大掺量粉煤灰混凝土抗裂性能试验研究

Research on Crack Resistance of High Volume Fly Ash Concrete

混凝土的抗裂性是评价混凝土耐久性的重要指标,极限拉伸和干缩变形是影响混凝土抗裂的主要指标。粉煤灰因其优良的性能,在工程建设中得到了广泛的应用。结合实际工程,研究了掺量达到80%的粉煤灰混凝土的极限拉伸和干缩变形等性能,并且分析了粉煤灰的作用机理。结果表明:大掺量粉煤灰混凝土的干缩率随着粉煤灰掺量的增加而不断减小;随着粉煤灰掺量的增加,60 d龄期的抗拉强度和抗压强度均高于或趋近与基准混凝土;综合考虑极限拉伸和干缩变形等因素的影响,得出大掺量粉煤灰混凝土有利于提高混凝土的抗裂性能。

Evaluation of crack resistance of concrete is an important indicator of concrete durability. Ultimate tensile and drying shrinkage deformation are the main indicators of concrete cracking. Fly ash are widely used in project construction because of its excellent performance. Based on the actual project , this paper is an attempt to study ultimate tensile and shrinkage deformation and other properties of fly ash content concrete, analyze the mechanism of fly ash. The results show that： high volume fly ash concrete shrinkage rate increases with the increase in fly ash. With the increase in fly ash, 60 d age of the tensile strength and compressive strength higher or closer to the benchmark of concrete; comprehensive consideration of ultimate tensile and shrinkage deformation and other factors, high volume fly ash concrete can improve the crack resistance of concrete.