Seismic performance of timber-framed masonry structure strengthened with ultra-high ductile concrete

Abstract:

To investigate the feasibility of timber-framed masonry structure reinforced with ultra-high ductile concrete (UHDC) layer and explore the influence of UHDC layer on the seismic performance of timber-framed masonry structure, shaking table tests were performed on 1/2 scaled timber-framed masonry structure model under conditions of original un-strengthened structure and UHDC strengthened structure. The seismic properties of un-strengthened structure and UHDC strengthened structure including dynamic characteristics, failure modes, displacement response, torsional effect, and base shear were compared and discussed. Test results show that the un-strengthened structure could not meet the seismic fortification requirements of the current code under the selected table excitation, and it could only be used after seismic reinforcement. The UHDC layer significantly improved the stiffness and reduced the stiffness degradation of the structure, so as to effectively control the structural damage under large earthquake and improve the seismic performance of the structure. Under rare earthquake of 9 degree, the x-direction inter-story drift of UHDC layer strengthened structure was 3.96‰. The UHDC layer reduced the torsional effect of the structure caused by structural asymmetry. The seismic performance of UHDC layer strengthened structure was better than that of CFRP strengthened structure. The structure strengthened with UHDC layer could meet the requirements of 8 degree seismic fortification intensity as stipulated in GB 50011—2010, which preliminarily proved that UHDC was feasible to repair the earthquake damaged structure and strengthen the existing buildings.