Browsing by Author "Mutsuyoshi, H"

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Open Access
Development of GFRP and UHF composite girders
(The Thirteenth East Asia-Pacific Conference on Structural Engineering and Construction (EASEC-13), 2013-09-13) Wijayawardane, I. S. K; Mutsuyoshi, H; Perera, S. V. T; KANAYA, Y
In this paper, the development of a composite girder using glass fiber reinforced polymer (GFRP), ultra high strength fiber reinforced concrete (UHF) and fiber reinforced polymer (FRP) bolts is illustrated. Experiments were carried out previously with steel bolts which connect the UHF blocks to the GFRP beam. Because of the corrosion of the steel bolts, the life span of the composite girder is reduced. Therefore, in this test series FRP bolts were used. Four point bending tests were conducted for a number of I-beams of same cross-sectional dimensions having epoxy bonded and FRP bolted UHF blocks at the top flange. In order to check the performance of the FRP bolt connections between FRP beam and UHF blocks, different bolt diameters and bolt spacing were considered. Behavior of the strain variation of top flange was compared in order to check the utilization of the ultimate tensile strain of GFRP. In fact, the experiment results show that the failure load of the composite I-beam has reduced compared to similar steel bolt connection. However, failure load similar to steel bolt connection can be achieved with many FRP bolts. Therefore, the FRP bolts can be used in UHF and GFRP composite girder which increase the durability of the girder.
Embargo
Shear Behavior of Reinforced High-Strength Concrete Beams
(Institute publication policies, 2013-01-01) Perera, S. V. T; Mutsuyoshi, H
This paper describes the shear behavior of reinforced high-strength concrete (RHSC) beams (fc′ > 100 MPa [14,500 psi]) without web reinforcement. The use of high-strength concrete (HSC) has led to some concerns about its shear strength because of its brittleness, smooth fracture surface, and high early-age shrinkage. Test results indicated that the ratio of uniaxial compressive strength to tensile strength (the ductility number) of the concrete relative to that of the aggregate governs the shear strength of HSC. When the ductility number of the concrete coincided with that of the aggregate, the shear strength remained constant, irrespective of concrete strength. When the ductility number of the concrete was higher than that of the aggregate, however, shear strength started to decrease due to the smooth fracture surface and brittleness. By introducing earlyage shrinkage and a suitable aggregate size, the modified compression field theory (MCFT) was found to accurately predict the shear strength of RHSC beams.
Embargo
Shear Behavior of Reinforced High-Strength Concrete Beams
(American Concrete Institute, 2013-01-01) Perera, S. V. T; Mutsuyoshi, H
This paper describes the shear behavior of reinforced high-strength concrete (RHSC) beams (fc′ > 100 MPa [14,500 psi]) without web reinforcement. The use of high-strength concrete (HSC) has led to some concerns about its shear strength because of its brittleness, smooth fracture surface, and high early-age shrinkage. Test results indicated that the ratio of uniaxial compressive strength to tensile strength (the ductility number) of the concrete relative to that of the aggregate governs the shear strength of HSC. When the ductility number of the concrete coincided with that of the aggregate, the shear strength remained constant, irrespective of concrete strength. When the ductility number of the concrete was higher than that of the aggregate, however, shear strength started to decrease due to the smooth fracture surface and brittleness. By introducing earlyage shrinkage and a suitable aggregate size, the modified compression field theory (MCFT) was found to accurately predict the shear strength of RHSC beams
Open Access
Shear Capacity of Reinforced High-Strength Concrete Beams without Web Reinforcement
(The Thirteenth East Asia-Pacific Conference on Structural Engineering and Construction (EASEC-13), 2013-09-11) Perera, S. V. T; Mutsuyoshi, H
Three series of reinforced concrete (RC) beams without web reinforcement were tested to determine their diagonal cracking shear strengths and ultimate shear capacities. Within each series, the shear span to depth ratio was held constant at 3.0, 3.5, or 4.0 while the characteristic compressive strength of concrete was varied from 36 to 194 MPa in otherwise identical specimens. Test results indicated that the ratio of uniaxial compressive strength to tensile strength of the concrete was proportional to concrete brittleness. According to the JSCE code and the ACI code, the shear strength of RC beams increases with increasing concrete strength. However, test results showed that, the JSCE code and the ACI code for predicting shear strength were not safe.