Application of Fly Ash in ASHphalt Concrete : from Challenges to Opportunities
Fly ash has been effectively used for many years in producing high performance concrete, with limited use in asphalt pavements. This is possibly because the performance benefits that fly ash provides to asphalt mixtures are under-investigated. The reported research investigated the interaction of fly ash with different types of asphalt binders and documented important improvements found in the critical properties of asphalt. Microstructural investigation demonstrated in previous work, that crack-arresting behavior was successfully induced by evenly distributed fly ash particles within the bitumen matrix. Investigation of the rheological performance of blends of asphalt binders with different types of ash using dynamic shear rheometer confirmed the feasibility of using fly ash to improve the performance of asphalt
IMPROVED ASPHALT AGGREGATE MIX PROPERTIES BY PORTLAND CEMENT MODIFICATION
The objective of this study is to investigate the effect of the use of Portland Cement in place of normal filler on mixture characteristics and laboratory fatigue performance of dense graded asphalt-aggregate mixtures. First of all, a dense bituminous mixture was selected as a base mixture, composed of calcareous aggregate and 60/70 penetration asphalt. At the optimum asphalt content, Marshall tests were conducted on specimens with and without Portland cement. It is observed that there was a definite increase in Marshall stabilities when Portland Cement was used in place of normal filler. By the use of UMATTA tester (a type of Nottingham Asphalt Tester), indirect fatigue tests were performed on a series of specimens. In order to have comparative results, the test conditions were kept constant for both type of specimens, namely with normal filler and with Portland cement. The analysis of elastic and permanent strains have shown that the laboratory fatigue life of the specimens with Portland Cement is considerably higher than that of the specimens with normal filler. For the covering abstract see ITRD E107185.
Technology meets the challenge of cullet processing
Quality is a major concern for glassmakers when it comes to melting post-consumer cullet, but the latest processing lines are providing more reliable separation of contaminants than ever before.