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Guo J.-P.,Beijing University of Technology | Deng Z.-C.,Beijing University of Technology | Lin J.-S.,Beijing Hand and Hand Building Technology Development Co. | Lu H.-B.,Beijing Hand and Hand Building Technology Development Co.
Gongcheng Lixue/Engineering Mechanics | Year: 2014

An innovative concrete reinforcing technique of prestressed high strength steel wire (steel wire rope) mesh (PSWM) is presented. Approximate full-scale tests of 24 concrete circular columns strengthened with PSWM and 2 contrast columns were put forward to research the strengthening effects of main experimental parameters of the steel wire spacing and the prestressing level of steel wire under axial loading. The test results show that the peak stress and strain of the strengthened columns are 83% and 95% greater than those of the contrast columns. By raising the steel wire prestressing level, the reinforcing effect is improved; with steel wire spacing decreased, strengthening effect is greatly improved. The formula of peak stress & strain and 2 kinds of stress-strain full curve relationship models of the columns strengthened with PSWM were proposed. The calculated results agree well with the experimental ones and a theoretical support for related research. The presented technology is an attractive, nondestructive, and efficient reinforcement technology, worthy of popularization and application. Source


Guo J.-P.,Beijing University of Technology | Deng Z.-C.,Beijing University of Technology | Lu H.-B.,Beijing Hand and Hand Building Technology Development Co. | Lin J.-S.,Beijing Hand and Hand Building Technology Development Co.
Gongcheng Lixue/Engineering Mechanics | Year: 2014

Based on the experimental results of 16 reinforced concrete (RC) columns strengthened with prestressed high strength steel wire mesh (PSWM) and 2 comparative RC columns under cyclic loadings and constant axial loading, the research of the restoring force model of RC columns strengthened with PSWM was carried out. According to the relevant experimental research, the materials' stress-strain relationships were determined; the stress-strain relationship equations of the reinforced concrete confined and strengthened with PSWM under axial loading were established. Considering the axial force of secondary moment effect, the calculation method of skeleton curves of the strengthened RC columns was presented. The restoring force model was established with Clough hysteresis rules. The research demonstrates that: by choosing the suitable material constitutive relationships and assumptions, and based on the force balance equations and existing simple hysteresis rules, the skeleton and hysteresis curves that agree well with the experimental results can be obtained. The restoring force model is simple, applicable and can be used to design and construction of RC columns strengthened with PSWM. Source


Guo J.,Beijing University of Technology | Deng Z.,Beijing University of Technology | Lin J.,Beijing Hand and Hand Building Technology Development Co. | Lu H.,Beijing Hand and Hand Building Technology Development Co.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2014

Sixteen reinforced concrete (RC) circular columns strengthening with an innovative technique using prestressed high strength steel wire mesh (PSWM) with new tensioning and anchor system and two contrast columns were put forward to research the seismic strengthening effects of main experimental parameters being axial compressive ratio, steel wire spacing, prestressing level of steel wire under cyclic loading and constant axial load. Test results show that the yield load, ultimate load, ductility coefficient and cumulative dissipated energy of the high and low axial compressive ratio columns are 36%, 44%, 76%, 62% and 36%, 27%, 44%, 127% greater than those of the contrast columns respectively. With steel wire spacing decreased, seismic strengthening effect is greatly improved. The stiffness is increased and the stiffness degradation mitigated. The seismic strengthening effect of the reinforced columns with steel wire spacing of 30 mm did not change significantly with increasing of prestressing force level. The presented technology is an active, nondestructive, and efficient strengthening technique. Source


Guo J.,Beijing University of Technology | Deng Z.,Beijing University of Technology | Lin J.,Beijing Hand and Hand Building Technology Development Co. | Lu H.,Beijing Hand and Hand Building Technology Development Co.
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2012

The performance of reinforced concrete slabs strengthened with high strength steel wire mesh at different prestress levels of a new tension and anchor system is studied. Three slabs reinforced with high strength steel wire mesh at different prestress levels were tested and compared with one original reinforced concrete slab and one non-prestressed reinforcement slab. Test results show that the load-bearing capacity and the flexural stiffness of the slabs strengthened with prestressed steel wire mesh were greatly improved and the crack width was obviously reduced if compared with the original slab. Comparing with the non-prestressed reinforcement slab, the load-bearing capacity and the flexural stiffness of the slabs strengthened with prestressed steel wire mesh were increased, the cracking load was significantly increased, and crack width decreased. By raising the prestress level of steel wire mesh, the reinforcement effect and the efficiency of utilizing the steel wire strength was improved. The prestress loss of steel wire was analyzed, and formulas were proposed to predict the load-bearing capacity of reinforced concrete slabs strengthened with different prestress levels of steel wire mesh. The theoretical results agree well with the experimental ones, and can be used for theoretical analysis and design of prestressed steel wire mesh for strengthening concrete structures. The prestressed steel wire reinforcement technology is an effective reinforcement technique, because it can resolve the defects of strain lag, peeling of the strengthened layer and the low level of utilizing the strength of steel wire. Source


Deng Z.-C.,Beijing University of Technology | Li H.,Beijing University of Technology | Lin J.-S.,Beijing Hand and Hand Building Technology Development Co. | Lu H.-B.,Beijing Hand and Hand Building Technology Development Co. | Cao W.,Beijing University of Technology
Beijing Gongye Daxue Xuebao/Journal of Beijing University of Technology | Year: 2013

Experiments were conducted to investigate the flexural behaviors of eight simply-supported RC beams strengthened with carbon fiber sheets, steel stands, prestressed steel stands, and steel plate individually and two comparative beams. Base on the experimental results, the flexural properties, failure characteristics, and the effect of different rehabilitation methods are analyzed. The cracking load, yielding load, ultimate load, ductility, development of cracks, deflection and rigidity are discussed. Experimental results show that 1) Compared with un-strengthened beams, the cracking load of RC beams strengthened with four different methods mentioned above are improved by 27.8%, 59.7%, 94.4% and 73.6%, respectively; yielding load are improved by 12.4%, 26.1%,36.2% and 37.6%, respectively; ultimate load are improved by 23.6%, 21.0%, 31.1% and 19.6%, respectively; and ultimate deflection declines by 23.6%, 21.0%, 31.1% and 19.6%, respectively. 2) From the angle of the normal use, the strengthening effect of beams strengthened with prestressed steel stands is better than that of un-prestressed. 3) Steel stand can effectively improve the post-yielding stiffness of strengthened beams, while that of steel plate is not very effective. Source

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