承台大体积混凝土温控

1、.阳逻长江大桥北标段主塔承台大体积混凝土配合比设计及温控施工方案武汉理工大学二OO四年三月一、 工程概况阳逻长江大桥主塔墩承台平面尺寸为21.6m×21.6m,高6m,混凝土设计标号为C30。承台属重要的大体积混凝土结构，混凝土方量相当大，必须采取专门措施防止因为混凝土水化热温升而出现温度裂缝，以满足设计要求，保证大桥的长期安全使用。受大桥局阳逻大桥项目经理部的委托，武汉理工大学对阳逻大桥承台大体积混凝土进行了温控计算，得出了大体积混凝土内部仿真温度场和应力场，根据计算结果制定了承台不出现有害温度裂缝的温控标准，并以此制定了相应的温控措施。温控计算采用有限元程序大体积砼施工期温度场及

2、温度应力场计算程序包进行。二、承台部位C30强度等级大体积混凝土配合比表1编号水(kg/m3)水泥(kg/m3)粉煤灰(kg/m3)砂(kg/m3)石(kg/m3)减水剂(kg/m3)坍落度(cm)28d抗压强度(Mpa)0h2h117233010071510739.422.51843.221753508071410719.4211646.5317230013071510739.4231838.64165280*12072810959.021.51740.3注：减水剂引入的水量已包含在用水量中。原材料：水泥：第1、2、3组：葛洲坝水泥厂矿渣PS32.5#水泥； 第4组：华新PS32.5#矿渣水

3、泥;粉煤灰：阳逻电厂I级灰,需水量比92%，烧失量2.9%;砂：巴河中砂2.3-3.1;石：5-31.5mm碎石;减水剂：武钢浩源FDN-9001高效减水剂（水剂）。 考虑混凝土强度、工作性能及经济性，建议若使用葛洲坝矿渣PS32.5水泥选择第1组配方，若使用华新PS32.5矿渣水泥选择第4组配方。三、 温控计算1 计算条件1.1 施工时间及进度等施工时间：按4月中下旬。施工进度：3m/层，浇筑时间1-2d；间歇期8d。通水方式及时间：砼浇筑到各层冷却水管标高后即开始通水，通水时间15d，通水水温17.4；为防止冬季混凝土内外温差过大，12月1日进行后期通水，通水时间按混凝土温度降到16.5控

4、制，通水水温14.0。浇筑温度：20。放热系数：草袋保温（保温时间2个月）时=3.2W/m2·，其它时间=14W/m2·。导温系数：0.07 m2/d。线膨胀系数：8.9×10-6/.1.2 混凝土力学参数混凝土容重 2400kg/m3混凝土绝热温升：混凝土弹性模量：混凝土徐变度：1. 3气温 ，另外加3辐射热 ，起点为1月1日。 2 计算结果根据表1混凝土配合比第1组计算（水泥为葛洲坝水泥厂矿渣PS32.5#水泥）。2.1 温度 第一层浇筑第5天板内达到最高温度47.8，第二层浇筑第5天板内达到最高温度48.5。中心点温度历时过程见图1。冬季内外温差小于20。(

5、时间原点为2004年元月1日，4月20日开始浇筑施工时为图表上第111天，浇筑温度为20)。图1 温度历时过程线表2 各部位混凝土内温度随时间变化值时间距顶面4.5m处(距底面1.5m)温度（）距顶面1.5m处(距底面4.5m)温度（）顶面温度（）0000100002000030000400005000060000700008000090000100000110000111（即4月20日，开始浇筑第一层）200011237.540011343.940011446.720011547.760011647.820011747.30011846.4400119（即4月28日，开始浇筑第二层）45.3

6、7202012045.3137.5633.6512145.1244.0336.7312244.8946.9837.3212344.6948.2337.0812444.5348.5436.5212544.4148.2735.8512644.3147.6635.1512744.2146.8434.4712844.1147.0734.5112944.0147.1934.4713043.947.2234.413143.7947.1834.3113243.6947.0934.2213343.5946.9734.1413443.4946.8334.0613543.4146.6633.9813643.324

