scholarly journals STUDY ON DETERIORATION STATE AND DECREASING IN THE PUNCHING SHEAR LOAD-CARRYING CAPACITY OF RC SLAB UNDER THE SALT・FROST DAMAGES AND THE STRESS-HYSTERESIS BY RUNNING VIBRATION LOADS

2009 ◽  
Vol 63 (1) ◽  
pp. 478-485
Author(s):  
Kazuhiko MINAKUCHI ◽  
Tadashi ABE ◽  
Tetsukazu KIDA ◽  
Junichiro OTAKE
2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Rajinder Ghai ◽  
Prem Pal Bansal ◽  
Maneek Kumar

There is a common phenomenon of shear failure in RCC beams, especially in old buildings and bridges. Any possible strengthening of such beams is needed to be explored that could strengthen and make them fit for serviceable conditions. The present research has been made to determine the performance of predamaged beams strengthened with three-layered wire mesh polymer-modified ferrocement (PMF) with 15% styrene-butadiene-rubber latex (SBR) polymer. Forty-eight shear-designed and shear-deficient real-size beams were used in this experimental work. Ultimate shear load-carrying capacity of control beams was found at two different shear-span (a/d) ratios 1 and 3. The sets of remaining beams were loaded with different predetermined damage levels of 45%, 75%, and 95% of the ultimate load values and then strengthened with 20 mm thick PMF. The strengthened beams were then again tested for ultimate load-carrying capacity by conducting the shear load test at a/d = 1 and 3. As a result, the PMF-strengthened beams showed restoration and enhancement of ultimate shear load-carrying capacity by 5.90% to 12.03%. The ductility of strengthened beams was improved, and hence, the corresponding deflections were prolonged. On the other hand, the cracking pattern of PMF-strengthened beams was also improved remarkably.


2020 ◽  
Vol 20 (08) ◽  
pp. 2050094
Author(s):  
Wanxiang Chen ◽  
Lisheng Luo ◽  
Zhikun Guo ◽  
Yingjie Wang

Fully clamped reinforced concrete (RC) slab is a common structural component possessing better load-carrying capacity over simply supported slab. Currently, typical yield line theory is a popular approach to estimate the bearing capacity of fully clamped RC slab, although it would greatly underestimate the actual ultimate resistance. This paper is devoted to enriching the knowledge of membrane action and its contribution to the load-carrying capacity of the clamped slab. The resistance trajectory of fully clamped RC slab from loading to failure undergoes three phases: the ascending branch raised by outward movement prevention, the descending branch due to crushed concrete and the re-ascending branch caused by reinforcement strain. Applied load–deflection curves of RC slab accompanying compressive-membrane actions are achieved according to the bending theory of normal cross-section. The reserve capacities accompanying tensile-membrane actions in the condition of large deformations are further derived. The whole load–deflection curves that considered compressive-tensile membrane effects are finally presented, where the mid-span displacements are revised by the deflection equations and the softening coefficient of flexural rigidity. It is indicated that the load–deflection relationships of fully clamped RC slabs can be reasonably depicted by taking compressive-tensile membrane effects into account, which are fairly different from yield line approaches. Comparative analysis shows that analytical results are in good agreement with experimental data reported by Park et al. and illustrates that the proposed model is capable of predicting the bearing capacity of fully clamped RC slab with very good accuracy.


2006 ◽  
Vol 62 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Tadashi ABE ◽  
Tetsukazu KIDA ◽  
Masaaki HOSHINO ◽  
Kiyoshi KATO ◽  
Ming-Chien HSU

Glass fibre reinforcement polymers (GFRP) application for reinforcement of wood, concrete and steel member is relatively becoming more variety in construction applications. Although it is possible to build large monolithic structures with composite materials, there are still several reasons for the structure to fail. One of the main reasons that contribute to this failure is the connection performance due to its function in carrying load across the structure. Thus having the right fundamental data for connection design purposes according to the specific and technological upgraded materials is very important. One of the basic methodologies in gaining the design data is through experimental double shear test which can be verified by European Yield Model (EYM) theory. Therefore, the objective of this research is to determine the load carrying capacity of double shear strength behaviour connections made of Kempas timber species as the main member and dowelled by the GFRP or the Kempas rod. The specimens were tested under the shear load with 2mm/min rate and tested until failure. From the experiment, it was found that the average ultimate shear strength of member dowelled with GFRP rod is 21.36% higher compared to one doweled with Kempas rod. According to mode of failure between two types of bolt, GFRP dowelled performs well (Mode I& IV) rather than Kempas dowelled (Mode IV).


2013 ◽  
Vol 753-755 ◽  
pp. 520-524
Author(s):  
Xin Zhao

Taking a flyover as the background, this paper compares two reinforcement scheme, and ultimately chooses the paste carbon fiber polymer method to reinforce the bridge. It calculates and analyzes the structure before and after the reinforcement, then compares the stress state , shear load-carrying capacity and flexural capacity. At last ,it evaluates the effect of the paste carbon fiber polymer method and puts forward some suggestions.


2021 ◽  
Vol 7 (7) ◽  
pp. 1244-1263
Author(s):  
R. Shivashankar ◽  
S. Anaswara

In the present paper, the interference effects on bearing capacity of two and three closely spaced strip footings resting on granular bed overlying clay are being studied. A simple analytical model is proposed to predict the load-carrying capacity and the interference factor of an interfered footing, when adjacent strip footings are optimally placed on the surface of a Granular Bed (GB) overlying clay and both the footings are simultaneously loaded. A punching shear failure mechanism is envisaged in the analytical model. The load-carrying capacity of the footing is taken as the sum of total shearing resistances along the two vertical planes through the edges of the strip footing in the upper granular layer and the load-carrying capacity of the soft clay beneath the GB. Insights gained from finite element simulations are used to develop the new modified punching shear model for interfering footing. Bearing capacity can be easily calculated by using the proposed punching shear model for interfering footing. The analytical model is validated with numerical analyses and previous experimental results and found to be in reasonably good agreement. The influence of different parameters such as granular bed thickness, width of footing, number of footings are carried out in this study. Doi: 10.28991/cej-2021-03091723 Full Text: PDF


2012 ◽  
Vol 18 (31) ◽  
pp. 214-221
Author(s):  
Takeshi Miyashita ◽  
Yusuke Okuyama ◽  
Dai Wakabayashi ◽  
Norio Koide ◽  
Yuya Hidekuma ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document