Comprehensive performance study of materials after innovative utilizing epoxy resin curing of loess and river sand: Mechanical properties, durability and microstructure.

In order to enhance the application of epoxy mortar in pavement repair engineering, an epoxy-based repair material with short molding time, easy fabrication, high early strength and good durability was developed. In the past, the fillers of epoxy mortar were mainly fly ash and silica fume. In this paper used loess (LS) and river sand (RS) which were lower cost and more readily available, mixed with epoxy resin to make a new epoxy mortar system. The influence of epoxy resin mass fraction (20%,25%,30%), filler type (LS, RS), and LS-to-RS ratio (2:1,1:1,1:2) on the mechanical properties and durability of the epoxy mortar were investigated. It was observed that the early compressive strength of the specimens increased significantly with the increase of the proportion of epoxy resin in the mixture, reaching 49.2 MPa after 2 h of curing. Moreover, when the mass fraction of epoxy resin increased from 20% to 30%, the flexural strength increased by more than 20% after curing for 2 h. Additionally, compared to single filler, mortar containing both LS and RS exhibited superior durability. Unlike the specimens of the all-river sand group L0, which showed a 40% to 60% decrease in mechanical properties in sulfate and chloride saline solutions, almost no loss of strength occurred in the L1R1 group. This phenomenon can be explained by the findings from SEM and MIP tests that the L1R1 group has a more compact pore structure compared to the L0 group. [Display omitted] • Epoxy resin with loess and river sand to form a new pavement emergency repair material system. • Under the curing effect of epoxy resin, the compressive strength of epoxy mortar can reach 49.2 MPa for 2 h. • Epoxy mortar had excellent durability in water and saline solutions. [ABSTRACT FROM AUTHOR]