An experimental study is conducted on fully grouted reinforced masonry shear walls (RMSWs) made from concrete blocks with a new configuration. Ten RMSWs are tested under reversed cyclic lateral load to investigate the...An experimental study is conducted on fully grouted reinforced masonry shear walls (RMSWs) made from concrete blocks with a new configuration. Ten RMSWs are tested under reversed cyclic lateral load to investigate the influence of different reinforcements and applied axial stress values on their seismic behavior. The results show that flexural strength increases with the applied axial stress, and shear strength dominated by diagonal cracking increases with both the amount of horizontal reinforcement and applied axial stress. Yield displacement, ductility, and energy dissipation capability can be improved substantially by increasing the amount of horizontal reinforcement. The critical parameters for the walls are derived from the experiment: displacement ductility values corresponding to 15% strength degradation of the walls reach up to 2.6 and 4.5 in the shear and flexure failure modes, respectively; stiffness values of flexure- and shear-dominated walls rapidly degrade to 17%–19% and 48%–57% of initial stiffness at 0.50 D<sub>max</sub> (displacement at peak load). The experiment suggests that RMSWs could be assigned a higher damping ratio (～14%) for collapse prevention design and a lower damping value (～7%) for a fully operational limit state or serviceability limit state.展开更多
The work presents the results of tests on the shear parameters of walls made of AAC （autoclaved aerated concrete, fb = 4.0 N/mm2） on the system mortar for thin M5 and M10 joints （fm = 6.1 N/mm2 and fro = 11.9 N/mm2...The work presents the results of tests on the shear parameters of walls made of AAC （autoclaved aerated concrete, fb = 4.0 N/mm2） on the system mortar for thin M5 and M10 joints （fm = 6.1 N/mm2 and fro = 11.9 N/mm2） and on polyurethane glue and also walls without mortar （dry masonry）. The wall compression strength （on mortar M5 class） （per EN 1052-1：2000） amounted tofc,mv= 2.97 N/mm2 （fk = 2.48 N/mm2）, elastic modulus was Ecru = 2,040 N/mm2. Various structure of bed joints and head joints were applied and the following were used as reinforcement： steel trusses of EFZ 140/Z 140 type （Z1 type） and meshes made of plastics （Z2 type）. Based on the tests carried out with regard to unreinforced elements, it was shown that the filling in of head joints with mortar had an advantageous effect on the values of cracking and destruction stresses. While, with the use of reinforcement, advantageous increase of stress was obtained only when the mortar was laid twice on both bed surfaces of masonry units. The application of reinforcement in the bed joints when the mortar was laid only on one bed joints surface of the masonry units reduced the values of cracking and destruction stresses in relation to the values obtained in the unreinforced walls.展开更多
基金National Technology Support Project under Grant No.2013BAJ12B03Heilongjiang Province Construction Group Ltd. United Research Program under Grant No.MH20100436
文摘An experimental study is conducted on fully grouted reinforced masonry shear walls (RMSWs) made from concrete blocks with a new configuration. Ten RMSWs are tested under reversed cyclic lateral load to investigate the influence of different reinforcements and applied axial stress values on their seismic behavior. The results show that flexural strength increases with the applied axial stress, and shear strength dominated by diagonal cracking increases with both the amount of horizontal reinforcement and applied axial stress. Yield displacement, ductility, and energy dissipation capability can be improved substantially by increasing the amount of horizontal reinforcement. The critical parameters for the walls are derived from the experiment: displacement ductility values corresponding to 15% strength degradation of the walls reach up to 2.6 and 4.5 in the shear and flexure failure modes, respectively; stiffness values of flexure- and shear-dominated walls rapidly degrade to 17%–19% and 48%–57% of initial stiffness at 0.50 D<sub>max</sub> (displacement at peak load). The experiment suggests that RMSWs could be assigned a higher damping ratio (～14%) for collapse prevention design and a lower damping value (～7%) for a fully operational limit state or serviceability limit state.
文摘The work presents the results of tests on the shear parameters of walls made of AAC （autoclaved aerated concrete, fb = 4.0 N/mm2） on the system mortar for thin M5 and M10 joints （fm = 6.1 N/mm2 and fro = 11.9 N/mm2） and on polyurethane glue and also walls without mortar （dry masonry）. The wall compression strength （on mortar M5 class） （per EN 1052-1：2000） amounted tofc,mv= 2.97 N/mm2 （fk = 2.48 N/mm2）, elastic modulus was Ecru = 2,040 N/mm2. Various structure of bed joints and head joints were applied and the following were used as reinforcement： steel trusses of EFZ 140/Z 140 type （Z1 type） and meshes made of plastics （Z2 type）. Based on the tests carried out with regard to unreinforced elements, it was shown that the filling in of head joints with mortar had an advantageous effect on the values of cracking and destruction stresses. While, with the use of reinforcement, advantageous increase of stress was obtained only when the mortar was laid twice on both bed surfaces of masonry units. The application of reinforcement in the bed joints when the mortar was laid only on one bed joints surface of the masonry units reduced the values of cracking and destruction stresses in relation to the values obtained in the unreinforced walls.
