The Research On The Effects Of Basalt Fiber On High-performance Concrete

With the innovation of modern building technology and the construction and development of urban highway,The demand for the performance index of concrete becomes higher and higher,which makes the research on the performance of reinforced concrete become the hot spot today.So people turn their attention to fiber concrete,which can effectively improve the brittleness of concrete and have the effect of toughening and cracking on concrete.Basalt fiber is a new type of natural compound reinforcement.Many technical indicators are superior to other fibers.Adding to concrete can improve the performance of concrete.High performance basalt fiber concrete is a kind of new composite material.It is a kind of low water-binder ratio and high durability obtained by adding basalt fiber,fly ash,silica fume and superplasticizer into concrete.High strength and high fluidity of concrete.Through a large number of mechanical tests and microanalysis,The main conclusions are as follows:(1)The effects of basalt fibers with a diameter of 15 um and different lengths of 12mm/ 18 mm / 24mm)on the properties and mechanical properties of high performance concrete(HPC)were studied under different volume fractions of 0.1 and 0.2 and 0.3.The results show that the mixing of fiber has a certain influence on the working performance of concrete mixture,the slump and fluidity of concrete are decreased,The mechanical strength of the concrete is increased with the amount of volume of the fiber,and the brittleness of the concrete decreases.(2)The influence of two kinds of fibers with the length of 12 mm ~ 18 mm on the impermeability and frost resistance of concrete under the condition of low content was studied.The results show that when the volume ratio of basalt fiber is 0.05% and 0.10%,the impermeability of fiber reinforced concrete is better than that of non-fiber reinforced concrete,and the frost resistance is improved.However,when the volume fraction of fiber is 0.15%,it has little effect on the impermeability of concrete.(3)According to the relationship between the three point bending force and thedisplacement,it can be seen that the fiber can effectively improve the ductility of concrete.From the microstructure point of view,appropriate amount of basalt fiber mixed into high performance concrete,can be evenly dispersed in the concrete matrix,and the fiber surface coated with a layer of calcium silicate gel can bond well with the cementitious material.The external load is borne by the cement base and the fiber.The fiber can not only transfer the stress,but also change the development direction of the crack,delay the destruction of concrete,and achieve the purpose of toughening and preventing the crack of the concrete.The microstructure and macroscopic mechanical properties of concrete can be improved.Thus,the effect of fiber reinforced cement base was achieved.