锈蚀后钢纤维和钢纤维混凝土的力学性能

Mechanical Performances of Steel Fiber and Steel Fiber Reinforced Concrete after Corrosion

通过对剪切型、铣削型、切断型3种钢纤维和钢纤维混凝土的快速锈蚀试验,研究了锈蚀前后钢纤维的外观、弯折性能和抗拉强度的变化,以及钢纤维混凝土经过不同锈蚀时间后的抗压强度和抗拉强度的变化规律.结果表明:随锈蚀时间的增加,钢纤维的锈蚀程度逐渐增大,弯折性能和抗拉强度逐渐降低,钢纤维混凝土的抗压强度和抗拉强度随之减小.但是抗压强度和抗拉强度的变化规律有所不同,当锈蚀时间较短时,抗压强度变化不明显,在锈蚀时间超过60d以后,抗压强度显著降低.而抗拉强度随锈蚀时间的增加逐渐下降.锈蚀时间相同时,抗拉强度的降低幅度比抗压强度的降低幅度小.切断型钢纤维的抗锈蚀能力相对较好,剪切型和铣削型钢纤维的抗锈蚀能力相对较差.

Based on the accelerated corrosion test on three different types of steel fibers such as shear-cut,mill-cut,and cut-off steel fibers and the accelerated corrosion test on steel fiber reinforced concretes reinforced with each type of the above steel fibers,the variations in the appearances,bending properties and tensile strengths of the steel fibers after corrosion and variation laws of both compressive and tensile strengths of the steel fiber reinforced concretes after different corrosion duration were investigated.The results indicate that increasing corrosion duration will increase degree of corrosion for the three types of steel fibers,hence decrease the bending properties and the tensile strengths of steel fibers as well as decrease the compressive and tensile strengths of steel fiber reinforced concrete.But variation appears different in the compressive and tensile strengths of steel fiber reinforced concrete.The compressive strengths change slightly with time when corrosion duration is short but decline substantially when corrosion duration is over 60 days.The tensile strengths of steel fiber reinforced concrete decrease gradually when corrosion duration increases.Under the same corrosion duration,the reduction degrees of tensile strengths of steel fiber reinforced concrete are lower than that of corresponding compressive strengths.Among the three types of steel fibers,the cut-off steel fibers possess better corrosion resistance than that of the shear-cut and the mill-cut steel fibers.