承臺大體積混凝土溫控

1、.陽邏長江大橋北標(biāo)段主塔承臺大體積混凝土配合比設(shè)計及溫控施工方案武漢理工大學(xué)二OO四年三月一、 工程概況陽邏長江大橋主塔墩承臺平面尺寸為21.6m×21.6m,高6m,混凝土設(shè)計標(biāo)號為C30。承臺屬重要的大體積混凝土結(jié)構(gòu)，混凝土方量相當(dāng)大，必須采取專門措施防止因為混凝土水化熱溫升而出現(xiàn)溫度裂縫，以滿足設(shè)計要求，保證大橋的長期安全使用。受大橋局陽邏大橋項目經(jīng)理部的委托，武漢理工大學(xué)對陽邏大橋承臺大體積混凝土進行了溫控計算，得出了大體積混凝土內(nèi)部仿真溫度場和應(yīng)力場，根據(jù)計算結(jié)果制定了承臺不出現(xiàn)有害溫度裂縫的溫控標(biāo)準(zhǔn)，并以此制定了相應(yīng)的溫控措施。溫控計算采用有限元程序大體積砼施工期溫度場及

2、溫度應(yīng)力場計算程序包進行。二、承臺部位C30強度等級大體積混凝土配合比表1編號水(kg/m3)水泥(kg/m3)粉煤灰(kg/m3)砂(kg/m3)石(kg/m3)減水劑(kg/m3)坍落度(cm)28d抗壓強度(Mpa)0h2h117233010071510739.422.51843.221753508071410719.4211646.5317230013071510739.4231838.64165280*12072810959.021.51740.3注：減水劑引入的水量已包含在用水量中。原材料：水泥：第1、2、3組：葛洲壩水泥廠礦渣PS32.5#水泥； 第4組：華新PS32.5#礦渣水

3、泥;粉煤灰：陽邏電廠I級灰,需水量比92%，燒失量2.9%;砂：巴河中砂2.3-3.1;石：5-31.5mm碎石;減水劑：武鋼浩源FDN-9001高效減水劑（水劑）。 考慮混凝土強度、工作性能及經(jīng)濟性，建議若使用葛洲壩礦渣PS32.5水泥選擇第1組配方，若使用華新PS32.5礦渣水泥選擇第4組配方。三、 溫控計算1 計算條件1.1 施工時間及進度等施工時間：按4月中下旬。施工進度：3m/層，澆筑時間1-2d；間歇期8d。通水方式及時間：砼澆筑到各層冷卻水管標(biāo)高后即開始通水，通水時間15d，通水水溫17.4；為防止冬季混凝土內(nèi)外溫差過大，12月1日進行后期通水，通水時間按混凝土溫度降到16.5控

4、制，通水水溫14.0。澆筑溫度：20。放熱系數(shù)：草袋保溫（保溫時間2個月）時=3.2W/m2·，其它時間=14W/m2·。導(dǎo)溫系數(shù)：0.07 m2/d。線膨脹系數(shù)：8.9×10-6/.1.2 混凝土力學(xué)參數(shù)混凝土容重 2400kg/m3混凝土絕熱溫升：混凝土彈性模量：混凝土徐變度：1. 3氣溫 ，另外加3輻射熱 ，起點為1月1日。 2 計算結(jié)果根據(jù)表1混凝土配合比第1組計算（水泥為葛洲壩水泥廠礦渣PS32.5#水泥）。2.1 溫度 第一層澆筑第5天板內(nèi)達到最高溫度47.8，第二層澆筑第5天板內(nèi)達到最高溫度48.5。中心點溫度歷時過程見圖1。冬季內(nèi)外溫差小于20。(

