Effect of fiber dosage on water permeability using a newly designed apparatus and crack monitoring of steel fiber–reinforced concrete under direct tensile loading

2021 ◽  
pp. 147592172110528
Author(s):  
Zahoor Hussain ◽  
Zhang Pu ◽  
Abasal Hussain ◽  
Shakeel Ahmed ◽  
Atta Ullah Shah ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Reinforced Concrete ◽  
Water Permeability ◽  
Laser Scanning ◽  
Steel Fiber ◽  
Tensile Loading ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Direct Tensile

Cracks in concrete structures have always been the main reason to allow the aggressive and harmful agents to infringe the concrete resulting in its deterioration and decreasing lifespan. In the present study, the water permeability of the cracked concrete has been investigated. The consequences of cracking on the durability and endurance of concrete were also studied. A state-of-the-art permeability setup was designed to measure the water flow in normal and fiber-reinforced concrete under direct tensile loading. The setup was convenient for determining the average stress applied to the concrete specimens and simultaneously the maximum crack opening. Furthermore, the effect of fiber content on the cracking geometry (tortuosity and roughness) was evaluated by incorporating the coordinate data of the cracked surface using a 3D sensor-based laser scanning data acquisition system. To understand the effect of fiber content on the cracking geometry (tortuosity and roughness), the acquired data were then analyzed. Test results show that the designed setup is suitable to measure the water permeability under direct tensile loading. Water permeability decreased upon increasing the steel fiber dosage. Besides, the results show that tortuosity decreased while surface roughness increased with the fiber dosage increment. Promising preliminary results indicated that there is an inverse relationship between surface roughness and water permeability. The crack sensing setup successfully monitored the crack.

Penetration Resistance Research of Fiber Reinforced RPC

2014 ◽  
Vol 1055 ◽  
pp. 23-26
Author(s):  
Can Xu
Keyword(s):  
Reinforced Concrete ◽  
Coarse Aggregate ◽  
Steel Fiber ◽  
Penetration Resistance ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Quartz Powder ◽  
Steel Fiber Reinforced Concrete

In the original to remove steel and steel fiber reinforced concrete coarse aggregate in quartz powder and a small amount of activator, can boost steel fiber content, and its application in construction makes it more convenient, but how the penetration resistance works is not particularly clear. Through the penetration resistance experiment, found that when joined the SF and BF, RPC can still keep complete even after three times by penetration ,indicating the good performance of penetration resistance.

Punching Shear Capacity of Steel Fiber Reinforced Concrete Slab- Column Connections

2019 ◽  
Author(s):  
Josef Landler ◽  
Oliver Fischer
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Fiber Type ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Punching Shear ◽  
Slab Thickness ◽  
Shear Reinforcement ◽  
Fiber Reinforced

<p>To design flat slabs directly supported on columns, the punching shear resistance of the slab is a main factor. It can be increased in the vicinity of the slab-column connection with punching shear reinforcement, like bent up bars or shear studs, to bear the high reaction forces. However, the usage of punching shear reinforcement requires the knowledge of special design rules and often leads to problems and deficiencies in construction.</p><p>Fiber reinforced concrete seems to be a promising alternative to conventional punching shear reinforcement. To investigate the load bearing behavior of the slab-column connection using fiber reinforced concrete, a total of eight punching shear tests were performed. The specimens were realized with a typical top and bottom flexural reinforcement, but without punching shear reinforcement. Varied parameters were the slab thickness with 250 mm and 300 mm and the fiber content V<sub>f</sub> with 0.5 Vol.-% and 1.0 Vol.-%. To investigate the influence of modern fiber types, normal- and high-strength steel fibers with normal- and double-hooked-ends were used.</p><p>In all eight experimental tests, the intended punching shear failure was achieved. The capable load using fiber reinforced concrete increased by 20 % to 50 % compared to the reference tests without steel fibers, depending on the fiber type and the fiber content V<sub>f</sub>. Additionally, this load increase was accompanied by a significant improvement in ductility. The post-cracking behavior was noticeably influenced by the used steel fiber type. An influence of the slab thickness or steel fiber type on the shear strength contributed by the fiber reinforced concrete could not be determined.</p>

Bending Tests of Full-Scale Steel Fiber-Reinforced Concrete Segments of Shield Tunnel

2018 ◽  
Vol 768 ◽  
pp. 326-330
Author(s):  
Bo Chen ◽  
Li Ping Guo ◽  
Wei Sun ◽  
Cong Ding
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Peak Load ◽  
Full Scale ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Shield Tunnel ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Bending Tests

To evaluate the bending performance of a steel fiber-reinforced concrete shield segment, bending testing was conducted on prism specimens and full-scale segments with 30 kg/m3and 40 kg/m3steel fiber. The results show that, with increasing fiber content, the ultimate and equivalent flexural strengths increase, while the flexural toughness of the prism concrete specimen increases by approximately 15%. With increasing fiber content, the flexural capacity of the shield tunnel segment increases, the peak load increases by 24%, the crack number increases, and the average crack width decreases. During bending tests, the steel fiber-reinforced concrete segment shows remarkable characteristics of strain hardening and multiple cracking. The embedded parts reduce the cross-sectional area and cause stress concentration in the mid-span; therefore, the main crack form in this region.

scholarly journals Experimental Investigation on Mechanical Behavior of Anchor and Shotcrete Support System Under Axial Pull-out Action

2021 ◽  
Author(s):  
Xiliang Liu ◽  
Feiyue Sun ◽  
Fuli Kong ◽  
Jiaqi GUO
Keyword(s):  
Reinforced Concrete ◽  
Mechanical Behavior ◽  
Support System ◽  
Steel Fiber ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Pull Out ◽  
Failure Properties

Abstract Based on axial pull-out performance tests of anchor and shotcrete support system with three types of plates and two kinds of shotcretes (plain and steel fiber reinforced concrete) conducted by use of the multi-functional testing system. The mechanical behavior of the anchor and shotcrete support system with the different plate and shotcrete such as the pull-out performance of support system, deformation and failure properties of shotcrete was studied and analyzed. Experimental results showed that the relationship curves between elongation and drawing force has three stages, which are elastic, yielding and strengthening. Different plate types have obvious influence on the tensile stiffness during the elastic stage. The steel fiber reinforced concrete spray layer can improve the yield strength of rockbolt under the coupling effect by the support system. The strain at the interface between the initial shotcrete layer and surrounding rock mass is greater than that of the external surface of the resprayed shotcrete layer, though they are equal far away from the rockbolt hole. The shotcrete strain values of steel fiber reinforced concrete is lower than that of plain concrete, and the shotcrete strain values decreases with the improvement of steel fiber content. For shotcrete strain values on the same position, the higher they are the steel fiber content, the lower their strain will be. The failure of plain shotcrete usually begins around of rockbolt hole, when the interfacial stress between the initial shotcrete layer and surround rock is higher than that in the initial shotcrete layer and resprayed shotcrete layer. The steel fiber can effectively improves the toughness, anti-cracking performance and prevent fracture of shotcrete from failure properties.

Sign in / Sign up

Export Citation Format

Share Document