scholarly journals Mechanical Model for Punching Shear and Theoretical Load-Carrying Capacity of RC Slabs with UFC Panel

2011 ◽  
Vol 60 (10) ◽  
pp. 918-925
Author(s):  
Tadashi ABE ◽  
Satoshi SONOKI ◽  
Tetsukazu KIDA ◽  
Satoshi TANAKA
Keyword(s):  
Carrying Capacity ◽  
Mechanical Model ◽  
Punching Shear ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Rc Slabs

Flexural strengthening of pre-cracked RC slabs with prestressed NSM CFRP laminates and evaluation of strain loss

2021 ◽  
pp. 136943322110105
Author(s):  
M.R. Mostakhdemin Hosseini ◽  
Salvador J.E. Dias ◽  
Joaquim A.O. Barros
Keyword(s):  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Transfer Length ◽  
Rc Structures ◽  
Cracked Concrete ◽  
Flexural Strengthening ◽  
Cfrp Laminates ◽  
Load Carrying ◽  
Rc Slabs

The strengthening intervention of RC structures often involves already cracked concrete. To evaluate the effect of the level of damage prior to the strengthening (pre-cracks) on the behavior of the flexurally strengthened RC slabs with prestressed NSM CFRP laminates, an experimental research was carried out. Two pre-cracking levels of damage were analyzed and, for each one, three levels of prestress were tested (0%, 20% and 40%). The obtained results showed that the strengthening of damaged RC slabs with prestressed NSM CFRP laminates results in a significant increase on the load carrying capacity at serviceability limit states. Pre-cracked RC slabs strengthened with prestressed NSM CFRP laminates presented a load carrying capacity almost similar to the corresponding uncracked strengthened slabs. To determine the effective prestress level in CFRP laminates, the variation of strain over the length of the CFRP and over time was experimentally recorded. The prestress transfer length was also evaluated. The experimental results revealed that the transfer length of CFRP laminates was less than 150 mm, and the maximum value of strain loss out of transfer length (around 14%) was measured close to the cracked section of the damaged RC slabs. Significant part of strain loss in CFRP laminates occurred during 24 h after releasing the prestress load.

Load-Carrying Capacities of Fully Clamped RC Slab Accompanying Compressive-Tensile Membrane Actions: A Theoretical Approach

2020 ◽  
Vol 20 (08) ◽  
pp. 2050094
Author(s):  
Wanxiang Chen ◽  
Lisheng Luo ◽  
Zhikun Guo ◽  
Yingjie Wang
Keyword(s):  
Bearing Capacity ◽  
Carrying Capacity ◽  
Flexural Rigidity ◽  
Load Carrying Capacity ◽  
Membrane Action ◽  
Yield Line ◽  
Load Carrying ◽  
Membrane Effects ◽  
Rc Slab ◽  
Rc Slabs

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.

scholarly journals Bearing Capacity of Interfered Adjacent Strip Footings on Granular Bed Overlying Soft Clay: An Analytical Approach

2021 ◽  
Vol 7 (7) ◽  
pp. 1244-1263
Author(s):  
R. Shivashankar ◽  
S. Anaswara
Keyword(s):  
Bearing Capacity ◽  
Analytical Model ◽  
Carrying Capacity ◽  
Soft Clay ◽  
Punching Shear ◽  
Load Carrying Capacity ◽  
Granular Bed ◽  
Shear Model ◽  
Load Carrying ◽  
Strip Footings

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

Development of cost-effective PL-3 concrete bridge barrier reinforced with sand-coated glass fibre reinforced polymer (GFRP) bars: static load tests

2014 ◽  
Vol 41 (4) ◽  
pp. 368-379 ◽  
Author(s):  
H. Khederzadeh ◽  
K. Sennah
Keyword(s):  
Carrying Capacity ◽  
Shear Failure ◽  
Ultimate Load ◽  
Cost Effective ◽  
Punching Shear ◽  
Transverse Load ◽  
Load Carrying Capacity ◽  
Gfrp Bars ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity

One of the main factors concerning durability and service life of steel-reinforced bridges is corrosion of steel bars especially when exposed to a harsh environment. The use of glass fibre reinforcing polymer (GFRP) bars as non-corrosive material has emerged as an innovative solution to corrosion related problems, reduce the maintenance cost, and increase the service life of bridge structures. A recent cost-effective design of PL-3 bridge barrier was developed at Ryerson University incorporating high-modulus GFRP bars with headed ends. This paper presents results of full-scale static tests to collapse performed on the developed PL-3 bridge barrier at interior and exterior locations to investigate the ultimate load carrying capacity to be compared with Canadian Highway Bridge Design Code (CHBDC). The experimental ultimate load carrying capacity of the barriers was observed to be far greater than CHBDC factored design transverse load. The failure pattern was initiated by a trapezoidal crack pattern at the front face of the barrier, followed by punching shear failure at the transverse load location. Based on the punching shear failure developed in the barrier wall and comparison with available punching shear equations in the literature, an empirical punching shear equation is proposed to determine the transverse load carrying capacity of PL-3 bridge barrier walls reinforced with GFRP bars.

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