 plastic bags causes environmental pollution.
4) It mainly consists of low-density polyethylene
5) To find its utility in bituminous mixes for road construction
6) Laboratory performance studies were conducted on bituminous mixes. Laboratory studies proved that waste plastic enhances the property of the mix
7) Improvement in properties of bituminous mix provides the solution for disposal in an useful way
WASTE PLASTICS - AS BINDER AND MODIFIER:
Waste plastics (polythene carry bags, etc.) on heating soften at around 130°C. Thermo gravimetric analysis has shown that there is no gas evolution in the temperature range of 130-180°C. Moreover the softened plastics have a binding property. Hence, the molten
plastics materials can be used as a binder and/or they can be mixed with binder like bitumen to enhance their binding property. This may be a good modifier for the bitumen, used for road construction.
DIFFERENT TYPE OF WASTE PLASTIC (POLYMER) AND ITS ORIGIN:
Type of waste plastic (polymer) origin
Low density polyethylene (LDPE): High density polyethylene (HDPE): Polypropylene (PP):
Polystyrene (PS): Foamed Polystyrene:
Polyvinyl Chloride (PVC):
bags, sacks, bin lining and squeezable detergent bottles etc
bottles of pharmaceuticals, disinfectants, milk, fruit juices, bottle caps etc
bottle cap and closures, film wrapping for biscuits, microwave trays for ready-made Meals etc.
yoghurt pots, clear egg packs, bottle caps.
food trays, egg boxes, disposable cups, protective packaging etc
mineral water bottles, credit cards, toys, pipes and gutters; electrical fittings, furniture, folders and pens; medical disposables; etc
CHARACTERIZATION OF WASTE PLASTICS: THERMAL STUDY
Thermal behavior of the polymers namely PE, PP and PS is shows in Table 1.
The molten plastics waste exhibits good binding property. Various raw materials like granite stone, ceramics etc... Were coated with plastics and then molded into a stable product. On cooling, it was tested for compression and bending strengths.
Table 2. Binding Property
Percentage of plastics coating over aggregate Compression Strength ( Tonnes) Bending Strength (Kg)
10 250 325
20 270 335
25 290 350
30 320 390
The increase in the values of the compression strength and bending strength shows that the plastics can be used as a binder.
CONCEPT OF UTILISATION OF WASTE PLASTIC IN
BITUMINOUS MIXES FOR ROAD CONSTRUCTION:
This Concept of Utilization of Waste Plastic in Bituminous Mixes for Road Construction has been done since 2000 in India, They can return to the earth as beneficial additives in bitumen roads. One such technologies are reviewed below, two for waste-polymer-modified bitumen roads.
BANGALORE'S KK PROCESS:-
At the initiative of M/s K.K. Poly Flex Pvt. Ltd., a study on the possible use of the processed plastic waste bags with the bituminous mixes was carried out at the R.V. College of Engineering Bangalore. A group of students of B.E. degree course in Chemical Engineering of this college under the guidance of the concerned teaching staff carried out their final year project work for studying the possibility of using of the processed plastic bags with bitumen and bituminous mixes. As some encouraging results were reported in this study, M/s K.K. Poly Flex Pvt. Ltd. later approached the Centre for Transportation Engineering of Bangalore University with the request to carry out further research studies on the effects of using the processed plastic bags with bituminous mixes for road construction works.
In practice, such a "plastic road" laid in Bangalore (at the busy Rajarajeshwari Junction) in March 2001 as a technology demonstration for the Chief Minister, showed superior smoothness and uniformity and less rutting as compared to a plastics-free road laid at the same time, which has begun to develop "crocodile cracks". As a result, by now 25 km of "plastic roads" have been laid in Bangalore, unfortunately without another same-day plastics-free normal road. All these 25 km are performing well. The process was also approved in 2003 by the CRRI=Central Road Research Institute Delhi, and h