大体积墩台混凝土施工技术

大体积墩台混凝土施工技术（3）采用松香热聚物AE作为防冻剂，增强混凝土的防冻性能;（4）采用二级以上粉煤灰替代部分水泥来增强混凝土的和易性;普硅水泥425水砂石减水剂AEUEA粉煤灰4005686.630.0164040龄期3690.570.540.490.390.250.220.180.140.110.10Q——每千克水泥水化热量（J/kg取377J/kg;e——常数值，为2.718;t——龄期（天）;浇筑温度(℃)m龄期（天）1234567890.3620.3040.5150.6620.7650.8360.8860.9210.9450.962浇筑温度(℃)m龄期（天）0.3620.9730.9810.9870.9910.9940.9960.9970.9980.999龄期（天）13691-e-mt0.3040.6620.8860.9620.9870.9960.99943.358.063.064.665.265.565.565.565.565.5T=T(t)龄期（天）3690.570.540.490.390.250.220.180.140.110.10T(t).37.335.332.125.59.27.26.5注:T(t).T=To+T(t)(t)Tmax——混凝土内部中心最高温度(℃);龄期（天）369中心温度℃57.355.352.145.536.434.431.829.227.226.5外温度20℃,不保温即可满足内外温差小于25℃的要求，因此龄期（天）369表面温度℃49.848.547.345.142.327.625.321.921.821.7温差绝对值℃7.56.84.80.45.96.86.57.35.44.8y(t)——非标准状态下混凝土任意龄期（天）的收缩变形值;M1～M10——考虑各种非标准条件，与水泥品种细度、骨料品种、水灰 M1=1.0普通水泥根据龄期取值M2=1.35水泥细度(5000)相对湿度(60%)M3=1.0骨料为花岗岩γ=(2×2+20)/(2×20)=0.6M4=1.0水灰比0.4机械振捣M5=1.2水泥浆量(25%)aAa/EbAb)]配筋率为0.06a=2.0×105Eb=3.25×104)369212427y(30)=1.326×10-4y(18)=0.843×10-4y(27)=1.213×10-4y(t)——各龄期(d)混凝土收缩相对变形369-1.77-3.26-4.62-5.90-7.13-8.43-9.69-10.9-12.1-13.3E(t)=Ec(1-e-0.09t)E(t)——混凝土从浇筑到计算时的弹性模量(N/mm2);E(3)=0.77×104E(6)=1.36×104E(9)=1.5×104E(12)=2.15×104E(15)=2.41×104E(18)=2.61×104E(21)=2.76×104E(24)=2.88×104E(27)=2.96×104E(30)=3.03×104(t)(t)/(1-ν)]（式-7）(t)——混凝土截面中心与表面之间的温差(℃)。不同龄期（d）369(t)℃7.56.84.80.45.96.86.57.35.44.8E(t)40.772.152.412.612.762.882.963.030.4530.7250.5650.067p(18)=90%，p(21)=92%，p(24)=95%，p(27)=97%，p(30)=100%。K(t)=f(t)/(t)龄期（天）3690.862.042.092.150.4530.7250.5650.067K(t)2.6625.67(t)(t)R（式-9）0+2/3T(t)+Ty(t)-Th（式-10）E(t)——混凝土从浇筑后至计算时的弹性模量(N/mm2);S(t)——考虑徐变影响的松弛系数，一般取0.3～0.5;R——混凝土的外约束系数,取0.5;龄期（天）369-1.77-3.26-4.62-5.90-7.13-8.43-9.69-10.9-12.1-13.343.358.063.064.665.265.565.565.565.565.5(t)℃27.135.137.437.236.335.234.032.831.630.4E(t)40.772.152.412.612.762.882.963.03S(t)0.1860.2080.2140.2150.2330.2520.3010.4360.5700.2280.5840.7061.0121.1991.3621.6622.4233.1365.418f(t)0.862.042.092.15K(t)3.772.022.140.840.670.4墩台混凝土拆除侧模后，底模安排在混凝土强度达到9221天）16℃左右。否则就要采取保温或降温措施,侧模板加工制作，按要求