Study On The Mechanical Properties Of TRC Assembled Permanent Formwork And Cast-in-Place Concrete Composite Column

Most of the formworks with a large amount of use each year are traditional formworks,including wood formworks,steel formworks,and glued formworks,which make the country consume a lot of resources such as wood and steel every year.Wasted glued formworks are also harmful to China's green ecology.Causes greater damage.Textile Reinforced Concrete(TRC)is a new type of high-performance cement-based composite material with high strength,corrosion resistance and strong plasticity.After construction,the TRC permanent formwork is combined with the cast-in-place concrete into a solid whole,which improves the structural performance and thus the mechanical properties of all aspects of the component.At present,some work has been done on the research of TRC permanent formwork,but the mechanical properties of TRC assembled permanent formwork need further study.Therefore,this paper analyzes the interface bond performance of TRC permanent formwork cast-in-place concrete under different bond length.On this basis,the mechanical properties of TRC assembled permanent formwork composite columns are analyzed by axial compression test.The specific research results are as follows:(1)The results show that when the bonding length of TRC permanent formwork is small,the debonding occurs in the matrix.When the length of TRC permanent formwork is long,the bond strength between the textile and the matrix is greater than the tensile strength of the textile,the textile breaks.In addition,when the bond length of TRC permanent formwork is greater than 150 mm,the interface bond force will not continue to increase with the increase of the formwork length,and the effective bond length of the formwork is considered to be about 150 mm.(2)Compared with plain concrete columns,the composite columns of TRC permanent formwork and cast-in-place concrete have better mechanical properties,show better crack control performance and improve crack development mode.For the stacked columns with different forms of TRC permanent formwork,the ultimate bearing capacity of the stacked columns formed with flat TRC permanent formwork is higher than that of L-shaped formwork.(3)The ultimate bearing capacity of the composite columns of TRC permanent formwork with different assembling methods is the largest when the bolts are combined with high-strength expansion grouting materials.In the flat TRC permanent formwork assembly method,compared with the use of high-strength expansion grouting and epoxy mortar,the compressive bearing capacity is highest when bolted.In the L-shaped TRC permanent formwork assembly method,compared with the use of high-strength expansion grouting and bolt connection,the method of using epoxy mortar has the highest compressive bearing capacity.(4)For TRC permanent formwork stacking columns with different assembly directions,the bearing capacity of the TRC formwork composite columns assembled only in the lateral direction is higher than that of the assembly composite columns in both directions.When assembled in two directions,the bolted connection exhibits better mechanical properties than the epoxy resin mortar.(5)By analyzing the bearing mechanism of the TRC permanent formwork laminated column,the calculation model of the TRC permanent formwork composite column bearing capacity is given,and the experimental value is compared with the theoretical value to verify the accuracy of the calculation model.The paper has 49 figures,10 tables,and 124 references.