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Compressive Strength Effects on Flexural Behavior of Steel Fiber Reinforced Concrete
Jang, Seok Joon,Jeong, Gwon Young,Lee, Mi Hwa,Rokugo, Keitetsu,Yun, Hyun Do Trans Tech Publications, Ltd. 2016 Key Engineering Materials Vol.709 No.-
<P>This paper presents results of experimental investigation to evaluation the effects of compressive strength on flexural behavior of steel fiber-reinforced concrete (SFRC). For this purpose, normal and high strength SFRCs with two different fiber volume fractions of 0.5 and 1.0% were prepared. Compressive strength, modulus of elasticity, flexural strength and toughness were measured with tests on SFRC cylinders and prisms. Test results indicated that steel fiber volume fraction significantly affects the flexural strength and toughness of SFRC. However, the high strength SFRC showed reduction in flexural toughness compared with the normal strength SFRC. It can be concluded that flexural behavior of SFRC depends on both compressive strength and fiber volume fraction.</P>
Kobayashi, Koichi,Suzuki, Masato,Dung, Le Anh,Yun, Hyun-do,Rokugo, Keitetsu Elsevier 2018 Construction and Building Materials Vol.178 No.-
<P><B>Abstract</B></P> <P>SHCC mixtures with various water cement ratios and different types of fiber (PVA and PE) were tested with an aim to clarify the properties of cracked SHCC. After examining the mechanical performances of the composites, chloride penetration and rebar corrosion tests were conducted on cracked SHCC specimens.</P> <P>PE fiber, PVA fiber, and a mixture of PE and PVA were added in SHCC. Part of the cement was replaced with limestone powder in some mixtures to vary the water cement ratio of the mortar matrix. For SHCC mixtures containing PVA fiber, which has lower strength and Young's modulus, the water cement ratio had to be increased to obtain a strain hardening property. The chloride penetration test revealed that chloride could penetrate into SHCC through fine cracks and that the width of the fine cracks had no bearing on the amount of chloride accumulated in the crack fracture surfaces. On the other hand, chloride penetration through cracks into the mortar matrix was affected by the number of cracks and water cement ratio. As a result, the corrosion area on rebar in cracked SHCC was also largely dependent on the number of cracks and water cement ratio. However, the corrosion area was smaller than that of ordinary mortar. When the strain is in a small range, the corrosion prevention performances of PE-SHCC and PVA-SHCC were more or less the same.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Rebar corrosion protection performances of cracked SHCCs were investigated. </LI> <LI> Chloride penetration through cracks into SHCC was affected by the number of cracks. </LI> <LI> It was also affected by W/C of mortar matrix. </LI> <LI> The corrosion prevention performances of PE-SHCC and PVA-SHCC were comparable. </LI> <LI> Even SHCC with low ductility can enhance the durability of RC structures. </LI> </UL> </P>
Kim, Jeong-Eun,Park, Wan-Shin,Jang, Young-Il,Kim, Sun-Woo,Kim, Sun-Woong,Nam, Yi-Hyun,Kim, Do-Gyeum,Rokugo, Keitetsu Korea Concrete Institute 2016 International Journal of Concrete Structures and M Vol.10 No.3
When the energy performance of concrete is substantially higher than that of normal type concrete, such concrete is regarded as energy efficient concrete (WBSCSD 2009). An experimental study was conducted to investigate mechanical properties of energy efficient concrete with binary, ternary and quaternary admixture at different curing ages. Slump test for workability and air content test were performed on fresh concretes. Compressive strength, splitting tensile strength were made on hardened concrete specimens. The mechanical properties of concrete were compared with predicted values by ACI 363R-84 Code, NZS 3101-95 Code, CSA A23.3-94 Code, CEB-FIP Model, EN 1991, EC 2-02, AIJ Code, JSCE Code, and KCI Code. The use of silica fume increased the compressive strengths, splitting tensile strengths, modulus of elasticities and Poisson's ratios. On the other hand, the compressive strength and splitting tensile strength decreased with increasing fly ash.
Jeong-Eun Kim,Wan-Shin Park,Young-Il Jang,Sun-Woo Kim,Sun-Woong Kim,Yi-Hyun Nam,Do-Gyeum Kim,Keitetsu Rokugo 한국콘크리트학회 2016 International Journal of Concrete Structures and M Vol.10 No.3
When the energy performance of concrete is substantially higher than that of normal type concrete, such concrete is regarded as energy efficient concrete (WBSCSD 2009). An experimental study was conducted to investigate mechanical properties of energy efficient concrete with binary, ternary and quaternary admixture at different curing ages. Slump test for workability and air content test were performed on fresh concretes. Compressive strength, splitting tensile strength were made on hardened concrete specimens. The mechanical properties of concrete were compared with predicted values by ACI 363R-84 Code, NZS 3101-95 Code, CSA A23.3-94 Code, CEB-FIP Model, EN 1991, EC 2-02, AIJ Code, JSCE Code, and KCI Code. The use of silica fume increased the compressive strengths, splitting tensile strengths, modulus of elasticities and Poisson’s ratios. On the other hand, the compressive strength and splitting tensile strength decreased with increasing fly ash.