7、6.4833.9113743.2446.2833.8513843.1546.0833.7913943.0745.8733.7414042.9945.6633.714142.945.4533.6714242.8245.2333.6414342.7445.0233.6114442.6544.8133.5914542.5744.633.5814642.4844.3933.5714742.3944.1933.5614842.343.9933.5614942.2143.833.5615042.1243.633.5615142.0343.4233.5715241.9443.2333.5715341.854

8、3.0533.5815441.7642.8833.615541.6642.7133.6115641.5742.5433.6315741.4742.3833.6415841.3842.2233.6615941.2842.0633.6816041.1941.9133.716141.0941.7633.721624141.6233.7416340.941.4833.7616440.8141.3433.7816540.7141.2133.816640.6241.0833.8216740.5240.9533.8416840.4340.8333.8616940.3340.7133.8917040.2440

9、.5933.9117140.1540.4733.9217240.0540.3633.9417339.9640.2533.9617439.8740.1433.9817539.7840.0433.9917639.6939.9434.0117739.639.8434.0217839.5139.7434.0417939.4239.6434.0518039.3339.5532.7818139.2439.4532.518239.1539.3432.4218339.0739.2232.3918438.9839.0932.3918538.8938.9632.3918638.8138.8332.3918738.

10、7338.732.418838.6438.5832.4118938.5638.4632.4219038.4838.3432.4219138.3938.2232.4319238.3138.1132.4319338.2338.0132.4319438.1537.932.4319538.0737.832.4219637.9937.732.4219737.9137.6132.4119837.8337.5132.3919937.7537.4232.3820037.6737.3332.3620137.637.2532.3420237.5237.1632.3120337.4437.0732.2920437.

11、3636.9932.2620537.2936.9132.2220637.2136.8332.1920737.1436.7432.1520837.0636.6632.120936.9936.5832.0621036.9136.532.0121136.8436.4231.9621236.7636.3531.921336.6936.2731.8421436.6236.1931.7821536.5536.1131.7221636.4736.0331.6521736.435.9531.5821836.3335.8731.5121936.2635.7931.4322036.1935.7131.352213

12、6.1235.6331.2722236.0535.5531.1822335.9835.4731.0922435.9135.393122535.8535.3130.922635.7835.2330.8122735.7135.1430.722835.6435.0630.622935.5834.9730.4923035.5134.8930.3823135.4534.830.2723235.3834.7230.1523335.3134.6330.0423435.2534.5429.9223535.1834.4529.7923635.1234.3629.6623735.0634.2729.5423834

13、.9934.1729.423934.9334.0829.2724034.8733.9929.1324134.833.8928.9924234.7433.7928.8524334.6833.728.7124434.6133.628.5624534.5533.528.4124634.4933.428.2624734.4333.328.124834.3733.1927.9524934.333.0927.7925034.2432.9927.6325134.1832.8827.4625234.1232.7727.325334.0632.6627.132543432.5526.9625533.9432.4

14、426.7925633.8732.3326.6225733.8132.2226.4425833.7532.1126.2725933.6931.9926.0926033.6331.8825.9126133.5731.7625.7326233.5131.6425.5426333.4531.5225.3626433.3931.425.1726533.3231.2824.9826633.2631.1624.7926733.231.0324.626833.1430.9124.4126933.0830.7824.2227033.0230.6624.0227132.9630.5323.8327232.930

15、.423.6327332.8330.2723.4327432.7730.1423.2327532.7130.0123.0327632.6529.8822.8327732.5929.7422.6327832.5229.6122.4327932.4629.4822.2328032.429.3422.0228132.3429.221.8228232.2729.0721.6128332.2128.9321.4128432.1528.7921.228532.0828.652128632.0228.5120.7928731.9628.3720.5928831.8928.2320.3828931.8328.

