钢纤维增强混凝土的制备及力学性能研究

Preparation and mechanical properties of steel fiber reinforced concrete

单一混凝土存在韧性差、易开裂等缺陷,为增强混凝土材料的应用性能,将钢纤维混入其中制成钢纤维增强混凝土是当前的主要解决措施。为验证该措施的有效性,采用表观密度法进行配合比设计,配制出单一混凝土试件和钢纤维增强混凝土试件,并以单一混凝土试件为对比试验组。分别采用SEM、XRD和万能试验机等研究了试件的断面形貌、元素组成和力学性能。在力学性能分析阶段,研究了不同荷载作用下、不同钢纤维掺量条件时,单一混凝土试件和钢纤维增强混凝土试件的力学性能指标。结果表明,钢纤维增强混凝土试件的结构均匀且连续,具有较大的比表面积,试件受力后可以增大内部钢纤维表面的摩擦;钢纤维增强混凝土试件中C含量明显升高,占比达44%,试件的强度等级增大;通过对抗压强度、抗折强度、劈裂抗拉强度、断裂韧性和弹性模量等方面的研究,可知钢纤维增强混凝土试件的整体力学性能明显优于单一混凝土试件,说明钢纤维能够有效增强混凝土性能,提高混凝土韧性,防止裂缝出现。

The single concrete has defects such as poor toughness and easy cracking.In order to enhance the application performance of concrete materials,the main solution is to mix steel fiber into concrete to make steel fiber reinforced concrete.In order to verified the effectiveness of this measure,the apparent density method was used to design the mix proportion,and the single concrete specimen and steel fiber reinforced concrete specimen were prepared,and the single concrete specimen was taken as the contrast test group.SEM,XRD and universal testing machine were used to study the cross-section morphology,element composition and mechanical properties of the specimens.In the stage of mechanical property analysis,the mechanical properties of single concrete specimens and steel fiber reinforced concrete specimens under different loads and different steel fiber contents were studied.The results showed that the structure of steel fiber reinforced concrete was uniform and continuous,and had a large specific surface area,the friction of steel fiber surface could be increased after the specimen was stressed.The content of C in steel fiber reinforced concrete increased significantly,accounting for 44%,and the strength grade of steel fiber reinforced concrete increased.Through the study of compressive strength,flexural strength,splitting tensile strength,fracture toughness and elastic modulus,it could be seen that the overall mechanical properties of steel fiber reinforced concrete specimens were obviously better than that of single concrete specimens,which showed that steel fiber could effectively enhance the performance of concrete,improved the toughness of concrete and prevented cracks.