scholarly journals Synergistic Bond Properties of Different Deformed Steel Fibers Embedded in Mortars Wet-Sieved from Self-Compacting SFRC

2021 ◽  
Vol 11 (21) ◽  
pp. 10144
Author(s):  
Xinxin Ding ◽  
Haibin Geng ◽  
Minglei Zhao ◽  
Zhen Chen ◽  
Jie Li
Keyword(s):  
Bearing Capacity ◽  
Cross Sections ◽  
Steel Fiber ◽  
Concrete Strength ◽  
Ultimate Bearing Capacity ◽  
Steel Fibers ◽  
Unit Weight ◽  
Bond Properties ◽  
Pull Out ◽  
Concrete Matrix

Reliable bond of steel fiber in concrete is a key problem relating to the reinforcing effect of steel fiber on concrete matrix and for the guide in significance for the optimal design of the geometry and mechanical properties of steel fiber. In this paper, on the basis of multi-indices of evaluation for the bond properties of single hooked-end steel fiber, the indices for the evaluation of synergistic bond properties of different deformed steel fibers are proposed. The pull-out tests were carried out for different deformed steel fibers embedded in mortar wet-sieved from self-compacting SFRC with manufactured sand. Fourteen types of steel fibers were used, including six hooked-end, two crimped, four indentation, one milling, and one large-end. The bond strength, bond energy, and bond toughness of single and per unit weight steel fiber were evaluated with the correspondence to the loading status of cracking resistance, normal serviceability, and ultimate bearing capacity of concrete. Results show that the deformed steel fibers presented different bond behaviors, hooked-end, and crimped steel fibers with circular cross-sections and a tensile strength of higher than 1150 MPa have excellent effects of strengthening, energy dissipation, and toughening capacity on self-compacting concrete with a cubic compressive strength of 60 MPa at normal serviceability and ultimate bearing capacity. Indentation, milling, and large-end steel fibers are more suitable for reinforcing the concrete strength due to the rigid bond before concrete cracking. The synergistic working of steel fibers with concrete matrix should be concerned to realize the effects of only or simultaneously reinforcing the strength and toughness of concrete.

Study on Bond Properties of Textile Reinforced Concrete

2013 ◽  
Vol 639-640 ◽  
pp. 334-340
Author(s):  
Wen Ling Tian ◽  
Li Min Zhang
Keyword(s):  
Reinforced Concrete ◽  
Epoxy Resin ◽  
Concrete Strength ◽  
Practical Method ◽  
Bond Properties ◽  
Textile Reinforced Concrete ◽  
Bond Behavior ◽  
Fine Grained ◽  
Pull Out ◽  
Concrete Matrix

Textile reinforced concrete (TRC) allows the light weight structures and offers a high effectiveness of the reinforcement by using continuous yarns. The study on the bond behavior between textile and concrete matrix is significant for the development of computational methods that analyze the textile reinforced concrete. The paper analyzes the bonding constitutive model of TRC and the bonding mechanism that the stress is transferred from fine concrete to textile, pointing out quadruple linear model can accurately reflect the bond behavior between fiber and concrete, illustrates the main influences on bond between the fine grained matrix and fabrics based on the pull-out test, the result reveals that with initial bond length increasing, the maximum pull force increases, and increasing concrete strength and improving workability of concrete matrix, epoxy resin impregnating and sand covering of textile as well as prestressing textile can increase the bond strength between textile and concrete. Finally the paper proposes that epoxy resin impregnating and 0.15 ~ 0.30mm sand covering of textile can be used as a practical method of improving bond properties in the engineering.

Analysis of Uniaxial Dynamic Performance of Concrete-Filled Square Steel Tube Composite Column

2011 ◽  
Vol 94-96 ◽  
pp. 220-224 ◽  
Author(s):  
Xi Guang Cui ◽  
Hai Dong Xu
Keyword(s):  
Strain Rate ◽  
Bearing Capacity ◽  
Dynamic Performance ◽  
Concrete Strength ◽  
Steel Tube ◽  
Ultimate Bearing Capacity ◽  
Element Analysis ◽  
Compression Performance ◽  
Calculation Results ◽  
Square Steel Tube

Considering the strain rate then puts forward the modified uniaxial dynamic constitutive model related to strain rate in concrete-filled square steel tube and the modified calculation results match well with the experimental results. Based on the above conclusion, uniaxial compression performance finite element analysis with different strain rate among 10-5/s–10-3/s is completed, the results showed that strain rate can obviously change the dynamic performance of the concrete-filled square steel tube. Through the analysis of the influencing factors of the core concrete compressive strength, it is showed that with the increasing of the strain rate and the improving of concrete strength, the ultimate bearing capacity of concrete-filled square steel tube is higher and the ductility is reduced. With the increasing of stirrup ratio, ultimate bearing capacity is greater and the ductility is enhanced. With the sectional dimensions increasing, the ultimate bearing capacity is greater and the ductility is enhanced.

