چكيده به لاتين
Abstract
Nowadays, one of the problems in the road construction industry is due to fatigue behavior, rutting and moisture sensitivity of pavement surface, which has been proposed and implemented many solution to improve these features. In this research, we have tried to achieve better results with the use of additives such as electric arc furnace dust and polyvinyle chloride powder in order to improve the mentioned behaviors. On the other hand, environmental problems are one of the most controversial issues of today's societies. electric arc furnaces dust are one of the most dangerous products of the steel industry, which mainly include a range of heavy metals such as zinc, cobalt, copper, lead, cadmium and iron. The results of the leak test or TCLP show that the amount of these elements has exceeded the standard. Also according to the physical and chemical characteristics of this dust, it is classified as one of the most hazardous waste that has risen on a global scale, based on increasing steel production and scrap recycling facilities. One of the goals of this research is to solve the problem of these hazardous materials, one of these solution is the use of these materials in the road construction industry. These wast product are mixed with asphalt bitumen and improve the properties of asphalt mixes, as well as the results of the leak test at this stage, shows that the presence of this material in asphalt does not pose any risk. In this study, polyvinyl chloride powder, a polymeric material, is among the top three polymers in the world, which has been added to improve the asphalt properties, and in the end, it has been compared in various experiments with a mixture of additive flyash and control mixtures. All of these additives, by 5% weight of bitumen in the mixture for Marshall tests, indirect tensil strength to evaluate the moisture sensitivity of the mixture, resilient modulus test, dynamic creep test and also SEM and FTIR tests on Pure bitumen and bitumen containing additive, was used. Also in this research were used 5 and 10% of polyvinyl chloride powder and electric arc furnace dust and both of them in one mixture in an equal way to perform SHRP test for bitumen. The use of electric arc furnace dust and polyvinyl chloride powder as bituminous modifier has shown that the moisture sensitivity of the mixture decreases. It also causes the amount of modulus to be displaced within the standard range and increases the dynamic creep that expresses the increase in the strength of the mixture against permanent deformations. The results of the SEM tests also indicate homogeneous mixing of bitumen and additive. The FTIR test also shows changes in the chemical structure of the bitumen after adding the additive. The results of MSCR and LAS tests also show that the addition of polyvinyl chloride powder and electric arc furnace dust improves rutting and fatigue behavior of asphalt bitumen. All experiments indicate good performance of the mixture containing an electric arc furnace dust and polyvinyl chloride powder.
KEY WORDS: Rutting and fatigue, EAFD, PVC, SEM and FTIR test, SHRP test
