The discrete element method (DEM) was used to establish the slump model and J-Ring model of concrete to describe the flow behavior in the slump test and J-Ring test. Then, the contact parameters of particle-particle and particle-geometry for the concrete DEM model, including restitution coefficient, rolling friction coefficient, static friction coefficient, and surface energy, were measured. In order to avoid the influence of the shape and size of the aggregate, this paper used high-precision glass spheres as the aggregate of the concrete for meso-calibration test, slump test, and J-Ring test. Comparing the simulation results of DEM model with slump test result, a very high agreement between the initial stage, the rapid flow stage, and the slow flow stage of the slump flow–time curve can be found as well as the final slump and slump flow. Moreover, similar to the slump DEM model, the DEM models of J-Ring test, V-funnel test, and U-channel test were established to study the passing ability and filling ability of concrete with outstanding accuracy. Therefore, the concrete DEM model with contact parameters and JKR model can be adopted to study the flow behavior of the fresh concrete.

Engineered Cementitious Composite (ECC) is an advanced composite material with strain-hardening and multiple-cracking behaviors. In this study, two types of ECC materials were troweled on masonry infill walls strengthened with expansion bolt and interfacial agent. The seismic performance of the unreinforced and the ECC reinforced masonry structures was evaluated by the reversed cyclic loading test. The results showed that the application of the ECC on the masonry infill walls can improve the ultimate bearing capacity (in plane), ductility, stiffness and accumulative energy dissipation of the structure. Compared with the masonry structure with one side reinforced by the ECC, the structure with both sides reinforced by the ECC could better improve the ultimate bearing capacity, stiffness and cumulative energy dissipation with little difference on the ductility improvement. Moreover, the expansion bolt and the interfacial agent used to improve the connection between the ECC and the masonry structure have the ability to greatly increase the mechanical properties of the structure under cyclic loading.