Research on the Fatigue Behavior of Cement Asphalt Mortar Exposed to Water

Abstract

Water erosion is one of the major factors for performance degradation of cement asphalt mortar (abbreviated to CA mortar, or CAM). In this paper, the influence of gap depth, coupling effect of water and pressure on the fatigue behavior of CA mortar was investigated. Results indicated that the damage of bonding surface became more seriously with the increase of gap depth, and when the gap depth was 19 to 38% of the structure size, the destruction exacerbated. Results also indicated that CA mortar was damaged more seriously under the coupling effect of water and pressure; the destruction first occurred on the surface between slab track and CA mortar rather than that between concrete roadbed and CA mortar. Timely repair with epoxy resin prevented the further water erosion well, and improved the service life of CA mortar.

Fatigue resistance investigation of warm‐mix recycled asphalt binder, mastic, and fine aggregate matrix

“…The binder ageing procedure is briefly introduced as follows. More details can be found elsewhere The virgin binder is aged 85 minutes at the temperature of 163°C using the rolling thin film oven test (RTFOT) to simulate the short‐term ageing which occurs during the production and construction of new asphalt mixtures. The residue after RTFOT is aged at the air pressure of 2.1 MPa and the temperature of 100°C using the pressure ageing vessel (PAV) to simulate the long‐term ageing which occurs during the service period of new asphalt mixtures.…”

“…To determine the FAM weight composition, the AC‐13 mixture typically used as the surface layer of asphalt pavements in China was selected. The FAM gradation was refigured based on 100% passing a certain 4.75‐mm sieve . The optimum binder content of 8.2% was determined by the specific surface area method, in which it was assumed that each aggregate particle was homogeneously coated by the asphalt film with the thickness of 8 μm…”

Predicting fracture behavior (mixed‐modes I/III) of cement asphalt mortar under fatigue and static loading conditions using response surface method

“…Fatigue damage has profound impacts on the loadcarrying capacity and useful living of cement emulsified asphalt mortar (CEAM), which is among the essential elements of ballastless train tracks. The CEAM's fatigue life is known to be impacted by a variety of factors embracing the mixture's components and bitumento-cement ratio, 1,2 voidage, 3,4 age hardening, exposure to water, 5,6 experimental settings like stress magnitude and loading rate, 7 and temperature. 2,6,8 In a study by Shan et al, scanning electron microscope and mercury intrusion porosimetry analyses exhibited that applying the fatigue cycles to CEAM specimens changed the type of voids (micro and macro size), decreasing macro voids' total volume and increasing the volume of micro voids as loading cycles progressed.…”

“…Fatigue damage has profound impacts on the load‐carrying capacity and useful living of cement emulsified asphalt mortar (CEAM), which is among the essential elements of ballastless train tracks. The CEAM's fatigue life is known to be impacted by a variety of factors embracing the mixture's components and bitumen‐to‐cement ratio, 1,2 voidage, 3,4 age hardening, exposure to water, 5,6 experimental settings like stress magnitude and loading rate, 7 and temperature 2,6,8 …”

A Novel Method for Improving Segregation Resistance of Cement Asphalt Mortar

“…Damping ratio of CA was increased by admixing rubber powder, which can be better for energy absorption and vibration attenuation [8]. A model to determine the mechanical properties of CA mortar in the field was proposed [9].The destruction of CA mortar first occurred on the surface between slab track and CA mortar rather than that between concrete roadbed and CA mortar [10]. There are few publications focusing on its rheological behavior.…”