Integrated Design of Structure and Material of Epoxy Asphalt Mixture Used in Steel Bridge Deck Pavement

To comprehensively investigate the integrated structural and material design of the epoxy asphalt mixture used in steel bridge deck pavement, the following works have been conducted: 1. The strain level of steel bridge deck pavement was calculated; 2. The ultimate strain level of fatigue endurance for epoxy asphalt concrete was measured; 3. The effect of water tightness of epoxy asphalt mixture on the bonding performance of steel plate interface was tested. 4. For better performance evaluation, quantitative analysis of the anti-skid performance of epoxy asphalt mixture was carried out by testing the structure depth using a laser texture tester. Results show the following findings: 1. The fatigue endurance limit strain level of epoxy asphalt mixture (600 με) was higher than that of the steel bridge deck pavement (<300 με), indicating that the use of epoxy asphalt concrete has better flexibility and can achieve a longer service life in theory; 2. The epoxy asphalt concrete has significant water tightness to protect the steel plate interface from corrosion and ensure good bonding performance; 3. The porosity of epoxy asphalt mixture used in steel bridge deck paving should be controlled within 3%; 4. In terms of anti-skid performance of bridge deck pavement, the FAC-10 graded epoxy asphalt mixture is recommended when compared with EA-10C.

Development and Laboratory Evaluation of a Cold Mix High-Early-Strength Epoxy Asphalt Concrete for Steel Bridge Deck Pavements

Epoxy asphalt concrete (EAC) is a widely used steel bridge deck pavement (SBDP) material. Due to the curing reaction, the EAC-based material needs a long curing period before opening to traffic, which in an inconvenience in the construction of SBDP. This study developed a cold mix high-early-strength (CHES) epoxy asphalt through the design of a compatilizer and curing agent system. The optimum formula of CHES epoxy asphalt was determined through a series of laboratory tests. By comparison of the performances of CHES EAC and some conventional EACs for SBDP, it was found that the developed CHES epoxy asphalt can significantly reduce the curing period, and the pavement performance of CHES EAC is, overall, excellent for application in SBDP. In addition, the sufficient allowable construction duration shows that the CHES EAC has a good construction workability.

INCREASING THE PROPERTIES OF ASPHALT CONCRETES BY USING THE EPOXID FORMATION

One of the main reasons of low durability of asphalt concrete are the properties of bitumen which is the most sensitive of all its components to the action of external factors. As thermoplastic material, bitumen becomes soft at high summer temperatures leading to rutting, shear and sags formation. At low winter time temperatures it becomes fragile and rigid that due to low-temperature compression of asphalt pavement causes the occurrence of transverse cracks. The most effective direction for increasing the durability and roughness of asphalt pavement is changing the bitumen behavior by various types of additives modification. Among the issues related to all known modifiers, the least studied is the issue of using thermosetting polymers, namely, epoxy components. The main problem with the use of epoxy resins for modification is that under the influence of high process temperatures a rapid hardening of the epoxy resin after combining with the hardener occurs. Such behavior of epoxy components limits the temperature modes and the duration of process operations for the production, transportation and placement of epoxy asphalt mixtures. In this paper, the results of the study of epoxy-asphalt concrete obtained using the cut-back bitumen are presented. The dilution of bitumen allows reducing the process temperatures of the production of epoxy asphalt concrete mixtures which increases the time for their transportation and compaction. As a result of hardening of the epoxy resin, over time, a significant increase in the strength of the epoxy asphalt concrete occurs at all temperatures. The rate of hardening of epoxy asphalt depends on the temperature of the environment. As the temperature rises, the reaction rate between the epoxy resin and the hardener increases, which is reflected in the growth of the strength of the epoxy asphalt concrete at all test temperatures, the more intense evaporation of the solvent and, consequently, the growth of water saturation and the decrease in average density. Keywords. epoxy binder, epoxy asphalt concrete, epoxy resin, modification, cut-back bitumen.