requirements
of PI mentioned in para B1 (iii).
3. Do not use binding material if screenings are of
crushable type.
4. Do not spread coarse aggregate more than 3 days in
advance of any subsequent operations.
5. Do not roll if sub-grade is soft or yielding or causes a
wave like motion while rolling.
6. Do not lay WBM layer on lime treated sub-base until
it has attained its strength.
7. Do not use screenings to make up depressions.
8. Do not allow traffic till WBM is fully set.
1. The surface to receive Wet Mix Macadam (WMM) shall be prepared as per sub-section 405.
2. WMM shall be prepared in an approved mixing plant with mixing arrangements like the pug mill
or pan type mixer of concrete batching plant. For small quantities of WMM, the Engineer may
permit the use of concrete mixers.
3. Optimum moisture for mixing shall be determined in accordance with IS:2720 (Part 7) after replacing
the aggregate fraction retained on 22.4 mm sieve with material of 4.75 mm to 22.4 mm size.
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