混凝土工程灾害与钢纤维增强混凝土(SFRC)

Engineering Calamity of Concrete and Steel Fiber Reinforced Concrete

随着混凝土强度的提高 ,对混凝土结构的安全性要求也更加突出了 ,然而 ,就混凝土结构而言 ,一直受物理性与化学性两大病害困扰 ,这两大病害是造成混凝土结构工程灾害的主要原因。而裂缝则是混凝土工程所有病害中最主要的因素 ,它大约占了 70 %的比例。此外 ,由于普通混凝土的抗拉强度一般都很低 ,拉应变与弯曲应变也很小 ,因此 ,普通混凝土结构中脆性破坏经常发生。为了改善普通混凝土的物理力学性能 ,人们一直在寻找各种方法和技术 ,钢纤维混凝土 (SFRC)因此应运而生。近 30年来 ,由于 SFRC能显著改善混凝土的韧性 ,并可极大地提高混凝土的抗拉强度 ,SFRC目前被广泛应用于土木、水利、矿山、交通等诸多领域。本文对 SFRC的阻裂与增强机理进行了综合阐述 ,同时 ,对 SFRC在混凝土工程病害的修复中的应用进行了讨论 ,最后 ,给出了一些建议。

With the heightening of the strength of concrete,the demand for safety of concrete structures arises.However, there have always been physical and chemical maladies for concrete structures.These two classes of maladies are main factors of the engineering disaster of concrete.Crack is the primary factor in all of the maladies of concrete engineering.It approximately accounts for 70 per cent. Furthermore,the tension strength of plain concrete is generally very low, and the strains of tension and flexure are also very small.In consequence,brittle failures often occur in plain concrete structures.In order to improve the physical mechanics performance of plain concrete,people have tried all sorts of methods and technologies.Steel fiber reinforced concrete(SFRC) is this kind of product. In the past thirty years, SFRC has extensively been applied to civil engineering,hydraulic engineering,mining,traffic,and so on because it can notably improve the toughness of concrete and enhance the tension strength of concrete.In this paper the mechanism for the prevention of crack and for the reinforcement of SFRC is introduced.Then,the application of SFRC in the quick repairing of engineering malady of concrete is discussed.And finally,some suggests are given.