基于膨胀加强带超长超宽混凝土结构裂缝控制技术探究

TECHNOLOGY EXPLORATION ON CONTROLLING OF CRACKS IN SUPER LONG AND SUPER WIDE CONCRETE STRUCTURE BASED ON EXPANSION STRENGTHENING BAND

超长超宽大体积混凝土散热条件差,温度应力超过抗拉能力会引起温度裂缝。因此,释放混凝土浇筑体早期的收缩应力,控制混凝土水化热引起的里表温差及温升峰值等温控指标,避免浇筑体出现结构裂缝,是保证大体积混凝土施工质量的关键。以北京某医院新建病房楼工程为例,从原材料控制、采用膨胀加强带、科学掺加氧化镁、施工过程质量控制等方面较好地控制了混凝土裂缝,可为类似工程提供参考。

Cracks may be formed in super long and super wide concrete structure due to poor heat dissipation. Presence of cracks may be prevented by releasing the shrinkage stress of concrete pouring body at early stage and controlling the difference in temperature resulting from hydration heat of concrete and the peak temperature. This is critical to ensure the construction quality of bulk concrete. Taking the construction of a new building of a hospital as an example, cracks were prevented by controlling of raw materials, application of expansion reinforcing strip, addition of magnesium oxide and quality control of construction. It may serve as reference to similar construction.