Strength Development,Toughness and Fire Resistive Performance of 150 to 200N/mm2 Super-High Strength,High Performance Concrete
Kenro MITSUI, Toshio YONEZAWA, Masaro KOJIMA, Mitsuo KINOSHITA and Hirozo MIHASHI
Abstract:Super high strength concrete with compressive strength of 150 to 200N/mm2 using hybrid fiber reinforcement of organic and steel fiber was developed. Properties of fluidity of fresh concrete and effect of curing condition on strength development were studied. Viscosity of fresh concrete was significantly reduced by newly developed Maleate polycarboxylate-based superplasticizer. Strength development of high strength concrete was enhanced by high temperature steam curing. Hybrid fiber reinforcement was effective to improve toughness and fire resistance of super high strength concrete. The higher the aspect ratio and tensile strength of steel fiber, the higher the toughness of concrete became. Hybrid fiber reinforcement enables to reduce spalling and to maintain fire resistance for 3 hours in super high strength concrete columns. Key Words:High strength concrete, Hybrid fiber reinforcement, Fluidity, Strength development, Toughness, Fire resistance