16、0820.1729031.7627.9419.9729131.727.819.7629231.6327.6519.5529331.5727.5119.3529431.527.3619.1429531.4427.2218.9429631.3727.0718.7329731.326.9218.5329831.2426.7818.3229931.1726.6318.1230031.126.4817.9130131.0426.3317.7130230.9726.1817.5130330.926.0417.3130430.8325.8917.1130530.7725.7416.9130630.725.5

17、916.7130730.6325.4416.5130830.5625.2916.3130930.4925.1416.1231030.4224.9915.9231130.3524.8415.7331230.2824.6915.5331330.2124.5415.3431430.1424.3915.1531530.0724.2414.973163024.0914.7831729.9323.9414.5931829.8623.7914.4131929.7923.6414.2332029.7223.4914.0532129.6423.3413.8732229.5723.1913.6932329.523

18、.0413.5232429.4322.8913.3432529.3522.7513.1732629.2822.61332729.2122.4512.8332829.1322.3112.6732929.0622.1612.5133028.9822.0212.3433128.9121.8712.1933228.8421.7312.0333328.7621.5811.8833428.6921.4411.7233528.0321.0111.5733627.420.611.4233726.820.2111.2733826.2219.8411.1233925.6819.510.9634025.1619.1

19、610.8134124.6718.8410.6634224.218.5410.5134323.7618.2410.3634423.3517.9810.2234522.9517.7310.0934622.5817.489.9634722.2217.259.8334821.8917.029.7134921.5716.89.5935021.2616.589.4735120.9716.479.3535220.716.329.2435320.4416.159.1335420.1915.979.0335519.9615.88.9335619.7315.628.8335719.5215.458.743581

20、9.3215.288.6535919.1215.138.5636018.9414.998.4836118.7614.858.436218.5914.728.3336318.4414.588.2536418.2814.458.1936518.1414.318.123661814.198.0636717.8714.07836817.7413.957.9536917.6213.847.937017.5113.737.8637117.413.627.8137217.2913.527.7737317.213.427.7437417.1113.327.7137517.0213.227.6837616.95

21、13.137.6537716.8813.047.6337816.8112.967.6237916.7412.887.638016.712.87.5938116.6512.727.5938216.6112.657.5838316.5712.577.5938416.5312.517.5938516.4912.447.638616.4512.387.6138716.4112.327.6338816.4712.267.6438916.4812.27.6739016.4812.157.6939116.4712.17.7239216.4512.057.7639316.42127.7939416.411.9

22、67.8339516.3711.927.8839616.3711.887.9239716.3711.847.9739816.3811.818.0339916.3911.788.0840016.411.758.1540116.4111.728.2140216.4211.78.2840316.4211.688.3540416.4311.668.4240516.4411.648.540616.4411.638.5840716.4511.628.6640816.4511.618.7540916.4511.68.8441016.4511.598.9341116.4611.599.0341216.4511

23、.599.1341316.4511.69.2341416.4511.69.3441516.4511.619.4541616.4511.629.5641716.4411.639.6741816.4411.659.7941916.4311.669.9142016.4311.6810.0342116.4211.710.1642216.4211.7310.2942316.4111.7510.4242416.411.7810.5542516.411.8110.6942616.3911.8510.8342716.3811.8810.9742816.3811.9211.1142916.3711.9611.2

24、643016.361211.4143116.3512.0411.5643216.3512.0911.7143316.3412.1411.8743416.3312.1912.0343516.3312.2412.1943616.3212.2912.3543716.3112.3512.5143816.3112.4112.6843916.312.4712.8544016.2912.5313.0244116.2912.5913.1944216.2812.6613.3744316.2812.7213.5444416.2712.7913.7244516.2712.8613.944616.2612.9314.

25、0844716.2613.0114.2644816.2613.0814.4544916.2513.1614.6345016.2513.2414.8245116.2513.3215.0145216.2513.415.245316.2413.4915.3945416.2413.5715.5845516.2413.6615.7745616.2413.7515.9745716.2413.8416.1645816.2413.9316.3645916.2514.0216.5546016.2514.1116.7546116.2514.2116.9546216.2514.3117.1546316.2614.4

26、17.3546416.2614.517.5546516.2614.617.7546616.2714.717.9546716.2714.8118.1546816.2814.9118.3646916.2915.0218.5647016.2915.1218.7647116.315.2318.9647216.3115.3419.1747316.3215.4519.3747416.3315.5619.5747516.3415.6719.7847616.3515.7819.9847716.3615.8920.1847816.3716.0120.3847916.3816.1220.5948016.416.2

