Experimental investigation on the behaviour of reinforced concrete slabs strengthened with ultra-high performance concrete

2017 ◽  
Vol 155 ◽  
pp. 463-474 ◽  
Author(s):  
Hor Yin ◽  
Wee Teo ◽  
Kazutaka Shirai
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Rakesh Kancharla ◽  
Venkata Rao Maddumala ◽  
T. V. N. Prasanna ◽  
Lokaiah Pullagura ◽  
Ratna Raju Mukiri ◽  
...  

Present technology has been evaluated greatly over the past decades, where new particles are being designed and fabricated to fulfill specific needs. The field of nano- and micromaterials has prospered in many disciplines. It has been recently used in reinforced concrete in the production of high-strength, high-performance concrete. Microsilica (MS) and nanosilica (NS) particles have proven to be highly profitable to the concrete mix. Concrete has become denser with considerable improvement in their mechanical characteristics, particularly compressive strength. This proposed method includes a comparative study of the flexural bending behavior of conventional reinforced concrete (without MS or NS) slabs with other slabs. Each has various mixes of MS and NS particles incorporated into the concrete mix. The material content utilized in the slabs is kept constant by replacing a portion of the cement with an equivalent amount of either NS or MS particles or both. MS particles are altered from 0, 5, and 10% while NS particles are altered from 0, 0.5, and 1.0%. It cracks the widths and has higher final load-bearing capacity.


2021 ◽  
Vol 25 (Special) ◽  
pp. 4-115-4-126
Author(s):  
Liwaa Abd Alhussen ◽  
◽  
Layth A. Al-jaberi ◽  
Ra’id F. Abbas ◽  
◽  
...  

The reaction of column to flat slabs may cause what is known as “punching shear stresses” when the stress is normally concentrated within the perimeter around the loaded area. In general, the reinforced concrete slabs are not designed for any shear failure due to the sudden nature of this type of failure. Many solutions can be followed to overcome such issue like increasing the depth of slab and diameter of columns. Increasing the slab thickness may add extensive dead loads and can breaks the economy justifications of this structural member. On the other hand, increasing the diameter of any column may un accepted due to architectural purposes. The high performance concrete is such type of concrete that illustrate high levels of mechanical performance “structural behavior as a consequence” if compared with normal concrete. Due to that, the high performance concrete may give good alternative an exceeds the problem of punching as a result. The basic aim of this study is to propose a brief review regarding this field of research. However, this study is divided to three parts, the first is devoted to view a suitable background about the punching shear capacity of traditional concrete slabs. The second part is registered to view the past experience in reinforced concrete slabs punching capacity and have steel fibers while the second part is devoted to present the state of art concerning the punching shear of high performance concrete slabs.


Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4622
Author(s):  
Kevin Paolo V. Robles ◽  
Jurng-Jae Yee ◽  
Seong-Hoon Kee

The main objectives of this study are to evaluate the effect of geometrical constraints of plain concrete and reinforced concrete slabs on the Wenner four-point concrete electrical resistivity (ER) test through numerical and experimental investigation and to propose measurement recommendations for laboratory and field specimens. First, a series of numerical simulations was performed using a 3D finite element model to investigate the effects of geometrical constraints (the dimension of concrete slabs, the electrode spacing and configuration, and the distance of the electrode to the edges of concrete slabs) on ER measurements of concrete. Next, a reinforced concrete slab specimen (1500 mm (width) by 1500 mm (length) by 300 mm (thickness)) was used for experimental investigation and validation of the numerical simulation results. Based on the analytical and experimental results, it is concluded that measured ER values of regularly shaped concrete elements are strongly dependent on the distance-to-spacing ratio of ER probes (i.e., distance of the electrode in ER probes to the edges and/or the bottom of the concrete slabs normalized by the electrode spacing). For the plain concrete, it is inferred that the thickness of the concrete member should be at least three times the electrode spacing. In addition, the distance should be more than twice the electrode spacing to make the edge effect almost negligible. It is observed that the findings from the plain concrete are also valid for the reinforced concrete. However, for the reinforced concrete, the ER values are also affected by the presence of reinforcing steel and saturation of concrete, which could cause disruptions in ER measurements


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