Research On The Performane Of Asphalt Pavement Crack Sealant Based On Failure Characteristics

In recent years, there are a variety of road diseases during the large-scaleconstruction of asphalt pavement. Pavement crack is one of the major diseases.Water, air and other things can enter into road through pavement crack, whichwould lead to more rapid pavement deterioration. Crack sealing using crack sealantis an economic and effective preventive maintenance activity to preventdeterioration and extend service life. However, current crack sealant specificationscan’t base on the field performance. This test researches the performance of cracksealants and the indexes are proposed based on the failure characteristics.The width changing with temperature is one of the major causes of sealingfailure. The widths of5cracks are measured in one year. It is found that theabsolute change value is biggest in winter. Change of crack width is also measuredin one summer day and one winter day respectively. It shows that the change valuein winter is higher than that in summer, but much lower than that in one year. Basedon the laws of cracks in one year, the reasonable crack sealing time is determined.In order to research itself working performance of sealant, a series ofexperiments are conducted including installation property, low temperatureperformance and high temperature performance. Using the Brookfield rotationalviscometer, the field installation property of sealant is analyzed. About the propertyof sealant at low temperature, bending creep test is conducted. Combining theprinciple of time-temperature superposition, the creep rate, creep compliance mastercurve and relaxation modulus master curve are analyzed. As the high temperaturebehavior, the flow test and dynamic shear test are used. The flow test can contrastflowing property of different sealants in high temperature. The dynamic shear testcan analyze the complex shear modulus master curve, phase angle and rut factor atdifferent temperature and shear frequency.The interfacial strength and anti-shearing property of the system composed bysealant and crack walls are researched. The study about interfacial strength includesadhesion strength and integral strength. Based on the principle of surface energy,the work of adhesion is measured to evaluate the adhesion strength between sealantand crack walls. Besides, the integral strength between sealant and crack walls ismeasured by using pull-out test. In order to analyze the property of resisting shearforce caused by traffic load, the direct shear test is conducted. By direct shear test indifferent temperature, the maximum shear destruction force and destruction work are measured. The two indexes can be used to evaluate the anti-shear ability of thesystem composed by sealant and crack walls.By experiment research, it indicates that these methods can analyze the filedperformance of sealant. What’s more, one kind of sealant doesn’t have goodperformances in all respects. All aspects of performances should be considered andone aspect property should be considered particularly when selecting sealant.