4. ANTISYMMETRICAL LOADING TEST FOR COLUMNS
4.1 Specimens
Table 2 shows the properties of column specimens. Four specimens were prepared. The dimension of these all four specimens was 300mm wide and 300mm deep and the shear span ratio is 1.5. The parameters were FRP reinforcements, which were sprayed CFRP (CF-SU), sprayed GFRP (GF-SU), carbon fiber sheet (300g/m2) with one layer (CF-HU), and glass fiber sheets (444g/m2) with four layers (GF-HU). Resin of vinyl ester was utilized for all specimens. The amount of FRP reinforcements were designed so as for the FRP stiffness (elastic modulus times thickness) to be equal. Deformed rebars D13
0.5 1 1.5
(yield strength = 341MPa) and D6 (yield strength = 413MPa) were used as main bars and hoops, respectively. The designed normal weight concrete strength was 30MPa. The maximum diameter of the aggregates was 20mm. The measured compressive strength at the loading age is 34.2MPa. Table 3 shows the material properties of FRP. Regarding FRP, the material property was identical to Table 1. The properties of sheets are calculated by considering the cross-section as the designed thickness of only the fiber.
Table 2 Column specimens