Study On Road Performance Of Asphalt Mortar Modified With Cotton Stalk Fiber

Asphalt mixtures’ road performance, such as high-temperature stability, low-temperature crack resistance and anti-fatigue properties which are good or bad, determine the service life of asphalt pavement, but the cohesive effect of asphalt mortar performance on the asphalt largely determines the asphalt road performance, especially having a major impact on the mix cracking resistance, fatigue resistance at low temperature. After mixing the fibers, the level of asphalt cement road performance can be greatly improved. Based on the existing research on the performance of asphalt mortar, this paper adds a certain amount of self-made cotton straw fiber to improve the high temperature stability and low temperature cracking of asphalt.We use cotton straw fiber, lignin fiber to prepare different type of fibers and different content of asphalt mortar, The paper evaluates temperature sensitivity of fiber with cone penetration and the performance of shear resistance, analyzing the effect of temperature, fiber type, and content of fiber on penetration depth and shear strength of asphalt; evaluates fiber asphalt mortar rheology by Dynamic Shear Rheological trials, making analysis of the influence of temperature, fiber type and content on the complex shear modulus, phase angle of asphalt. By Brookfield Viscosity test, evaluates viscosity-temperature characteristics of asphalt mortar modified with fiber, analyzing the influence of temperature fiber type and content on the viscosity of asphalt; Using Bending Beam Rheometer trials to evaluate the deformation properties of fiber asphalt cement at low temperature, making analysis of the influence of fiber type and content on hypothermia stiffness modulus, creep rate. The results show that: either cotton straw fiber or lignin fiber, fiber content have a significant effect on asphalt mortar performance, both of which have a similar effect on the performance of asphalt mortar. As the fiber content increases, asphalt mortar’s high-temperature shear performance improvements, fiber content ranging from 1% to 3%, the high-temperature performance of the asphalt mortar improvement effect is very significant; as the fiber content increases, the stiffness modulus of asphalt mortar increases, the creep rate decreases, the suitable fiber content for low-temperature performance improvement of asphalt mortar is 2%. With viscosity-temperature characteristics and construction technology asphalt mortar modified with fiber, recommend amount of cotton straw fiber content is about 2%, to provide important reference for asphalt mixture modified with fiber ratio design.