大体积高强度混凝土空心墩柱温控研究

Research on Temperature Control of Large Volume High-strength Concrete Hollow Piers

大体积高强度混凝土空心墩柱构形复杂、混凝土水化热规律研究较少。文中以马鞍山公铁两用长江大桥主桥塔柱施工为背景,运用有限元软件midas Civil建立模型并分析此类高强度混凝土空心墩柱结构内部温度场分布规律,结合实测数据分析冷却水管系统的作用。结果表明,高强度混凝土空心墩柱与常规形状的大体积混凝土结构相比,结构整体厚度更薄,温度分布更不均匀,升温和降温更快,更容易因存在较大温差而产生裂缝;实际工程中使用冷却水管降温后,内、外最大温差最大值为19.4℃,处于规范值25℃以下,相对无冷却水管的理论值降低了4.29℃,证明铺设冷却水管系统能有效降低混凝土中心温度,缩小内、外温差从而防止温度裂缝产生。

The configuration of large volume high-strength concrete hollow pier is complex,and there is limited research on the concrete hydration heat law.Taking the main bridge tower construction of Maanshan Highway-railway Yangtze River Bridge as a background,the finite element software Midas/Civil was used to establish the model and analyze the internal temperature field distribution of such high-strength concrete hollow pier column structures.Combined with measured data,the role of the cooling water pipe system was analyzed.The research results show that compared with the mass concrete structure with conventional shape,the temperature distribution of large volume high-strength concrete hollow pier,which has thinner overall thickness,is more uneven with faster warming and cooling,resulting in temperature cracks due to large temperature difference.The maximum temperature difference between inside and outside of the actual project after using the cooling water pipes for cooling is 19.4℃,which is below the standard value of 25℃,and is 4.29℃lower than the theoretical value without cooling water pipes.The results prove that the using of cold pipe system can effectively reduce the center temperature of concrete,reduce the temperature difference between inside and outside,so as to prevent the generation of temperature cracks.