Research On Modification Of Asphalt Mortar By Basalt Fiber

With the rapid development of China's transportation industry,the traffic volume has increased sharply,placing higher requirements on asphalt mixtures.In recent years,more and more attention has been paid to adding modifiers to asphalt mixtures to improve their pavement performance.In practical engineering applications,basalt fiber is often used as a modifier to improve the use of asphalt mixtures.performance.In the asphalt mixture with basalt fiber,basalt fiber,asphalt and mineral powder together constitute the asphalt mortar,and its performance plays an important role in the performance of the mixture.Most of the current research only focuses on the performance of the mortar composed of basalt fiber and asphalt.It is still necessary to study the effect of basalt fiber on asphalt mortar(asphalt mortar with different powder to rubber ratio).Therefore,the paper uses the domestic conventional asphalt index test and the American Superpave asphalt index test to study the modification effect of basalt fiber on asphalt mortar.The high temperature performance,low temperature performance and fatigue performance of basalt fiber with different powder to rubber ratio asphalt mortar are developed.the study.Based on the research results and the glue theory based on the strength of the mixture,the optimal fiber content of AC-13 C asphalt mixture was given.The rationality of the optimal fiber content was verified through the mix ratio design and performance test.The research work carried out in this paper and related results are as follows:(1)Through the study of the micro-microscopic structural characteristics of basalt fiber and mineral powder,and the electron microscope scanning of basalt fiber asphalt mortar,the micro-structure model of basalt fiber modified asphalt mortar was established,and the modification mechanism of basalt fiber was discussed in combination with the composite material theory.(2)Based on the research results of the modification mechanism of basalt fiber,basalt fiber with different contents is mixed into 70 # matrix asphalt and SBS modified asphalt with different powder-to-binder ratio,and it passes the conventional three major index tests,rotational viscosity test and cone penetration test.As well as dynamic shear test and bending beam rheological test,the performance of asphalt powder with different powder-to-binder ratio in different basalt fiber content was studied.The study found that basalt fiber can enhance the high temperature performance and shear resistance of asphalt mortar with different powder-binder ratio,and the increase of powder-binder ratio has an amplification effect on the enhancement of mortar performance.Basalt fiber and mineral powder have an adverse effect on the low-temperature performance of the two asphalt mortars.As the content of basalt fiber increases,the low-temperature performance of the asphalt mortar decreases.In the different performance studies of basalt fiber with different ratio of asphalt to asphalt,the optimal dosage is also different.According to the research results,the recommended value of the optimal dosage under different conditions is given.(3)Based on the research results of basalt fiber modification of asphalt mortar,the optimal content of basalt fiber in asphalt mixture under high temperature is studied,and the best powder-to-binder ratio of asphalt mortar at high temperature and the recommended value of basalt fiber content are deduced The formula for calculating the amount of basalt fiber in the mixture is given.At the same time,the AC-13 C type was selected for mix ratio design,and compared with the currently used basalt fiber content asphalt mixture.The performance of the asphalt mixture was compared through indoor tests such as rutting and low-temperature bending,and the feasibility of the research results was initially verified.