Research On The Mechanical Properties Of Carbon Textile Reinforced Concrete Thin Plates

Textile reinforced concrete(TRC)is a new type of cement-based composite materials which combines fine-grained concrete and high-performance textiles.TRC exhibits beneficial mechanical properties characterized with high load bearing capacity and relative strain hardening capacity as well as excellent durability.It is widely believed that TRC has great potential for development,and nowadays the promotion and application of TRC components are still in the basic research stage.An in-depth understanding of the fundamental mechanism developed via experimental investigation is necessary for analysis,modeling,and design.Therefore,the uniaxial tensile tests,four point and three point bending tests of TRC plates were carried out to discuss the effects of reinforcement ratio,steel fibres and prestress on the strength,deformation,crack pattern and failure behavior of TRC in this paper.The principle researches are as follows:(1)The main conclusions of TRC plates’ uniaxial tensile tests are as follows:TRC plates without steel fibres showed that the efficiency of carbon fibers decreased with the increase of textile ratio.During the test,the textile layer and matrix layer were gradually separated and finally TRC plates caused debonding failure.Applying prestress force on the textile could increase the first-crack stress of the TRC plates.Adding steel fibres in TRC plates was helpful to improve the interfacial bond properties,thus both the tensile strength and ultimate strain of the plates were enhanced.Within the scope of the test,the improvements of mechanical behavior were prominent with increasing prestress degrees or steel fibres proportions.Compared with the results obtained for the reference TRC plates,the tensile strength increased by approximately 100%because of the addition of 2%by volume steel fibres.Applying prestress on the textile at the same time adding 1%steel fibres in plates could significantly improve the efficiency of carbon fibers;consequently,carbon fibers were completely broken when the plates damaged.(2)The main conclusions of TRC plates’ four point and three point bending tests are as follows:The stiffness after cracking and flexural strength of TRC increased with the increase of textile layers.The number of cracks in the TRC plates were also increased,showing a multi-cracking pattern,However,the specimens occured obviously stripping phenomenon in the interface of textile layer and substrate layer.The interfacial bond performance of TRC improved when short discrete steel fibres with volume fraction 1%were added into the matrix and the mesh of the textile.Further,the load bearing capacity,deformation capacity and flexural toughness of the plates were greatly improved.Increases in first-crack load and ultimate load were observed in all experiments with the addition of steel fibres or pretensioning on textiles.Within the scope of the test,the improvement of flexural mechanical behavior was more prominent along with the increase of steel fibres contents.Adding steel fibres by 1%volume in prestressed plates might significantly improve the interfacial bond performance between substrate and textiles as well as the crack pattern,thereby leading to the change of failure modes from debonding failure or shear failure accompanied with stripping to the bending failure under the perfect condition of interface.(3)The calculation formula of TRC plates’ cracking load was theoretically deduced,and the crack resistance of TRC plate was calculated and analyzed.The methods of calculating the bending capacity of TRC plates under different failure modes were given.The theoretical analyses were in good consistent with the experimental results.