Research On Anti-cracking Of Asphalt Mixture At Low Temperature

Asphalt surface crack is the common focus in the road,the cracks of pavement not only destroy the continuity of the pavement,integrity and aesthetics,and will continuously into the moisture from the crack to soften even at the grass-roots level roadbed and pavement bearing capacity drops,produce pumping mud,steps,crack,accelerated pavement damage,endanger the road of life and quality.In addition,the influence of the temperature cracks on the paving layer in the future also nots allow to ignore,otherwise the disease will continue until the rebuild,cause huge economic losses.Therefore,improve the crack resistance of pavement asphalt roadbed is the important topic.This paper mainly studied the following four aspects of content:1.The low temperature cracking failure mechanism,mainly including the type of fracture,the causes of cracking in low temperature.2.The factors affecting cracking of asphalt pavement,this paper mainly considers the asphalt penetration,ductility at low temperature,the composition of the mixture(grading and oil-stone ratio),the influence of the dosage of admixture and outside three aspects;3.The analysis of asphalt performance evaluation method of low temperature and enumerate the current widely used on low temperature performance of asphalt mixture of test method and test index,and then combined with their own situation,selected in this paper,the most suitable test methods and test index content;4.Preparation of elastomer modified asphalt and SBS modified asphalt and through 100g,25°c,5s penetration test,under the condition of global softening point test,low temperature ductility test to compare the performance of two kinds of bitumen;In the analysis of the current several kinds of gradation design method on the basis of the advantages and disadvantages,and then combined with their own conditions,through the aggregate screening test,determined primarily by the fuller grading method in this paper,the test mixture ratio;Based on aggregate density test and Marshall test identified in this paper,the optimum proportion and finally,the paper test mixture;Through the trabecular low-temperature bending damage experiment test of low temperature performance of asphalt mixture,and the analysis of the influence of different factors on the low temperature performance differences.