Our findings show that serum γ-glutamyltransferase level could be a predictor of the development of insulin resistance in Korean men.

This study is focused on the effect of the prestress level of fiber-reinforced polymer reinforcement on the flexural and debonding behavior of strengthened beams. A total of seven reinforced concrete beams were used in the bending test. A carbon fiber reinforced polymer plate was used as the fiber-reinforced polymer reinforcement. Test variables included various prestress levels and the use of anchorage systems. The specimens were comprised of one control beam, one bonded non-prestressed carbon fiber reinforced polymer-strengthened beam, and five bonded prestressed carbon fiber reinforced polymer-strengthened beams. The deflection-controlled three-point bending test was conducted on all beams until failure. The failure of the beam with an externally bonded carbon fiber reinforced polymer plate was attributed to the debonding of the carbon fiber reinforced polymer plate. The failure mode of beams with bonded prestressed carbon fiber reinforced polymer plates was a two-stage debonding, which was followed by the rupture of the carbon fiber reinforced polymer plates; thus, the behavior of the prestressed beams changed to the unbonded state because of the anchorage system. The cracking, yield, and debonding loads of prestressed beams increased as the prestress level of the carbon fiber reinforced polymer plate increased. However, the effect on the deflection corresponding to these loads was not significant. Also, the ultimate load was constant regardless of the prestress level, except for the case of the 70% prestressed beam, but the effect on ultimate deflection was significant. The recommended appropriate prestress level in securing the ductility of a strengthened beam was 40% or less of the tensile strength of the carbon fiber reinforced polymer plate.

No abstract