Improvement on the Crack Resistance Property of Semi-Flexible Pavement by Cement-Emulsified Asphalt Mortar

Abstract

Semi-flexible pavement (SFP) has some excellent characteristic such as high carrying capacity, good wearing resistance, water stability and durability. However, the SFP appears low temperature crack and fatigue cracking seriously because there are large differences in the interfacial bonding property and the elastic modules between its two major parts: Lag gap asphalt mixture (LGAM) and cement mortar. All of these are caused by the large stiffness of cement mortar. In order to improve the crack resistance property of SFP, six kinds of cement-emulsified asphalt mortars (CEAM) were developed to enhance the adhesive property and reduce the elastic modules. The cement-emulsified asphalt mortar semi-flexible pavement material (CEAMSFP) was obtained by using this kind of CEAM. In the CEAM and the CEAMSFP, six emulsified asphalt-to-cement (A/C) ratios were considered in the study: 0, 0.1, 0.2, 0.3, 0.4 and 0.5 by weight of emulsified asphalt. The results indicated that the increasing of the A/C ratio improved the bonding interface and the flexible of the CEAM. The increasing of the A/C ratio improved the low temperature resistance and fatigue life of the CEAMSFP. It was also shown that the A/C ratio of 0.3 was found to be the optimum ratio that achieved a balance in performance and the value of the pavement. In this condition, the adhesion level between LGAM and cement grout reached 5，the elastic modules of mortar decreased by 62.5% and the fatigue life of SFP increased by 43.6%.

Performance Characterization of Semi-Flexible Composite Mixture

“…Studies by Hao and Ling [12,13] indicated that semi-flexible pavement have good low temperature cracking resistance and excellent rutting resistance. Huang et al [14] used six emulsified asphalt-to-cement (A/C) ratios and found 0.3 was the optimum one that can balance performance of SFCM between elastic modulus and fatigue life [14]. Al-Qadi et al [2,6] studied SFCM as a possible alternative for bridge deck overlays considering its improved engineering performance compared to a typical AC wearing surface.…”

“…The skid resistance of SFCM was noted as a problem shortly after paving but it was improved within a few months, and kept at a good level by the end of the fourth year. The pavement condition rating (PCR) value of SFCM, which is a parameter to quantify pavement's overall performance based on measurements of roughness, surface distress, skid resistance and deflection, were acceptable by the end of the survey [14].…”

Study on Mechanics‐Based Cracking Resistance of Semiflexible Pavement Materials

“…Wang and Wu [8] evaluated the cracking resistance of semiflexible pavement materials based on the fracture toughness using the J-integral theory and three-point bending semicircular beam test. Huang et al [9] studied the cracking resistance of semiflexible pavement materials based on cement-emulsified asphalt mortar. At present, studies of the anticracking of semiflexible pavement have been mainly focused on controlling the volumetric stability of the cement mortar and the overall cracking resistance of semiflexible pavement materials.…”

Engineered Semi-Flexible Composite Mixture Design and Its Implementation Method at Railroad Bridge Approach

“…(1) SFCM is the combination of the open-graded asphalt mixture (as the core structure) and cement mortar (as the filler). It combines the flexibility and durability of the asphalt concrete and the stiffness of the cement concrete (9,18).…”

“…They focus on either modifying the track component or making changes to the entire structure. Amplifying the size and/or increasing the space between the ties is a simple method of modifying the track component, which could reduce the vertical displacement by distributing the loads to a broader area ( 8 , 9 ). Rubber pads are often used in the railway to reduce vibration and improve the damping of the structure ( 10 ).…”