. . 混凝土强度设计值（N/mm2）强度种类混凝土强度等级C15C20C25C30C35C40C45C50C55C60C65C70C75C80fc7.29.6 11.914.316.719.121.123.125.327.529.731.833.835.9ft0.911.101.271.431.571.711.801.891.962.042.092.142.182.22混凝土强度标准值（N/mm2）强度种类符号混 凝 土 强 度 等 级C7.5C10C15C20C25C30C35C40C45C50C55C60轴心抗压fck56.7 10 13.5 17 20 23.5 27 29.5 32 34 36 弯曲抗压fcmk5.5 7.5 11 15 18.5 22 26 29.5 32.5 35 37.5 39.5 抗 拉ftk0.75 0.9 1.2 1.5 1.75 2 2.25 2.45 2.6 2.75 2.85 2.95 纵向受力钢筋混凝土保护层最小厚度（mm）环境类别板、墙、壳梁、柱、杆柱C20C25C45C50C20C25C45C50C20C25C45C50一201515252020二a252020302525b302520403530三353025454035注：基础中纵向受力钢筋的混凝土保护层厚度不应小于40mm，当无垫层时不应小于70mm。现浇钢筋混凝土房屋适用最大高度（m）结构体系抗震设防烈度6789框 架60554525框架抗剪墙13012010050抗震墙14012010060部分框支抗震墙12010080不应采用框架核心筒15013010070筒中筒18015012080板柱抗震墙403530不应采用注：1.房屋高度指室外地面到主要屋面板板顶的高度（不包括局部突出屋顶部分）；2.框架核心筒结构指周边稀柱框架与核心筒组成的结构；3.部分框支抗震墙结构指首层或底部两层框支抗震墙结构；4.乙类建筑可按本地区抗震设防烈度确定适用的最大高度；5.超过表高度的房屋，应进行专门研究和论证，采取有效的加强措施。钢筋的计算截面面积与公称质量表直径d（mm）不同根数直径的计算截面面积（mm2）单根钢筋公称质量（kg/m）12345678934566.57.112.619.628.333.214.125.139576621.237.75985100 28.350.37911313335.362.89814116642.475.4118170199 49.588.0137198232 56.5100.5157226265 63.6113.1177254299 0.05550.09860.1540.2220.26088.210121450.352.878.5113.1153.9 101106157226308 151158236339462 201211314452616 251264393565770 302317471679924 3523705507921078 4024226289051232 45247570710181385 0.3950.4150.6170.8881.208 1618202225201.1254.5314.2380.1490.9402509628760982 60376394211401473 8041018125715211963 10051272157119012454 12061527188522812945 14071781219926613436 16082036251330413927 18102290282734214418 1.5781.9982.4662.9843.853 28323640615.8804.21017.91256.6 1232160820362513 1847241330543770 2463321740725027 3079402150896283 3695482561077540 4310563071258796 49266434814310053 55427238916111310 4.8346.3137.9909.865 每米板宽的钢筋截面面积表 钢筋间距（mm）当钢筋直径（mm）为以下数值时的钢筋截面面积（mm2）44.55681012141618202225707580901001801681571401262272121991771592802622452181964043773533142837186706285595031122104798287378516161508141412571131219920531924171015392872268125132234201136353393318128272545448841893927349131425430506847524224380170126545613654544909110120125130140150114105101979084145133127122114106178164157151140131257236226217202188457419402387359335714654628604561524102894290587080875413991283123211841100102618281676160815471436134023132121203619571818169628562618251324172244209434563168304129242715253444624091392737763506327216017017518019020079747270666399949188848012311511210910398177166162157149141314296287279265251491462449436413392707665646628595565962906880855810770125711831149111710581005159014971454141413391272196318481795174516531571237622362172211220011901306828872805272725842454250300504264537965113942011683142624523776165138046701018848125710471521126719631636钢筋间距44.55681012141618202225混凝土板每m最小配筋率配筋面积级钢（最小配箍率取0.45ft/fc与0.2%取较大值）板厚C20（0.236%）C25（0.272%）C30（0.306%）C35（0.336%）80189218245269100236272306336120283326367403130307354398437150354408459504180425489551605混凝土板每m最小配筋率配筋面积级钢板厚C20（0.2%）C25（0.2%）C30（0.215%）C35（0.236%）80160160172189100200200215236120240240258283130260260280307150300300323354180360360387425混凝土板每m最小配筋率配筋面积级钢板厚C20（0.2%）C25（0.2%）C30（0.2%）C35（0.2%）80160160160160100200200200200120240240240240130260260260260150300300300300180360360360360梁钢筋排成一排时的钢筋最 多根数梁宽（mm）2002503