短切玄武岩纤维对混凝土抗氯离子侵蚀性能的影响

INFLUENCE OF SHORT BASALT FIBER ON CHLORIDE ION CORROSION REISTANCE OF CONCRETE

为研究短切玄武岩纤维对氯盐冻融作用下混凝土抗氯离子侵蚀性能的影响,试验制备了五组不同玄武岩纤维掺量的混凝土。探讨了玄武岩纤维掺量对混凝土抗压强度、自由氯离子浓度及氯离子扩散系数的影响,并建立了氯离子扩散系数与纤维掺量之间的定量函数关系。研究表明:玄武岩纤维的掺入提高了混凝土的抗压强度,减弱了冻融循环对混凝土抗压强度的破坏。在玄武岩纤维掺量为1.2 kg·m^-3时,抗压强度提高最为明显。适量玄武岩纤维的掺入有利于降低混凝土中自由氯离子的浓度和氯离子的扩散系数,而大量玄武岩纤维掺入会造成纤维结团,造成混凝土前期自由氯离子增长较快。在短切玄武岩纤维的作用下,混凝土氯离子扩散系数与玄武岩纤维掺量之间有着较好的二次函数关系。

In order to study the influence of chopped basalt fiber on the corrosion resistance of concrete under the action of chloride salt freeze-thaw,five groups of concrete with different basalt fiber content were prepared in the experiment.The effects of basalt fiber content on concrete compressive strength,free chloride ion concentration and chloride ion diffusion coefficient were studied and analyzed,and a quantitative functional relationship model between chloride ion diffusion coefficient and fiber content was established.The results of the study show that the addition of basalt fiber improves the compressive strength of concrete and reduces the damage to the concrete compressive strength caused by freeze-thaw cycles.When the basalt fiber content is 1.2 kg·m^-3,the compressive strength is the most obvious.The appropriate amount of basalt fiber is beneficial to reduce the free chloride ion concentration and chloride ion diffusion coefficient in the concrete,and the large amount of basalt fiber will cause fiber agglomeration to form pores,resulting in rapid growth of free chloride ion in the early stage of concrete.Under the action of chopped basalt fiber,there is a good quadratic function relationship between the chloride ion diffusion coefficient of concrete and the content of basalt fiber.