Experimental Study On Bonding Properties Of Glass Textile And Carbon Textile Reinforced Concrete

Textile Reinforced Concrete(TRC),called Fabric Reinforced Cementitious Matrix Composite(FRCM)as well,is a new type of fiber reinforced material emerging in recent 20 years.It is formed by placing fiber textile into concrete as a reinforcing material.It has the advantages of high bearing capacity,light weight,high strength,good ductility,no magnetic interference,corrosion resistance and so on.The mechanical properties of TRC composites are not only related to the properties of the constituent materials,but also to the interfacial properties between the fiber reinforced materials and the concrete matrix.The role of the interface in the composite material is to combine the matrix and the reinforcement material to form a whole,and achieve a good stress transmission mechanism under the action of external force.The interface is often the weakest part of the component during the load-bearing process,and the stress at the interface is often more complicated,the failure of the component is often the earliest at the interface.The effect of reinforcement on matrix depends on the interfacial bond between them.Therefore,it is very important to study the bonding performance of textile reinforced concrete.In this paper,the primary objective of this research is summarized as follows:(1)The static tensile tests of carbon fiber bundles and glass fiber bundles at room temperature and after high temperature have been completed.The experimental results show that the failure modes of the two kinds of fiber bundles are all stage failure of the fiber under static tension,which is related to the difference of the structure and mechanical properties of the fiber roving inside the fiber bundles.The tensile mechanical properties of the two kinds of fiber bundles show obvious temperature correlation.(2)The effects of the embedded depth of fiber bundles(15 mm,20 mm,25 mm)and the surface modification of fiber fabrics(fiber textile coated with glue,bonded sand)on the bonding properties between fiber bundle and concrete matrix were studied by the pullout tests of glass fiber bundles and carbon fiber bundles at room temperature.The results show that the pullout stiffness,ultimate pullout force and pullout work of the two kinds of fiber bundles increase with the increase of the embedded depth of the fiber bundles(15-25 mm),while the equivalent bond strength decreases.For glass fiber bundles,surface gluing treatment can greatly improve thebonding performance between fiber bundles and matrix,especially after surface sticking with sand;for carbon fiber bundles,the effect of the gluing treatment on the bonding performance is not obvious,the interfacial bonding force between fiber bundles and matrix is relatively small,and the high strength advantage of carbon fiber bundles can not be fully exerted.After sticking sand treatment,the improvement of bonding properties is obvious,and the bite force between the surface sand particles and the matrix plays a key role.(3)The effects of temperature(100-500 °C)and surface modification of glass textile(fiber textile coated with glue,bonded sand)on the interfacial bonding properties between fiber bundle and concrete matrix were studied by the pullout tests of glass fiber bundles after high temperature.The experimental results show that compared with the bonding properties at room temperature,the temperature treatment will cause the decline of the bonding properties.In the case of 100,200 and 300 °C,the improvement effect of surface sticking sand and gluing on the bonding properties of pullout specimens decreases with the increase of temperature,but in general,the existence of epoxy resin coating has a great effect on the bonding properties.When the test temperature reaches 400 °C,the effect of gluing and adhering on bonding performance is not significant.When the test temperature reaches 500 °C,the bonding performance is weakened by gluing and adhering sand.In addition,the untreated specimens on the surface of glass fiber bundles are less affected by high temperature,and the decrease of bonding properties is smaller;due to the damage of epoxy resin layer on the surface of fiber bundles caused by high temperature,the glass fiber bundles coated with epoxy resin and bonded with sand are greatly affected by high temperature,and the bonding properties are greatly reduced.