Effect of cement on performance of dense graded emulsified asphalt concrete

SUMMARY Effect of Cement on Performance of Dense Graded Emulsified Asphalt Concrete Asphalt emulsion mixtures have very important economical, environmental and logistic advantages. But, they have not been used in place of hot mix concrete yet because of their performance disadvantages. Asphalt emulsion mixtures are designed gap graded in order to drainage water easily, which decreases the performance of the mixture. Besides, the mixture can be exposed to erosion in case of additional external water entrance. These problems are preventing use of asphalt emulsion mixture, but, it is researched satisfactory solutions for these. This study of emulsified asphalt concrete has been focused to solve the problems and present alternative to hot mixture. In this point, dense graded aggregate of hot mixture was selected and specimens of mixture were produced for various ratios of portland cement used instead of mineral filler. It was seen that adding of cement was provided very important increase of mixture stability after pre-research. In this connection, the subject of this study investigated as more detailed. How dense, graded mixture performance is effected with adding various cement ratios, how temperature behavior of mixture is formed and how mixture performance is effected with various ratios of residual bitumen content with cement addition is investigated detailed in this study. Performance tests as Marshall Test, Indirect Tensile Test, Water Damage Test, Static and Repeated Load Asphalt Creep Tests were carried out on specimens that were produced according to the Modified Marshall Method. In study, 349 Marshall Specimens were produced and 1770 tests were carried out on the specimens. vmSpecimens of emulsion asphalt mixtures were produced for various ratios of Portland cement from %1 to %6 is used instead of %6 mineral filler in dense graded aggregate. In order to determine effect of asphalt content with cement addition on mixture behavior, and to introduce an optimal approach between cement ratio and asphalt content in mixture design, test studies were extended for three asphalt content. Specimens were produced according to Modified Marshall Method were subjected to Indirect Tensile Test for different curing times throughout one year. And change in Resilient Modulus of mixture was investigated comparatively with hot mixture specimens were produced exactly the same aggregate grading and bitumen content equivalent to the residual binder content of the emulsion. To determine temperature sensitivity of various cement modified asphalt emulsion mixtures, specimens were subjected to Indirect Tensile Test for three temperatures (5, 25 and 40°C) for each three asphalt contents. Besides, emulsion mixture specimens were produced for various cement levels in the same conditions were subjected to Static and Repeated Asphalt Creep Tests; rutting potentials were investigated and compared with hot mixture specimens. In addition, resistance of specimens to Water Damage was tested depending on cement ratio and how emulsion mixture performance was affected with cement amount was researched. Mathematical models were established for resilient modulus and static creep deformation using results obtained from experimental studies. Resilient modulus can be estimated for untested temperatures owing to model established for resilient modulus depending on temperature variable. Results are drawn from this study are satisfactory. High performance is obtained with cement added emulsified asphalt concrete; a satisfactory solution is introduced to the most important problems of asphalt emulsion mixtures. Key Words: Asphalt Emulsion, Cement, Asphalt Cold Mix, Emulsified Asphalt Concrete, Mechanical Properties DC