Ultimate Bearing Capacity of Headed Studs in Tensile Concrete Slab

2010 ◽  
Vol 163-167 ◽  
pp. 11-15
Author(s):  
Wen Qi Hou ◽  
Mei Xin Ye ◽  
Ye Zhi Zhang
Keyword(s):  
Bearing Capacity ◽  
Concrete Slab ◽  
Concrete Strength ◽  
Influence Factors ◽  
Ultimate Bearing Capacity ◽  
Test Method ◽  
Test Results ◽  
Steel Girder ◽  
Push Out ◽  
Main Influence

Abstract. In the presented paper, reverse push-out test method was put forward and applied in the ultimate bearing capacity experiments of studs with concrete slab in tension. Ultimate bearing capacity experiments were carried out on 22 reverse push-out specimens composed of C50 or C40 concrete, 14MnNbq steel girder and Φ22studs. Results showed that ultimate bearing capacity of studs, pu, in tensile concrete slab is controlled by concrete failur, concrete strength, studs arragement and reinforcement ratio are the main influence factors of pu. Compared with that in compressive concrete, pu of Φ22 studs in tensile concrete is reduced about 30% averagely. According to the test results, a fitted load-slip relationship curve and a regression formula of pu for studs in tensile concrete were put forward, calculated results were in good agreement with the test results.

scholarly journals Investigation of the Match Relation between Steel Fiber and High-Strength Concrete Matrix in Reactive Powder Concrete

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1751 ◽  
Author(s):  
Guangyao Yang ◽  
Jiangxiong Wei ◽  
Qijun Yu ◽  
Haoliang Huang ◽  
Fangxian Li
Keyword(s):  
Compressive Strength ◽  
Steel Fiber ◽  
High Strength ◽  
Steel Fibers ◽  
Peak Strength ◽  
Reactive Powder Concrete ◽  
Medium Length ◽  
Reactive Powder ◽  
Concrete Matrix ◽  
Strength And Toughness

This study investigated the strength and toughness of reactive powder concrete (RPC) made with various steel fiber lengths and concrete strengths. The results indicated that among RPC samples with strength of 150 MPa, RPC reinforced with long steel fibers had the highest compressive strength, peak strength, and toughness. Among the RPC samples with strength of 270 MPa, RPC reinforced with short steel fibers had the highest compressive strength, and peak strength, while RPC reinforced with medium-length steel fibers had the highest toughness. As a result of the higher bond adhesion between fibers and ultra-high-strength RPC matrix, long steel fibers were more effective for the reinforcement of RPC with strength of 150 MPa, while short steel fibers were more effective for the reinforcement of RPC with strength of 270 MPa.

Anchorage Capacity of Headed Bars in Steel Fiber Reinforced Concrete

2021 ◽  
Author(s):  
Payal Sachdeva ◽  
A.B. Danie Roy ◽  
Naveen Kwatra
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Failure Modes ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Concrete Compressive Strength ◽  
Pull Out

Headed bars (HB) with different head shapes (Square, Circular, and Rectangular) and bar diameters (db: 16, 20, and 25 mm) embedded in steel fiber reinforced concrete have been subjected to pull-out test. The influence of head shapes, concrete compressive strength (M20 and M40), db, and steel fibers (0, 0.5, 1, and 1.5%) on the anchorage capacity of HB have been evaluated. Numerical model for improving the anchorage capacity of HB has also been proposed. Results have revealed that the anchorage capacity of HB increases with the increase in concrete compressive strength, db, and steel fibers, which have been validated by non-linear regression analysis using dummy variables. Two failure modes namely, steel and concrete-blowout have been observed and the prevailing mode of failure is steel failure. Based on load-deflection curves and derived descriptive equations, it is observed that the circular HB has displayed the highest peak load.

Numerical Simulation of the Fiber Pulled out from Steel-Fiber Concrete

2015 ◽  
Vol 723 ◽  
pp. 427-430
Author(s):  
Jun Liu
Keyword(s):  
Steel Fiber ◽  
Influencing Factor ◽  
Test Results ◽  
Element Analysis ◽  
Concrete Shrinkage ◽  
Pull Out ◽  
Fiber Concrete ◽  
Steel Fiber Concrete ◽  
Interface Contact ◽  
Concrete Matrix

ANSYS finite element analysis software is used to simulate the pull-out process of hooked-end steel fiber from concret in this paper. The contact element is adapted to simulate the interface contact of fiber and concrete, the effect of concrete matrix damage is ignored, the plastic deformation of fibers is considered and the numerical results is good compared with test results. In addition, the effect of some influencing factor on the pull-out process of fibers such as the interface friction coefficient, elastic modulus of matrix, the tensile strength of steel fiber and concrete shrinkage characteristics are discussed.

