C30 → fcu=30, fck,cyl=24, fck,prism=20.06, fc=14.33 MPa fck,cyl = 0.8·30 = 24;fck,prism = 0.88·0.76·30 = 20.064;fc = 20.064/1.4 = 14.33 MPa。{"result":"Concrete grade C30. fcu,k = 30.00 MPa, fck,cyl = 0.8·fcu = 24.00 MPa, fck,prism = 0.88·0.76·fcu = 20.06 MPa, fc = fck,prism/1.4 = 14.33 MPa. Ratio fck,cyl/fcu = 0.80.","metadata":{"input":{"inputType":"grade","value":30},"result":{"grade":"C30","fcu":30,"fcuUnit":"MPa","fckCylinder":24,"fckPrism":20.06,"fc":14.33,"strengthUnit":"MPa","cylToCubeRatio":0.8,"prismFactor":0.6688,"gammaC":1.4}}}
圆柱 fck,cyl = 25 MPa → fcu = 31.25 MPa(非标准) fcu = 25/0.8 = 31.25。最接近的标准等级向下取 C30。fck,prism ≈ 20.9 MPa;fc ≈ 14.93 MPa。{"result":"Input fck,cyl = 25.00 MPa → fcu = 25/0.8 = 31.25 MPa (non-standard grade, closest standard ≤ is C30). fck,cyl = 25.00 MPa, fck,prism = 0.88·0.76·fcu = 20.90 MPa, fc = fck,prism/1.4 = 14.93 MPa. Ratio fck,cyl/fcu = 0.80.","metadata":{"input":{"inputType":"cylinder","value":25},"result":{"grade":"non-standard (fcu=31.25)","fcu":31.25,"fcuUnit":"MPa","fckCylinder":25,"fckPrism":20.9,"fc":14.93,"strengthUnit":"MPa","cylToCubeRatio":0.8,"prismFactor":0.6688,"gammaC":1.4,"closestStandardGrade":"C30"}}}