|Budget Amount *help
¥5,000,000 (Direct Cost : ¥5,000,000)
Fiscal Year 1991 : ¥300,000 (Direct Cost : ¥300,000)
Fiscal Year 1990 : ¥2,500,000 (Direct Cost : ¥2,500,000)
Fiscal Year 1989 : ¥2,200,000 (Direct Cost : ¥2,200,000)
Objective of this study is emphasized on bond performance between continuous FRP rods, which are substitute reinforcement for steel bars, and concrete. Used materials were high-strength light-weight concrete of specified compressive strength of 360kgf/cm^2 and carbon, aramid and glass continuous fiber rods. To make a comparison with ordinary RC, normal concrete and steel bars for longitudinal reinforcement were also used.
Total of cantilever type specimens was 43, i. e., 29 of light-weight concrete and 14 of normal one. Their size was 20cm wide and 35cm deep. Bond splitting test was carried out by pulling independently out their top and bottom longitudinal reinforcement of diameter of about 13mm with bonding length of 30cm. Test results were referred to those derived from test of 6 beam type specimens, which failed in bond splitting, under cyclic and antisymmetric loading.
Empirical formulae, in which bond splitting strength was expresed as the sum of those due to concrete and lateral reinforcement, were established by recurrent analysis, by which relationships of top to bottom reinforcement were also determined. Other leading results were as follows. Strengths due to concrete had hardly relation to its kind. In case of steel longitudinal reinforcement strengths due to fiber lateral reinforcement could be evaluated by multiplying values of steel case by ratios of Young's modulus of it to steel to the third power. In case of fiber reinforcement only, strengths due to concrete varied with shape and stiffness of longitudinal reinforcement and generally speaking, the lower stiffness was, the lower strength was. As to effect of lateral reinforcement ratios of contribution of corner longitudinal bars to middle ones were about 2 : 1.6, while they were 2 : 1 in case of steel longnal bars. Ultimate strength of beam specimens could be predicted from analysis of results of cantilever test.