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Influence of using nonmaterial to reduce the moisture susceptibility of hot mix asphalt F. Moghadas Nejad a , A.R. Azarhoosh b, GH.H. Hamedi a, M.J. Azarhoosh c a Department of Civil & Environmental Engineering, Amirkabir University of Technology, Tehran 15875, Iran b Department of Civil Engineering, University of Guilan, Rasht, Iran c Department of Chemical Engineering, Amirkabir University of Technology, Tehran, Iran a b s t r a c t Moisture damage in an asphalt mixture can be defined as the loss of strength, stiffness and durability due to the presence of moisture leading to adhesive failure at the binder–aggregate interface and/or cohesive failure within the binder or binder–filler mastic. In order to improve adhesion and reduce moisture sensitivity in asphalt mixtures, two different approaches have become apparent. One approach suggests that the aggregate surface be coated by a suitable agent thatwill reverse the predominant electrical charges at the surface and thus reduce the surface energy of the aggregate. In this study, the effects of nanomaterial, namely Zycosoil, on the moisture damage of asphalt mixtures were studied.Two types of aggregates that represent a considerable range in mineralogy, limestone and granite, were evaluated during the course of this study. To assess the impact of Zycosoil on moisture damage of hot mix Asphalt, control mixes (without Zycosoil) and mixes containing Zycosoil in dry and wet conditions were tested using indirect tensile-strength (ITS) and indirect tensile fatigue (ITF) tests. The results showed that limestone has lessmoisture damage potential compared to granite. The ratio of wet/dry values of ITST and ITFT for mixes containing Zycosoil was higher than the control mix for two types of aggregate. However, in mixtures made of granite aggregate, using Zycosoil ismore effective. As the density of silanol groups ismore in its surface, these groups are hydrophilic, and Zycosoil migrates to the polar water-loving surface, reacts with the silanol groups and forms siloxane bond, the strongest bond in nature, and creates a molecular level hydrophobic zone. Crown Copyright 2012 Published by Elsevier Ltd. All rights reserved Keywords Moisture damage Zycosoil Indirect tensile-strength Fatigue Silanol group Siloxane bond. elearnica.ir-Influence_of_using_nonmaterial_to_reduce_the_moisture_susceptib.pdf

Evaluating the Effect of Zycosoil on Moisture Damage of Hot-Mix Asphalt Using the Surface Energy Method A. Khodaii1; V. Khalifeh2; M. H. Dehnad3; and Gh. H. Hamedi4 Abstract: There are several approaches for improving adhesion and moisture sensitivity in asphalt mixtures, one of which is to coat the aggregate surface with a suitable agent to change the predominant electrical charges at the surface and reduce the surface energy of the aggregate. In this study, the effects of using Zycosoil as an antistripping additive on moisture susceptibility of asphalt mixtures has been evaluated by determining the mechanism that affects the adhesive bond between the aggregate and asphalt binder using the surface free energy (SFE) method and laboratory dynamic modulus test. The percentage of the aggregate surface exposed to water (P index) has also been calculated by using the measured SFE and dynamic modulus results, and evaluated as an index for the moisture susceptibility of mixtures. The results of the SFE method show that Zycosoil decrease the difference between the free energy of the adhesion of aggregateasphalt binder in dry and wet conditions, and this difference is equal to the amount of energy released when stripping occurs. Coating of the aggregate surface with Zycosoil decreases this difference, and subsequently causes the mixture to be more resistant to moisture damage. DOI: 10.1061/(ASCE)MT.1943-5533.0000819. © 2014 American Society of Civil Engineers . Author keywords: HMA; Moisture damage; Surface free energy; Antistripping. elearnica.ir-Evaluating_the_Effect_of_Zycosoil_on_Moisture_Damage_of_Hot-Mix.pdf