water bound macadam road

road constructed by using bitumen

1. CONTENT INTRODUCTION ROAD LAYERSTEST BITUMINOUS ROAD CONSTRUCTION MACHINERIES USE IN ROAD PAVEMENT CONCLUSION

2. INTRODUCTION TO BITUMINOUS ROAD Bituminous road is a road constructed by using bitumen. It is also called flexible pavement road. Because it changes its shape according to nature of load and sub base. . A road or pavement is a structure consisting of superimposed of processed material above the natural soil sub-grade, whose primary function is to distribute the applied vehicle loads to the sub-grade. . This type of pavement has four layers, namely, Sub-grade (bottom layer), sub-base, base, and wearing surface (top most).

3. -:- ROAD LAYERS -:- SUB GRADE LAYER -: The sub grade is the layer of naturally occur- ring material or the fill material the road is built upon. . The strength of the subgrade layer is measured using the CBR test. 2. CAPPING LAYER:- When the California Bearing Ratio (CBR) of the sub grade is than 5 %, if is normal to require a suitable capping layer of low cost material. .This capping layer is usually a granular type material designed provide a working platform on which sub-grade construction can proceed with minimum interruption from wet weather.

4. 3 . SUB BASE LAYER:- This particular layer in road pavement construction. . The primary function of sub base layer are - . Improve drainage . Minimize frost action damage. . Provide a working platform for construction. . The material used in this layer - . Granular Sub base (GSB) . Cement bound material

5. 4. ROAD BASE (BASE) -:- The road base is the main load-bearing, load, load spreading layer. In road structure usually 100 mm or more thick depending on the loading of the traffic for which the road is designed. .The road base is usually a bituminous material, dense bitumen macadam (asphalt concrete) or hot rolled asphalt. 5. BINDER COURSE -:- This is the layer of material below the surface course and above road base. .The base course (binder course) is a load spreading layer, spreading the load imposed on the wearing course (surface course) over a wider area of the road base.

6. 6 . WEARING COURSE OR SURFACE COURSE The wearing course is top layer of the road pavement and is designed - .To be impervious to the ingress (entering) of water. .To have an even running surface. .To be durable, and have a high resistance to skidding, and.To be chosen so as not to deform the weight of traffic.

7. SOME OTHER LAYERS- SEAL COAT- It is a thin surface treatment used to water proof the surface and to provide skid resistance. TACK COAT -It is very light application of asphalt , usually asphalt emulsion diluted with water .it provide proper bonding between two layer of binder course and must be thin ,uniformly cover the entire surface ,and set very fast. PRIME COAT -It is an application of low viscous cutback bitumen to an absorbent surface like granular bases on which binder layer is placed. Unlike tack coat, prime coat penetrates into the layer below, plugs the voids, and forms a water tight surface.

8. TEST THE MARSHALL STABILITY OF BITUMINOUS MIXTURE This test is done to determine the Marshall Stability of bituminous mixture as per ASTM D 1559 . The principle of this test is that marshal Stability is the resistance to plastic flow of cylindrical specimen of bituminous mixture loaded on the lateral surface .it is the load carrying capacity of the mix at 60'c and is measured in kg. The apparatus needed to determine Marshall Stability of bituminous mixture is – Marshall stability apparatus Balance and water bath

9. BITUMINOUS ROAD CONSTRUCTIONS STEPS 1. Preparation of base W.B.M. base As base material of W.B.M. Road; stone ballast, concrete 10-15cm layer are used. For bonding between concrete slab & W.B.M. used 1:2 cement wash on W.B.M. Granular medium material layer 10-15cm composite layer of sand, used for better drainage Facilities 2. Application of Tuck Coat It is desirable to lay AC layer over a bituminous base or binder course. A tack coat of bitumen is applied at 6.0 to 7.5 kg per 10 sq. Area, this quantity may be increased to 7.5 to 10 kg for no bituminous base.

10. 3. Preparation and placing of Premix The premix is prepared in a hot mix plant of a required capacity with the desired quality control. The bitumen may be heated up to 150 – 177 deg C The aggregate temperature should not differ by over 14 dig C from the binder temperature. The hot mixed material is collected from the mixture by the transporters, carried to the location is spread by a mechanical paver at a temperature of 121 to 163 dig C. the camber and the thickness of the layer are accurately verified . The control of the temperatures during the mixing and the compaction are of great significance in the strength of the resulting pavement structure

11. 4. Rolling A mix after it is placed on the base course is thoroughly compacted by rolling at a speed not more than 5km per hour. The initial or break down rolling is done by 8 to 12 tonnes roller and the intermediate rolling is done with a fixed wheel pneumatic roller of 15 to 30 tonnes The wheels of the roller are kept damp with water. The number of passes required depends on the thickness of the layer. In warm weather rolling on the next day, helps to increase the density if the initial rolling was not adequate. The final rolling or finishing is done by 8 to 10 tonne tandem roller.

12. 5. Quality control of bituminous concrete construction The routine checks are carried out at site to ensure the quality of the resulting pavement mixture and the pavement surface. Periodical checks are made for Aggregate grading Grade of bitumen Temperature of aggregate Temperature of paving mix during mixing and compaction.

13. Finished surface: 7. Open to traffic Road is open to traffic as soon as bitumen gets cooled to its surrounding temperature

14. MACHINERIES FOR THE PAVEMENT OF THE ROAD ROLLERS DOZERS GRADERS PLAT COMPACTOR PLANERS ASPHALT PAVERS TANDOM VIBRATORY ROLLER PAVER BITUMEN SPRAYER MILLERS ASPHALT SPLITTING MACHINE

15. CONCLUSION As the population is increasing day by day we need to improve our roads for beteer efiiciency in transportation.And the roads are to be constructed by keeping in mind the future aspects.this road is been construction to full fill the requirements of road users.all environment effects,vehicular characteristics,human characteristics are taken into account.all the tab tests and field test are conducted as per IRC guidelines.MORT &H specifications are used for laying out pavement.

16. REFERENCES Ministry of road transport and highways,”specifications for road and bridge works”  IRC 37-2001 guidelines for the design of flexible pavem,ents . Highways Engineering by S.K.KHANNA &C.E.G JUSTO &A.VEERARAGAVAN. IRC,, Geometric of roads,Indian road congress 1966.