27、420.7948116.4116.3520.9948216.4216.4721.1948316.4416.5921.3948416.4516.721.5948516.4716.8221.7948616.4916.9421.9948716.517.0622.1948816.5217.1822.3848916.5417.322.5849016.5617.4322.7749116.5817.5522.9749216.617.6723.1649316.6217.7923.3549416.6417.9123.5449516.6618.0423.7349616.6818.1623.9249716.7118

28、.2824.149816.7318.4124.2949916.7518.5324.4750016.7818.6624.6550116.818.7824.8450216.8318.925.0150316.8619.0325.1950416.8819.1525.3750516.9119.2825.5450616.9419.425.7150716.9719.5225.885081719.6526.0550917.0319.7726.2251017.0619.8926.3851117.0920.0126.5451217.1220.1426.751317.1520.2626.8651417.1820.3

29、827.0251517.2120.527.1751617.2520.6227.3251717.2820.7427.4751817.3120.8627.6151917.3520.9827.7652017.3821.127.952117.4221.2228.0452217.4521.3428.1752317.4921.4528.3152417.5321.5728.4452517.5621.6828.5752617.621.828.6952717.6421.9128.8152817.6822.0228.9352917.7122.1429.0553017.7522.2529.1653117.7922.

30、3629.2753217.8322.4729.3853317.8722.5729.4953417.9122.6829.5953517.9522.7929.6953617.9922.8929.7953718.0322.9929.8853818.0723.129.9753918.1223.230.0654018.1623.330.1454118.223.430.2254218.2423.4930.354318.2823.5930.3754418.3323.6930.4454518.3723.7830.5154618.4123.8730.5754718.4623.9630.6354818.524.0

31、530.6954918.5424.1430.7555018.5924.2230.855118.6324.3130.8455218.6724.3930.8955318.7224.4730.9355418.7624.5530.9755518.8124.633155618.8524.7131.0355718.924.7931.0655818.9424.8631.0855918.9924.9331.156019.032531.1256119.0725.0731.1356219.1225.1431.1456319.1625.231.1556419.2125.2631.1556519.2525.3331.

32、1556619.325.3931.1456719.3425.4431.1356819.3925.531.1256919.4325.5531.1157019.4725.631.0957119.5225.6531.0757219.5625.731.0457319.6125.7531.0157419.6525.7930.9857519.6925.8430.9557619.7425.8830.9157719.7825.9230.8657819.8225.9530.8257919.8725.9930.7758019.9126.0230.7258119.9526.0530.6658219.9926.083

33、0.658320.0326.130.5458420.0826.1330.4758520.1226.1530.458620.1626.1730.3358720.226.1930.2558820.2426.2130.1858920.2826.2230.0959020.3226.2330.0159120.3626.2429.9259220.426.2529.8359320.4426.2629.7359420.4826.2629.6459520.5126.2629.5359620.5526.2629.4359720.5926.2629.3259820.6326.2529.2159920.6626.25

34、29.160020.726.2428.9960120.7326.2328.8760220.7726.2128.7560320.826.228.6260420.8426.1828.560520.8726.1628.3760620.9126.1428.2360720.9426.1228.160820.9726.0927.966092126.0727.8261021.0326.0427.6861121.0726.0127.5361221.125.9727.3961321.1325.9427.2461421.1525.927.0961521.1825.8626.9361621.2125.8226.78

35、61721.2425.7826.6261821.2725.7326.4661921.2925.6926.2962021.3225.6426.1362121.3425.5925.9662221.3725.5425.7962321.3925.4825.6262421.4125.4325.4562521.4425.3725.2762621.4625.3125.162721.4825.2524.9262821.525.1824.7462921.5225.1224.5663021.5425.0524.3863121.5624.9824.1963221.5824.9124.0163321.5924.842

36、3.8263421.6124.7723.6363521.6324.6923.4463621.6424.6223.2563721.6624.5423.0663821.6724.4622.8763921.6824.3822.6764021.724.322.4864121.7124.2122.2864221.7224.1322.0964321.7324.0421.8964421.7423.9521.6964521.7523.8621.4964621.7623.7721.2964721.7623.6821.0964821.7723.5820.8964921.7823.4920.6965021.7823

