风电场基础大体积混凝土裂缝控制施工技术探微

Construction Technology of Crack Control of Mass Concrete in Wind Power Plant Foundation

大体积混凝土受自然环境及自身结构特征影响,长期使用后极易收缩、裂缝,为此对风电场基础大体积混凝土裂缝控制施工技术进行研究。通过调配混凝土原料比例,采用不同用量的粉煤灰、减水剂、氧化镁抗裂剂以及不同保温措施来提升混凝土的抗裂性能,并分别制备了三种不同添加剂含量的试验试件。结果表明,在水泥用量500 kg/m3、粉煤灰用量180 kg/m3、减水剂用量0.4%、氧化镁抗裂剂用量40 kg/m3配比下混凝土裂缝控制效果最优。可见降低水泥用量、适当使用粉煤灰并添加外加剂能极大程度控制混凝土裂缝出现。同时在浇筑模板上添加保温薄膜与保温草垫,能降低混凝土内外温差,降低混凝土出现裂缝的概率。

Influenced by the natural environment and the structural characteristics of concrete itself,mass concrete is prone to shrinkage and cracking after long-term use.Therefore,the crack control construction technology of mass concrete of wind farm foundation is studied.With the proportion of concrete raw materials adjusted by adding different amounts of fly ash,water reducing agent,magnesium oxide anti-cracking agent,and different insulation measures being used to improve the anti-cracking performance of concrete,and three kinds of test specimens were prepared respectively.The test results show that the best crack control effect of concrete is achieved with a cement dosage of 500 kg/m3,fly ash dosage of 180 kg/m3,water-reducing agent dosage of 0.4%,and magnesium oxide crackresistant agent dosage of 40 kg/m3.The occurrence of concrete cracks can be effectively controlled by reducing the cement content,properly using fly ash and adding admixtures.At the same time,adding thermal insulation film and thermal insulation straw mat on the pouring formwork can reduce the temperature difference between inside and outside of concrete and control the probability of concrete cracks.