Assessment of the mechanical properties of concrete pavement containing crumb rubber of tires

The disposal of waste scrap tires is one of the most important challenges and a massive burden facing the developed countries. One of the most important method to disposal it, is using the Crump Rubber (CR) of tires in roads and structural projects. The current research focused on assessing the performance of concrete pavement contained CR. The mechanical properties of concrete were evaluated after adding 5 percentages of CR particles as 2%, 4 %, 6 %, 8% and 10 % of total weight of aggregate. The work methodology involved investigation the effect of using different methods of treatment of CR compared with untreated CR. Also, it investigated the effect of CR particles' sizes on the mechanical properties of rubberized concrete pavement. The results of study showed that the chemically treated CR can produce rubberized concrete pavement with properties closed to that of reference mix. The replacement with 2% and 4% CR gave adequate properties of pavement to be used in highway construction, while the 6% is closed to acceptable limit. The coarser particles showed better performance in terms of mechanical properties compared with the smaller particles (as replacement from sand). Chemically treatment by NaOH for CR only caused reduction in compressive strength of concrete by 7.6%, 15% and 28% while water soaking method produce more reduction in compressive strength reached up to 52.5%, 55.1% and 65.8% for the percentages of 2%,4% and 6% CR respectively.