Tian-Feng Yuan 교수

Abstract This study presents the shear capacity of eco-friendly high-strength concrete (HSC) beams reinforced by 0.75% (by volume) of hooked steel fibers or shear stirrups with various spacings. Five large-scale HSC beams with steel fibers or stirrups were tested and investigated with respect to shear capacity, failure mode, and crack patterns. The test results indicate that all five tested beams finally failed by a shear-critical failure mode and that the use of 0.75 vol% of steel fibers signif

Carbon-fiber-reinforced-polymer (CFRP) bar with high tensile strength is expecting when used with ultra-high-strength-concrete (UHPC), but the reduction of mechanical properties of CFRP under thermal effects is an important issue. This study invesitigated the residual bond strength of CFRP bars in UHPC specimens after exposure to elevated temperatures. For comparison, the residual bond strength of steel rebar was also conducted after exposure to elevated temperatures. For this purpose, the pull-

This paper presents experimental investigations on the mechanical properties of no-slump high-strength concrete (NSHSC), such as the compressive and flexural strength. First, to determine the proper NSHSC mixtures, the compressive and flexural strength of three different water-to-binder ratios (w/b) of specimens with and without polyethylene (PE) fiber was tested at test ages. Then, the effect of hybrid combinations of PE fiber and steel fiber (SF) on the compressive strength, flexural strength,

This study investigates the flexural behavior of normal-strength concrete (NSC) beams that were strengthened with no-slump, high-strength, high-ductility concrete (NSHSDC). A set of slant shear tests was performed to investigate the initial performance of the NSC substrate strengthened with NSHSDC. Slant shear tests considered two types of roughness of interface and five angles of the interface between NSC and NSHSDC. The test results showed that except for specimens with a 75° interface angle,

There is increased interest in applying electromagnetic (EM) shielding to prevent EM interference, which destroys electronic circuits. The EM shielding's performance is closely related to the electrical conductivity and can be improved by incorporating conductive materials. The weight of a structure can be reduced by incorporating lightweight aggregates and replacing the steel rebars with CFRP rebars. In this study, the effects of lightweight coarse aggregate and CFRP rebars on the mechanical an

High-performance concrete (HPC) is widely used in construction according to great mechanical properties, but it has a high risk of shrinkage cracking due to autogenous shrinkage stress. Therefore, the aim of this research was to investigate the effect of a combination of expansive admixture (EA) and shrinkage reducing admixture (SA) on the autogenous shrinkage of high-performance concrete without heat treatment. Two different EA to cement weight ratios of 0.0, 5.0%, and two different SA to cemen

The application of electric arc furnace oxidizing slag (EAS) in high strength concrete (HSC) as the cementitious material is investigated in this study. The microstructure and mechanical properties of HSC with four different replacement ratios of EAS were evaluated and HSC with two replacement ratios of ground granulated blast furnace slag (GBS) was used for performance comparison. The results show that the HSC with EAS replacement ratios smaller than 15% undergo similar hydration processes and

It is important to consider establishing a shelter in place (SIP) using existing facilities to prepare for unpredictable and no-notice disasters. In this study, we evaluate the building-information-modeling (BIM)-based approach to simulate the strategic location of SIP and its strengthening method. BIM software was used to model a light rail station and analyze the elements of the facility that can affect the evacuation time to reach the SIP. The purpose of this study was to understand the effec

This study analyzes the pore structure and durability of concrete according to four different ratios of steelmaking slag powder (SSP). Concrete containing SSP increased the formation of gel and capillary pores due to delayed hydration, and the largest cumulative pore volume was observed when the incorporation ratio was 20%. In terms of durability, the incorporation of SSP had decreased performance compared to concrete without SSP (NN), which was due to changes in the pore structure caused by inc

Among public facilities, facilities belonging to Multi-Group (I) include high-rise buildings, tunnels, and subway stations, and the location of Shelter in Place (SIP) is an important factor in the safety of citizens. However, subway evacuation maps usually induce evacuation to ground level or the tunnel of a subway platform without considering the location of SIP. In other words, since the location of the SIP is not determined, conditions, such as ventilation, air conditioning facilities, and st