大体积混凝土的有害裂缝的防治

混凝土有害裂缝控制是大体积混凝土施工成败的关键所在,本文通过介绍在裕龙大厦主楼承台筏板基础大体积混凝土的施工中,从控制混凝土的入模温度、混凝土的水化热升温、延缓降温速率、控制混凝土内外温差、减少混凝土收缩、提高混凝土极限抗拉伸强度、改善约束条件和设计构造等方面全面考虑,并通过混凝土裂缝控制理论计算,结合实际采取一系列保证措施,从而有效地控制筏板基础大体积混凝土有害裂缝的出现和发展,且内外温差均小于要求值,养护期满后强度达到设计要求,无开裂、渗漏现象.(英文摘要在吕老师处)(可缩减为)本文从降低水泥水化热、降低混凝土内外温度差、提高混凝土极限抗拉伸强度、改善约束条件等方面采取一系列保证措施,从而达到有效地控制底板大体积混凝土有害裂缝的出现.

The Prevention of Harmful Concrete Cracks

How to control the harmful concrete cracks is the key to construction for mass concrete.In this paper a series of control measures in the construction of the grade slab foundation for the cushion cap of Yulong Mansion main structure is presented,such as controlling the temperature where the concrete is put into the form,the heat of hydration and the internal-external temperature difference of concrete;but also staying the cooling rate,reducing the concrete shrinkage,improving the ultimate tensile strength,the constraint condition and the design structure.By doing these treatments the harmful concrete cracks are controlled well,and the internal-external temperature difference of concrete is less than allowable value,other than the concrete hardness meets design requirements,no cracking and leaking.