| In this paper,the semi-circular bending test(SCB)is used to study the low temperature characteristics of asphalt mortar.The factors affecting the low temperature characteristics of mortar are tested indoors and analyzed on the data.The influence of various influencing factors on the low temperature performance of asphalt mortar is analyzed.Qualitative and quantitative analysis of low temperature characteristics provides a basis for improving the performance of asphalt mortar in low temperature environment.This paper firstly collects and summarizes the research status and results of low temperature performance research,semi-circular bending test,mineral powder and other effects on mortar of asphalt mortar and glue at home and abroad,and puts forward the main research contents of this paper.Specific research routes.Secondly,in order to determine the specific operation of the semi-circular bending crack test,the bending strength is used as the index for evaluating the low temperature crack resistance of the mortar in the semi-circular bending test.The thickness of different test pieces,different slit depths,different loading rates,different test temperatures The influence of the results of the semicircular bending test was studied,and the DIC digital image correlation technique was used as an auxiliary means to analyze and eliminate the fracture energy error caused by the creep of the loading part in the semicircular bending test;a suitable semicircular bending test method was determined.Then,the effects of asphalt type and mineral powder type on the low temperature performance of mortar were studied.The asphalt film thickness of different grades of asphalt mixture was analyzed and analyzed.The appropriate asphalt film thickness and mineral powder content were obtained,and three kinds of asphalt film thickness were prepared.Four kinds of asphalt mortar samples with different mineral powder contents were analyzed.The effects of asphalt film thickness and ore powder content on the low temperature crack resistance of mortar specimens were analyzed from the strength and energy.Finally,for the 12 kinds of mortar mixture with different asphalt film thickness and different mineral powder content,the aging process was carried out for 4h and 12 h respectively by oven aging method to simulate the oxidation process of the mortar in the actual project mixing and transportation process,and the aging process will be carried out.The mixture is compacted and cut into semi-circular specimens.Based on the semi-circular bending test,the influence of aging time on the strength and energy of asphalt mortar with different asphalt film thickness and mineral powder content is studied,and the mortar content and the peak load of mortar before and after aging are studied.Correlation analysis of the displacement and fracture energy at the location shows that the content of the cement is well correlated with the peak displacement and fracture energy of the mortar,which can be used to analyze and guide the improvement of the low temperature of the mortar.Based on the semi-circular bending test,this paper analyzes the test factors such as test temperature,loading rate,asphalt type,mineral powder type and content,asphalt film thickness and other material factors,and the effect of aging on mortar performance,which is of great significance for analyzing and improving mortar performance. |
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