Abstract : The use of packaging waste (PE) bitumen modified to improve the comprehensive performance of asphalt, while solving the problem of packaging waste (PE) recycling and asphalt performance can not meet the actual application requirements, the test measured the softening point of asphalt increased, The degree of extension, reduction of needle penetration, and theoretical analysis of the experimental results, and study of the modification mechanism of polymer PE have a very strong practical significance.
Keywords: packaging waste PE modified asphalt performance
With the development of China's packaging industry and plastics industry, plastic products have also caused pollution to the environment while benefiting people. At present, more than 60% of urban garbage is domestic garbage, and over 80% of domestic garbage is packaging waste. Waste PE in these packaging wastes again takes up a large proportion. China has made many attempts to dispose of waste plastics. Although there are some successful experiences, there are also many shortcomings. In many fields, the recycling and recycling of waste plastic products is not optimistic. Although governments at all levels have attached great importance to the problem of pollution caused by waste plastics, they have not achieved much. At the same time, the issue of resolving environmental pollution caused by waste plastics has been completely pinned on plastic products. Degradation is also very difficult, because it is necessary to ensure that the new packaging maintains the inherent characteristics of plastic, but also limited to degradation within a certain period of time, which is also a worldwide problem.
With the development of highway construction, the performance requirements for asphalt are getting higher and higher. The main problem is that there are many problems on the high-grade pavement and we must pay attention to it. The first is the problem of hot wheels and deformation. In high temperature areas, large vehicles, and overloaded and heavily loaded sections, ruts have become one of the most serious forms of potential damage to asphalt pavements. Second, asphalt pavement water damage is severe. The so-called damage of asphalt pavement is the repeated action of asphalt pavement under the condition of oil and moisture under the influence of traffic load and temperature expansion and contraction. On the one hand, moisture gradually infiltrates into the interface between asphalt and aggregate, and at the same time, due to the effect of hydrodynamic forces, the asphalt layer Gradually delaminates from the surface of the aggregate and causes pavement damage that occurs due to the loss of cohesion between aggregates. Due to this destructive effect, in the spring and rainy seasons, the intact road surface gradually appears pockmarked, loose, loose grains and even pits. This situation has already appeared on many highways and certain highways. Third, temperature cracks in asphalt pavement in cold regions are still prevalent. When the winter temperature suddenly drops, the stress relaxation of the asphalt mixture can not keep up with the increase of temperature stress, and the stiffness increases sharply. If the ultimate strength or the ultimate tensile strain of the mixture exceeds the limit strength, cracking will occur. Violent traffic accidents happen from time to time. The problem of flooding of pavements and fast aging of asphalt on roads with large voids in anti-sliding surfaces has also plagued us. Nowadays, public expectations for road safety and comfort are getting higher and higher. The road surface must have good skid resistance and there is no water fog, no glare, and low noise in wet conditions. Therefore, to study the key technology to improve the performance of asphalt concrete pavement, that is to use modified asphalt mixed filler, has become an urgent need for China's highway construction.
This topic is aimed at this situation, the use of waste polyethylene (PE) recycled after adding to the asphalt to improve the overall performance of asphalt, significantly improve the weather resistance of asphalt, so that it is specifically used for high-grade pavement. The modified asphalt is used as a new kind of paving material for paving roads. It has good durability, wear resistance, high temperature resistance to softening, low temperature resistance to cracking, and can prolong the service life of pavements. It wastes environmental pollution. The mixing of PE into asphalt can save energy and protect the environment, and at the same time it solves the problems that the recycling and utilization of packaging waste PE and the performance of asphalt can not meet the practical application requirements.
1 Materials and Experimental Methods
1.1 Materials
1) Original bitumen: The original bitumen should be pure, non-weathering, and free of harmful impurities, with good debris shape. Use 70° (Kelamayi), 100# (Lanzhou Petrochemical).
2) Packaging Waste PE Filler: The packing PE PE used for the modified asphalt should be clean and dry, and its quality should meet the specified technical requirements. This test uses recycled milk plastic bags (mainly composed of PE).
1.2 Experimental methods
The asphalt used in the research is ordinary construction asphalt. This time, 70# and 100# are used. In order to make the waste PE more easily melted in the asphalt during the mixing process, the washed milk bag is cut into small pieces for use. Determine the mixing ratio and the amount of the experiment. When mixing, the asphalt is first heated to a molten state. When the temperature reaches about 180° C., waste PE chips are added, and stirring is continued until the waste PE is completely melted in the asphalt. During the heating process, the temperature must be strictly controlled (heating temperature should be controlled between 180-200 °C). If the temperature is too high, it will lead to aging of the asphalt; if the temperature is too low, it will not be conducive to the melting of the waste Yeah, which will extend the heating time. These are not conducive to the final experimental results.
1.3 Asphalt and waste PE mix design
Waste PE accounted for 7%, 10%, and 13% of the asphalt weight ratio, respectively, for comparison.
1.4 Experimental Considerations
1) The sampling must be uniform and representative. For each sample, the required test mold should be filled once after heating, and it should not be used repeatedly. The temperature of the experimental cast must reach 160~C or more, and must be fully stirred before preparing the cast and mix.
2) When the softening point experiment is done, the sample must be heated to the full flow after the sample is poured, and the sample ring must be poured. No other method is allowed to fill the sample ring. Otherwise, the experimental result will have a large error.
3) The determination of the volume index of the blended material should be unified.
4) To ensure that the quality of the asphalt mixture is more stable, the amount of asphalt is more accurate, and the mixing must be uniform. Only the PE asphalt modifier is completely dispersed in the asphalt to fully exert its performance, and the mixture after mixing should be uniform. The construction temperature of the asphalt mixture modified by Ziye is higher, the mixing temperature is controlled at 180°C, and the remaining requirements should meet the technical requirements of the modified asphalt pavement construction specification.
(to be continued)