Study On Flexural Capacity Of Stone Beams Strengthened By External Encased Steel Plate And Slates Strengthened By Reinforced Mortar

Stone as one of the earliest building materials,with its strength,durability has been widely used in the field of construction.China has a long history of stone structure construction,which is widely distributed in the coastal areas of southeastern Fujian and forms a unique residential culture,they still play an important role today.However,because the stone is a kind of brittle material,its tensile resistance is far less than the compressive capacity.Using stone to be main bending members such as beams and slates,in fact,there is a big security risk.Therefore,the reinforcement of the stone structure is particularly important.In order to ensure that the test process simulated in this paper can best meet the actual load of the flexural members,the stone used is removed from residential houses in the southeastern Fujian Province.After necessary cleaning,the reinforcement projects are undertaken by professional reinforcement workers.Combining research results at home and abroad,this article made relevant research:(1)Stone slabs were strengthened by reinforced mortar in order to study their reinforcement effect,and a practical calculation formula for flexural bearing capacity was deduced.Five slabs were reinforced and one slab was not reinforced as a control specimen.The effects of different reinforcement positions,mortar,and reinforcement ratios on the reinforcement effect of the flexural capacity of stone slab specimens were investigated.The results show that:before the cracking of the stone slab specimens,it basically meets the flat section assumption;this reinforcement method can effectively improve the flexural bearing capacity of the slab specimens,and the extent of reinforcement is influenced by the reinforcement ratio;the polymer mortar and the high reinforcement ratio are beneficial to improve their ductility;the anchorage hooks do not cause serious stress concentration on the slate,and have no effect on the flexural strength of the specimens;Before cracking,reinforced steel was all at low stress levels,and the tensile force of the components was basically borne by the stone,after cracking it was mainly borne by rebar.Based on the test results,reasonable assumptions are put forward,and the calculation formula for the flexural bearing capacity of the proj ect was derived.(2)A generic finite element analysis software called ABAQUS was used to simulate the slippage of the interface between the slate and mortar.The simulation results show that the yield of tensile steel bars in the mid-span of the specimen is the main cause of the sharp increase in the interface slip value;the interface slip after the cracking of the specimen is not uniformly increased,and the maximum slip value appears in the pure bend near the loading point,while the minimum slip value appears at the end of the specimen;the hoop reinforcement method can effectively reduce the slip damage value.(3)Stone beams were strengthened by external encased steel plate in order to study their reinforcement effect,and a practical calculation formula for flexural bearing capacity was deduced.Three stone beams were reinforced,and one stone beam was not reinforced as a control specimen.Explore the influence of different steel arrangement positions and steel ratios on the reinforcement effect of the flexural capacity of stone beam specimens.The results show that:before the cracking of the stone beam specimen,it basically meets the flat section assumption;this reinforcement method can effectively improve the flexural bearing capacity of the cross-section of the stone beam specimen,and the extent of improvement is greatly affected by the ratio of steel distribution;high steel rate is favorable to improve ductility of stone beam specimens;the reinforcement steel at the bottom of the cracking beam is at a low stress level;the tensile force of the components is basically borne by the stone;after cracking,the steel is mainly carried by the steel.Combining with the test results,reasonable assumptions were put forward,and the calculation formula for the flexural capacity of the girder bearing the test results and applicable to the actual project was deduced.