as thereafter been included in the Govt of Karnataka's PWD Schedule of Rates. Road life improves through improved tackiness and viscosity of the bituminous mix, thereby binding the stones more firmly together and improving the water-resistance of the mix to rain etc. For the same reason, the temperature of the mix both at the plant and at the point of lying needs to be 20°C higher than normal.
The Bruhat Bengaluru Mahanagara Palike (BBMP) has used plastic on about 600 km of roads, including many thoroughfares and arterial roads. It uses the plastic blend in at least 25% of the road-laying works, including the present project to upgrade about 45 roads in the city. The plastic model was successful on major roads in Bangalore, including
Shankar Mutt Road, K H Road, M G Road (towards Trinity Circle), J C Nagar Road, Miller's Road and Cunningham Road. The rise in bitumen costs over the past few years has also made the plastic model more cost-efficient. To top it, plastic is not recycled but buried with the roads, forever.
Aggregate of 20mm, 10 mm. Stone Dust and Lime as Filler
• 60/70,80/100grade bitumen
Waste plastic in the shredded form
i. collection of waste plastic
ii. cleaning and shredding of waste plastic
iii. mixing of shredded waste plastic, aggregate and bitumen in
central mixing plant
iv. laying of bituminous mix
a. COLLECTION OF WASTE PLASTIC:-
Waste plastic is collected from roads, garbage trucks, dumpsites or compost plants, or from school collection programs, or by purchase from rag-pickers or waste-buyers at Rs 5-6 per kg
b. CLEANING AND SHREDDING OF WASTE PLASTIC:-
Waste plastic litter in the form of thin-film carry-bags, use-and-throw cups, PET bottles, etc. these are sorted, de-dusted, washed if necessary.
Fig. cleaning process Plastic waste which is cleaned is cut into a size between 1.18mm using shredding machine as shown below
c. MIXING OF SHREDDED WASTE PLASTIC, AGGREGATE AND BITUMIN IN CENTRAL MIXING PLANT:-
The aggregate mix is heated to 1650c (as per the HRS specification) in central mixing plant. Similarly the bitumen is to be heated up to a maximum of 160°c.
The 8% of waste plastic to the weight of bitumen are added in the conveyor belt or special mechanical device is developed which will spray the plastics inside the chamber to coat the plastics effectively.
Central mixing plant helps to have better control of temperature and better mixing of this material thus helping to have a uniform coating and heated bitumen is also sprayed.
Fig. central mixing plant d. LAYING OF BITUMENOUS MIX:-
The plastics waste coated aggregate is mixed with hot bitumen and the resulted mix is used for road construction. The road laying temperature is between 1100c to 1200c. The roller used is 8-ton capacity.
I. MIX DESIGN BY MARSHALL METHOD
a) Optimum Waste Plastic Content
b) Comparison of Two Mixes
c) Volumetric properties of BC Mixes
II. PERFORMANCE STUDIES OF WASTE PLASTIC
i. Indirect Tensile Strength
ii. Rutting Test
I. MIX DESIGN BY MARSHALL METHOD:-MARSHALL TEST:-
Laboratory studies were carried out at the Centre for Transportation Engineering of Bangalore University on the possible use of the processed plastic bags as an additive in bituminous concrete mixes. The material used in this study was supplied by M/s KK Poly Flex (P) Ltd., Bangalore. The processed plastic was used as an additive with heated bitumen in different proportions (ranging from zero to 12 % by weight of bitumen) and mixed well by hand, to obtain the modified bitumen.
Auto Marshall Compactor Auto
The properties of the modified bitumen were compared with ordinary bitumen. It was observed that the penetration and ductility values of the modified bitumen decreased with the increase in proportion of the plastic additive, up to 12 % by weight. The softening point of the modified bitumen increased with the addition of plastic additive, up to 8.0 % by weight.
OPTIMUM WASTE PLASTIC CONTENT:
> Varying percentages of waste plastic by weight of bitumen was added into the heated aggregates
> Marshall specimen with varying waste plastic content was tested for