Asphalt Road Construction Procedure

Asphalt road construction procedure is required to lay the any asphalt road like BM, DBM, BC etc with Quality control specifications like temperature, aggregate, JMF limits. We described temperature control of asphalt mix, aggregate quality, JMF limit and frequency test on Asphalt road.
What are the specification required for laying asphalt mix.
 

QUALITY CONTROL ROLE IN ASPHALT ROAD CONSTRUCTION 

1. Temperature of Asphalt mix in Asphalt road construction procedure

 
For VG-10
ActivityTemperature
Production140 – 160 degree celcius
layingminimum 130 degree celcius
rolling minimum 80 degree celcius
For VG-20
Activity Temperature
Production 145 – 165 degree celcius
layingminimum 135 degree celcius
rollingminimum 85 degree celcius
For VG-30
Activity Temperature
Production150 – 165 degree celcius
layingminimum 140 degree celcius
rollingminimum 90 degree celcius
For VG-40
Activity Temperature
Production160 – 170 degree celcius
layingminimum 150 degree celcius
rollingminimum 100 degree celcius

2. Thickness of Asphalt mix Layer as a DBM

The thickness of single Asphalt mix layer as a Dense bituminous macadam shall be minimum 50 and maximum 100 mm.
 

3. Quality of Coarse Aggregate for Asphalt mix

Coarse aggregate, which are going to be used in Asphalt mix must be clean, hard, durable and free from dust and organic impurities.
Here we are describing important specific limits for aggregate physical strength to
be used in DBM.

Asphalt Road Construction Procedure

4. Quality of Fine Aggregate for Asphalt mix

Fine aggregate, which is going to be used in asphalt mix should be between 2.36 mm and 0.075 mm in size. It must be crushed rock not river sand. Fine aggregate shall be clean, hard, durable and free from dust and organic impurities.
Some important quality of Fine aggregates for Asphalt mix
1. Sand equivalent value shall be not less than 50.
2. Plasticity index shall not be more than 4.
 
 
 

5. Quality of Mineral Filler for Asphalt mix

As a mineral filler we can use Cement, Hydrated lime or Rock dust in Asphalt mix.
Mineral filler shall be fulfill these gradation requirement
Asphalt Road Construction Procedure
 

6. Gradation Limit for Aspahlt mix as a Dense bituminous macadam ( DBM ) in Asphalt road construction procedure

As per nominal aggregate size gradation result shall be fall in these limit –
* Nominal aggregate size is the largest sieve size on which any of the aggregate particle is retained.
** These bitumen content has given based upon 2.7 aggregate specific gravity, If you are using aggregate which has more specific gravity than 2.7 than bitumen content can be reduced proportionally.
Asphalt Road Construction Procedure, gradation limit
 
 
 

7. Requirements of the Asphalt Mix in Asphalt road construction

Asphalt Road Construction Procedure

8. Voids in Mineral Aggregate in Asphalt Mix

voids in mineral aggregate
 
 

9. Permissible Variation in Actual Mix from JMF “Job Mix Formula”

JMF limit

10. Field Density value by Extracting Core

Field density of Asphalt mix layer as a Dense bituminous macadam shall not be less than 92 % of the density we got on the date of laying based on Theoretical maximum specific gravity ( Gmm ).
 

11. Frequency Test / Control Test on DBM Asphalt Road in Asphalt road construction

 
Test DescriptionNumber of Test
Aggregate Impact value / Abrasion valueone test / 350 cum of aggregate / Source
Flakiness and Elongation Indexone test / 350 cum of aggregate / Source
Soundness test one test / Source
Water absorption testone test / Source
Sand equivalent testone test / Source
Plasticity indexone test / Source
Polished stone valueone test / Source
Mix Gradationone set of individual and mixed agg / 400 tonnes(minimum-2)
Marshal stability and void testThree test / 400 tonnes (minimum 2)
Binder contentone test / 400 tonnes (minimum 2)
Rate of spread of mixEvery 5th truck
Density of compacted layerOne test per 700 sq.m.

3 Comments

Leave a Reply

Your email address will not be published. Required fields are marked *