5、時間原點為2004年元月1日，4月20日開始澆筑施工時為圖表上第111天，澆筑溫度為20)。圖1 溫度歷時過程線表2 各部位混凝土內(nèi)溫度隨時間變化值時間距頂面4.5m處(距底面1.5m)溫度（）距頂面1.5m處(距底面4.5m)溫度（）頂面溫度（）0000100002000030000400005000060000700008000090000100000110000111（即4月20日，開始澆筑第一層）200011237.540011343.940011446.720011547.760011647.820011747.30011846.4400119（即4月28日，開始澆筑第二層）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砼內(nèi)部應(yīng)力主要特征承臺內(nèi)部不同齡期的最大溫度主拉應(yīng)力見下表所示；表3 第一層最大溫度主拉應(yīng)力 齡期（d）714284565應(yīng)力（MPa）1.072.102.132.242.38表4 第二層最大溫度主拉應(yīng)力齡期（d）714284868應(yīng)力（MPa）1.001.732.322.632.69表5 承臺C30混凝土劈裂抗拉強度齡期（d）71428Rpl（MPa）1.903.153.82根據(jù)表3、表4的計算結(jié)果和表5的混凝土劈裂抗拉強度測試結(jié)果可知承臺大體積砼在施工期內(nèi)有1.4-1.5的抗裂安全系數(shù)，在采取有效的溫控措施并合理施工后，可

42、以防止承臺砼產(chǎn)生有害溫度裂縫。四、溫度控制標(biāo)準(zhǔn)根據(jù)計算成果，為保證承臺在施工期內(nèi)不出現(xiàn)有害溫度裂縫，應(yīng)采取如下溫控標(biāo)準(zhǔn)：（1） 混凝土澆筑溫度不超過25；（2） 混凝土在澆筑溫度基礎(chǔ)上的最大水化熱溫升不超過31；（3） 混凝土內(nèi)表溫差不超過28；（4） 混凝土降溫速率不超過1.5/d。五、溫控措施1.混凝土原材料及質(zhì)量控制：（1）水泥：采用葛洲壩水泥廠生產(chǎn)的PS32.5礦渣水泥，或采用華新水泥廠生產(chǎn)的PS32.5礦渣水泥。水泥散袋或袋裝入場，水泥使用溫度不得超過50，否則須采取措施降低水泥溫度，如可要求水泥生產(chǎn)廠家放置一段時間后發(fā)貨。袋裝水泥入場后應(yīng)按品種、標(biāo)號、出廠日期分別存放，同時應(yīng)采取措

43、施防止受潮。水泥應(yīng)分批檢驗，質(zhì)量應(yīng)穩(wěn)定。若存放期超過3個月應(yīng)重新檢驗。（2）粉煤灰：采用陽邏電廠I級粉煤灰，質(zhì)量應(yīng)符合用于水泥和混凝土中的粉煤灰（GB159691）的規(guī)定。（3）砂：采用湖北巴河產(chǎn)中砂，含泥量2%，細(xì)度模數(shù)2.33.1，屬II區(qū)級配范圍，其它指標(biāo)必須符合規(guī)范規(guī)定。砂來源必須穩(wěn)定，砂入場后應(yīng)分批檢驗。（4）石：采用碎石。石子必須為530mm連續(xù)級配，級配應(yīng)優(yōu)良，來源應(yīng)穩(wěn)定。石子必須分批檢驗并嚴(yán)格控制其含泥量不超過1.0%。如果達不到要求，必須用水沖洗合格后才能使用，其他指示標(biāo)必須符合規(guī)范要求。（5）外加劑：應(yīng)采用緩凝型高效減水劑，具體品種施工方初步定為武鋼浩源外加劑廠FDN-9001型高效減水劑(水劑)。外加劑應(yīng)分批檢驗，如發(fā)現(xiàn)異常應(yīng)及時報告。（6）水：拌和用水的水質(zhì)需通過嚴(yán)格檢驗并符合有關(guān)規(guī)范規(guī)定。2.混凝土澆筑溫度的控制混凝土出攪拌機后，經(jīng)運輸、平倉、振搗等過程后距離表面510cm處的溫度為澆筑溫度，應(yīng)控制混凝土澆筑溫度不超過250C。若澆筑溫度超