橡胶混凝土梁裂缝分形理论分析

Study of Cracks on Rubber Concrete Beams Based on Fractal Theory

通过实验研究橡胶混凝土梁和普通梁在集中荷载下受弯性能,探讨橡胶粉对混凝土梁的承载力、裂缝宽度的影响。实验结果表明:两种梁表面裂缝分布都具有统汁意义上的自相似性;在同一荷载等级下橡胶混凝土梁的最大裂缝宽度小于普通混凝土最大裂缝宽度,胶粉的加入改善混凝土材料抗裂性能;利用分形理论求出各荷载等级下表面裂缝分维值,并建立起表面裂缝分维值与最大裂缝宽度间关系。

The flexural performances of a rubber concrete beam and a ordinary concrete beam are studied under concentrated load through the experiment.The influences of the content of the rubber powder in the rubber concrete beam on the bearing capacity and the crack width of beams are analyzed.The experimental results show that the crack distributions on two beam surfaces possess the characteristics of self-similar in statistical sense.The maximum crack width of the rubber concrete beam is less than that of the ordinary concrete beam under the same load level.The performance of anti-crack of the concrete beam is improved by adding the crumb rubber.Using the fractal theory,the fractal dimension values of the surface crack of the beams under different load grades are calculated and the relationship between the fractal dimension and the maximum crack width of the surface cracks is established.