混凝土离差系数及保证率计算方法

混凝土离差系数及保证率计算方法1、离差系数 CV 2、混凝土保证率 P:① 先计算 z 值: 上两个式中:——抽样混凝土试件平均强度(MPa);——混凝土强度设计值(MPa);σ(n-1)——混凝土统计均方差;(MPa)Cv——混凝土离差系数(%)② 以 z 值查标准正态分布表(附表 1 续)可求得混凝土保证率 P。SL176-2025同一标号混凝土 28d 强度组数 5≤i<30-0、7>R 标-1、6≥0、83R 标(R 标≥20MPa) ≥0、80R 标(R 标<20MPa)<2、0(1、5)MPa,应该=2、0MPa(R 标≥20MPa),=,1、5MPa(R 标<20MPa)同一标号混凝土 28d 强度组数 2≤i<5≥1、15R 标Rmin≥0、95R 标同一标号混凝土 28d 强度组数 i=1R≥1、15R 标CV<0、14,0、18(R 标≥20MPa)CV<0、18,0、22(R 标<20MPa)离差系数 Cv==0、053;;概率度系数 t==1、935,再经查询正态分布表得出保证率为 97、3。无筋混凝土保证率 P85%优良,80%合格配筋混凝土保证率 P95%优良,90%合格z01234567890.00.10.20.30.40.50.60.70.80.91.01.11.21.31.41.51.61.71.81.92.02.12.22.32.42.52.62.72.82.90.50000.53980.57930.61790.65540.69150.72570.75800.78810.81590.84130.86430.88490.90320.91920.93320.94520.95540.96410.97130.97720.98210.98610.98930.99180.99380.99530.99650.99740.99810.50400.54380.58320.62170.65910.69500.72910.76110.79100.81860.84380.86650.88690.90490.92070.93450.94630.95640.96480.97190.97780.98260.98640.98960.99200.99400.99550.99660.99750.99820.50800.54780.58710.62550.66280.69850.73240.76420.79390.82120.84610.86860.88880.90660.92220.93570.94740.95730.96560.97260.97800.98300.98680.98980.99220.99410.99560.99670.99760.99820.51200.55170.59100.62930.66640.70190.73570.76780.79670.82380.84850.87080.89070.90820.92360.93700.94840.95820.96640.97220.97880.98340.98710.99010.99250.99430.99570.99680.99770.99830.51600.55570.59480.63310.67000.70540.73890.77030.79950.82640.85080.87290.89250.90990.92510.93820.94950.95910.96710.97380.97930.98380.98740.99040.99270.99450.99590.99690.99770.99840.51990.55960.59870.63680.67360.70880.74220.77340.80230.82890.85310.87490.89440.91150.92650.93940.95050.95990.96180.97440.97980.98420.98780.99060.99290.99460.99600.99700.99780.99840.52390.56860.60260.64060.67720...