37、.3920.4965121.7923.320.2965221.7923.220.0965321.7923.119.8965421.82319.6865521.822.919.4865621.822.7919.2865721.822.6919.0865821.822.5818.8765921.822.4818.6766021.822.3718.4766121.7922.2618.2766221.7922.1518.0766321.7922.0417.8766421.7821.9317.6766521.7821.8217.4766621.7721.7117.2766721.7621.617.076

38、6821.7621.4916.8766921.7521.3716.6767021.7421.2616.4867121.7321.1416.2867221.7221.0316.0967321.7120.9115.8967421.6920.815.767521.6820.6815.5167621.6720.5615.3267721.6620.4415.1367821.6420.3314.9467921.6320.2114.7568021.6120.0914.5768121.5919.9714.3868221.5819.8514.268321.5619.7314.0268421.5419.6113.

39、8468521.5219.513.6668621.519.3813.4968721.4819.2613.3168821.4619.1413.1468921.4419.0212.9769021.4118.912.869121.3918.7812.6469221.3718.6612.4769321.3418.5412.3169421.3218.4312.1569521.2918.3111.9969621.2718.1911.8369721.2418.0711.6869821.2117.9611.5369921.1917.8411.3870021.1617.7211.2370121.1317.611

40、1.0970221.117.4910.9570321.0717.3810.8170421.0417.2710.6770521.0117.1510.5470620.9817.0410.470720.9516.9310.2770820.9216.8210.1570920.8816.7110.0271020.8516.69.971120.8216.499.7971220.7816.389.6771320.7516.279.5671420.7216.179.4571520.6816.069.3471620.6515.969.2471720.6115.869.1471820.5715.759.04719

41、20.5415.658.9572020.515.558.86 2.2砼内部应力主要特征承台内部不同龄期的最大温度主拉应力见下表所示；表3 第一层最大温度主拉应力 龄期（d）714284565应力（MPa）1.072.102.132.242.38表4 第二层最大温度主拉应力龄期（d）714284868应力（MPa）1.001.732.322.632.69表5 承台C30混凝土劈裂抗拉强度龄期（d）71428Rpl（MPa）1.903.153.82根据表3、表4的计算结果和表5的混凝土劈裂抗拉强度测试结果可知承台大体积砼在施工期内有1.4-1.5的抗裂安全系数，在采取有效的温控措施并合理施工后，可

42、以防止承台砼产生有害温度裂缝。四、温度控制标准根据计算成果，为保证承台在施工期内不出现有害温度裂缝，应采取如下温控标准：（1） 混凝土浇筑温度不超过25；（2） 混凝土在浇筑温度基础上的最大水化热温升不超过31；（3） 混凝土内表温差不超过28；（4） 混凝土降温速率不超过1.5/d。五、温控措施1.混凝土原材料及质量控制：（1）水泥：采用葛洲坝水泥厂生产的PS32.5矿渣水泥，或采用华新水泥厂生产的PS32.5矿渣水泥。水泥散袋或袋装入场，水泥使用温度不得超过50，否则须采取措施降低水泥温度，如可要求水泥生产厂家放置一段时间后发货。袋装水泥入场后应按品种、标号、出厂日期分别存放，同时应采取措

43、施防止受潮。水泥应分批检验，质量应稳定。若存放期超过3个月应重新检验。（2）粉煤灰：采用阳逻电厂I级粉煤灰，质量应符合用于水泥和混凝土中的粉煤灰（GB159691）的规定。（3）砂：采用湖北巴河产中砂，含泥量2%，细度模数2.33.1，属II区级配范围，其它指标必须符合规范规定。砂来源必须稳定，砂入场后应分批检验。（4）石：采用碎石。石子必须为530mm连续级配，级配应优良，来源应稳定。石子必须分批检验并严格控制其含泥量不超过1.0%。如果达不到要求，必须用水冲洗合格后才能使用，其他指示标必须符合规范要求。（5）外加剂：应采用缓凝型高效减水剂，具体品种施工方初步定为武钢浩源外加剂厂FDN-9001型高效减水剂(水剂)。外加剂应分批检验，如发现异常应及时报告。（6）水：拌和用水的水质需通过严格检验并符合有关规范规定。2.混凝土浇筑温度的控制混凝土出搅拌机后，经运输、平仓、振捣等过程后距离表面510cm处的温度为浇筑温度，应控制混凝土浇筑温度不超过250C。若浇筑温度超