Rheological Properties Of Asphalt Emulsion

For many years,emulsified asphalt has been used as the main material for upgrading and maintenance of the asphalt highway,and its rheological properties have a very important role in the practical application of emulsified asphalt,such as viscosity and dynamic modulus.Therefore,in the production and storage,the performance should be controlled to avoid unpredictable changes in its rheological properties during production and storage.In addition,during transportation actually,the emulsified asphalt will be sheared due to internal-shearing stress caused by oscillation,presenting a very complex rheological behavior,which in turn affects other actual performance.The study of rheological properties can provide a theoretical basis for solving the problem arising from the production,storage and transportation of emulsified asphalt.Therefore,researchers at home and abroad have been paying close attention to the rheological properties of emulsified asphalt.However,the existing test method for dynamic shear rheological properties of emulsified asphalt has the problem of large test variability,which increases the amount of the test and reduces the accuracy of the test data to a certain extent.Although some studies currently exist,emulsified asphalt is treated before the test to reduce the test variability,there is still a lack of systematic research in this aspect.The article will proceed from the original dynamic shear rheology test method of emulsified asphalt,improve the original test method by analyzing the microscopic characteristics of emulsified asphalt,reduce the variability of the test results,and establish a set dynamics rheological test method which is suitable for emulsified asphalt materials,and study the rheological characteristics of emulsified asphalt based on this method,which is combined with the test of emulsified asphalt micro-characteristics,establish the relationship between the emulsified asphalt macro-dynamic rheological characteristics and micro-characteristics,which provides new ideas for the research of rheological properties of emulsified asphalt products.In view of this,starting from the variability of the parallel test,the necessity of pre-shear in the dynamic rheological test of emulsified asphalt is verified.And the controlled elements and processing steps before the emulsified asphalt test are discussed.The research on emulsion rheology of materials science shows that for the treatment of emulsion samples before the test,the researchers mainly control the treatment degree from the loading size and loading-action time.Regardless of equipment factors,in the pretreatment process of emulsified asphalt test,design tests to study the control method of loading size,loading-action time and other conditions.And use parallel tests to verify its rationality and reliability,laying the foundation for the research on the rheological properties of emulsified asphalt..Based on the improved rheological testing method of emulsified asphalt,the rheological properties of emulsified asphalt under dynamic load are tested.And the dynamic rheological parameters of emulsified asphalt such as storage modulus and loss modulus in frequency domain and time domain are analyzed under different loading conditions.And establish a dynamic rheological model to link the macroscopic dynamic rheology of emulsified asphalt with microscopic characteristics.At the same time,combined emulsified asphalt microscopic droplet size with size distribution,interfacial tension to analyze the relationship between emulsified asphalt macroscopic and microscopic.Finally,based on the dynamic rheological model and microscopic characteristic parameters,the dynamic modulus of emulsified asphalt is predicted to verify the applicability of the dynamic rheological model.The study describes the improvement process of the rheological testing method of emulsified asphalt,which lays the foundation for the research of the dynamic rheological properties of emulsified asphalt.At the same time,combined with the micro-feature test,the relationship between the macro dynamic modulus of the emulsified asphalt and the micro-feature interfacial tension and the droplet size and size distribution is established,which provides a certain reference and basis for the research on the rheology of emulsified asphalt emulsion materials.