Flexural And Shear Experiments Of Fully Fabricated UHPC Beams And Study On Seismic Performance Of Beam-column Joint

With the in-depth promotion of China’s low-carbon environmental policy and the people’s increasing demand for high-quality buildings,assembled concrete structures usher in a broad space for development.The assembled concrete structure has the advantages of fast construction,green environment,and high efficiency,but the current construction of assembled concrete structure still retains on-site wet work,and there is greater room for innovation and research for full y dry-connected assembled structures.Ultra-High-Performance Concrete(UHPC)has the advantages of high strength and durability.It has the disadvantage of unfavorable on-site wet work,which is perfectly suitable for fully dry-joined assembled structures.In this paper,an assembly system of bolted fully precast slotted spliced members is designed,and the flexural and shear performance of fully precast spliced slotted UHPC beams and the seismic performance of new fully assembled UHPC beam-column joints are also investigated as follows.(1)The structural performance and construction scheme of the framing system based on fully prefabricated spliced slotted UHPC members were designed and detailed,and a lightweight and high-strength framing splicing system without on-site wet work was proposed.Five new connection structures were designed,which are mainly assembled by bolting.(2)Designed and completed the experimental study on the flexural and shear performance of fully prefabricated spliced slotted UHPC beams.The flexural test of 3beams and the shear test of 9 reverse spliced slotted UHPC beams were completed,and the flexural and shear performance of the I-beam spliced UHPC beams were studied and analyzed in terms of cracking and braking loads,deform ation,and the distribution of steel strain cracks.The spliced beam has good integrity,and the bolt ribs hinder the development of cracks and redistribute the internal force of the section.The shear resistance design of the beam,according to the curren t design code,has greater safety.(3)The low circumferential reciprocal load tests of one cast-in-place beamcolumn joint test member and three fully assembled beam-column joint test members were carried out.By compiling and studying the test results of the four test members,the seismic performance of the test members was studied and analyzed in terms of hysteresis curve,strength degradation.The test results show that the calculated values of ultimate bearing capacity of XJ test members are similar to the test values with an error of 4.97%,and the seismic performance is great;the assembly scheme of PC test members is feasible,but the design of joint stiffness needs to be further improved.