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Investigation and Prediction Model for the Dynamic Modulus of Asphalt Emulsion Cold Recycled Mixtures Jinhai Yan, Ph.D.1; Zhixiang Zhang, Ph.D.2; Stephane Charmot, Ph.D.3; Wuyang Ding4; and Feng Li5 Abstract: The stiffness characteristics of four types of asphalt emulsion cold recycled mixtures (AECRMs) were evaluated using the simple performance test (SPT). Factors influencing the dynamic modulus and the applicability of theWitczak model were investigated. Based on the time-temperature superposition principle, the dynamic modulus jEj master curves of recycled mixtures were constructed using nonlinearleast squares regression techniques. Statistical significance on the basis of one-way analysis of variance was evaluated as a function of cement aggregate gradation, frequency, temperature, and confining pressure. The Witczak model is suitable for AECRMs and cement-treated AECRMs, and its prediction accuracy was improved by modifying the original Witczak model. The accuracy of the predicted models was evaluated on the basis of the statistical analysis. The one-way analysis of variance results indicated that the constructed master curves were consistent with the experimental test data. Frequency and temperature significantly affected the dynamic modulus, while confining pressure was not significant. Cement and aggregate gradation had a significant effect on the dynamic modulus at high temperatures or at low frequencies, while the effect was not significant at low temperatures or at high frequencies. Furthermore, the results of the statistical analysis showed that the modified and the original Witczak models resulted in a satisfactory fit between the predicted jEj results and the laboratory measured jEj data. The modified Witczak model was more accurate than the original model for AECRM. DOI: 10.1061/(ASCE)MT.1943- 5533.0001048. © 2014 American Society of Civil Engineers. Author keywords: Asphalt emulsion; Cold recycling; Dynamic modulus; Time-temperature superposition principle; Master curve; Witczak model; Mixture stiffness. elearnica.ir-Investigation_and_Prediction_Model_for_the_Dynamic_Modulus_of_Asphalt_Emuls.pdf

Effect of Residual Asphalt Content on Creep Strain of Cement Modified Emulsified Asphalt Mixtures Original Article, C20 Oruc,S., Bostancioglu,M., Yilmaz Journal. Civil Eng. Urban. 3(3):122-127 . 2013 Abstract:Objective of this paper is to determine the rutting performance of residual asphalt content on cement modified emulsified asphalt mixtures at heavy duty highways. For this purpose, emulsified asphalt specimens with dense graded aggregate were prepared according to Marshall method for emulsified asphalt-aggregate cold mixture design. The specimens were prepared in such a way that portland cement was substituted for mineral filler in an increased percent from 0 % to 6 %. In this way, three asphalt emulsion mixtures with different residual asphalt contents of 4.2 %, 5.2 %, and 6.2 % by the mass of dry aggregate were produced. Static load asphalt creep tests were performed on the specimens. Based on the experimental work, it has been reached that dense graded cement modified emulsion mixtures are of great performance in rutting compared to hot mixtures with the same aggregate grading and bitumen content. Results showed that cement acts as a secondary binder in emulsion mixture. Creep and permanent deformation resistance are all improved by portland cement addition but the resistance to creep deformation of emulsion mixture was decreased by the increase of residual asphalt content. Keywords: Asphalt Emulsion, Residual Asphalt Content, Cement, Rutting, Creep And Permanent Deformation منبع: [Hidden Content] دانلود: [Hidden Content],C3-21.pdf JCEU,C3-21.pdf