参数梁的正截面受弯承载力计算混凝土强度设计值（/）C15C20C25C30C35C40C45C50C55C60C65C70C75C80fc7.29.611.914.316.719.121.123.125.327.529.731.833.835.90.911.101.271.431.571.711.801.891.962.042.092.142.182.22单位：MPa、N/mm2a 11.00.990.980.970.960.950.94受压混凝土的简化应力图形系数a 1和?普通热轧钢筋强度抗拉设计值（yy）单位：MPa、N/mm2种类HPB300HRB/HRBF335HPB/HRBF/RRB400HPB/HRBF500270300360435ba s,maxC500.4100.3990.3840.366C600.4020.3900.3750.357C700.3930.3810.3650.347C800.3840.3720.3560.337? bC500.5760.5500.5180.482C600.5560.5310.4990.464C700.5370.5120.4810.447C800.5180.4930.4630.337s,max 和