The Finite Element Analysis for Mechanical Properties of Reinforced FRP Pipe Concrete under Axial Compression - Discussing the Impact of Reinforcement Ratio, Concrete Strength

2013 ◽  
Vol 457-458 ◽  
pp. 1517-1522
Author(s):  
Wen Li ◽  
Hai Nan Yan ◽  
Peng Wang ◽  
Xiao Gang Chen ◽  
Li Na Yao
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Constitutive Relations ◽  
Concrete Strength ◽  
Ultimate Bearing Capacity ◽  
Reinforcement Ratio ◽  
Finite Element Software ◽  
The Impact

According to the basic idea of the finite element method, using the finite element software ANSYS to establish the finite element model of the reinforcement FRP pipe concrete under axial compression, introducing the unit selection in the process of building model ,based on the principle of meshing boundary conditions and constitutive relations selected; The significant degree of the model verified by compare with the test results. Analyzed by finite element reinforcement ratio, concrete strength and other factors on the mechanical properties of concrete under axial compression reinforcement FRP pipe, the analysis of the results shows: The increase of reinforcement ratio to improve the point load of the specimens and improve the composite column ultimate bearing capacity, but the reinforcement ratio increase will reduce the binding effect of the FRP pipe; The whole component be improved the strength of concrete can improve the ultimate bearing capacity, but it reduces the mechanical properties of the specimens.

scholarly journals Development of a New Inflatable Controlled Anchor System and Experimental Study of pull-out Capacity

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Xuexiang Yang ◽  
Shanpo Jia ◽  
Caoxuan Wen ◽  
Yuanjie Liu
Keyword(s):  
Bearing Capacity ◽  
Field Tests ◽  
Ultimate Bearing Capacity ◽  
Inflation Pressure ◽  
Working Mechanism ◽  
Anchor System ◽  
System A ◽  
Pull Out ◽  
New Type ◽  
Soil Interface

Considering the deficiency of traditional anchors, we propose a new type of inflatable controlled anchor system in this paper. The working mechanism and its structural composition of newly designed inflatable controlled device are discussed in detail. To investigate the performance and pull-out capacity of this new anchor system, a series of field tests were carried out under different inflation pressure conditions. By comparing these test results with those of traditional grouting anchors, a full-process constitutive model of anchor-soil interface is proposed to depict the pull-out characteristics of the inflatable controlled anchor. The results show that the ultimate bearing capacity of the inflatable controlled anchor is greater than that of the traditional grouting anchor when the inflation pressure is greater than 0.2 MPa and the ultimate bearing capacity of this new anchor improves obviously with the increase of inflation pressure. When the inflation pressure reaches 0.4 MPa, the ultimate bearing capacity of the inflatable controlled anchor is 2.08 times that of the traditional grouting anchor. Through comparison with the experimental curves, the results of model calculation indicate that the proposed anchor-soil interface constitutive equation can describe the pull-out characteristics of the inflatable controlled anchor. The designed controlled anchor has the advantages of no grouting, recyclability, rapid formation of anchoring force, and adjustable anchoring force.

Study on Bearing Capacity of Cylindraceous Double-Concrete Shaft Lining

2011 ◽  
Vol 368-373 ◽  
pp. 3022-3027
Author(s):  
Yan Long Ren
Keyword(s):  
Bearing Capacity ◽  
Concrete Strength ◽  
Strength Criterion ◽  
Failure Criteria ◽  
Ultimate Bearing Capacity ◽  
Design Strength ◽  
Elastic Module ◽  
Composite Shaft ◽  
Structure Specification ◽  
Shaft Lining

In this paper, elastic stress solution of cylindraceous double-concrete shaft lining was obtained by plane strain model. We derived the dimensionless formula of interface pressure of the double wall. So considering of that the concrete strength were largely improved under multiaxial compressed, we got the relationship between concrete strength increased coefficient of inner, outer shaft lining and geometry size, elastic-module, Poisson’s ratio of shaft lining by theoretical deriving, then the formulate of double-concrete shaft lining ultimate bearing capacity was proposed based on multiaxial strength criterion of concrete (G-W Failure Criteria) which advised by the existing design of concrete structure specification. All these provided a theoretical basis for rational calculating the ultimate bearing capacity of double-concrete composite shaft lining. The results were great significance for us to reduce the concrete design strength grade of shaft lining and project cost by using double-concrete composite shaft lining.

scholarly journals Prediction of Ultimate Bearing Capacity of Shallow Foundations on Cohesionless Soils: A Gaussian Process Regression Approach

2021 ◽  
Vol 11 (21) ◽  
pp. 10317
Author(s):  
Mahmood Ahmad ◽  
Feezan Ahmad ◽  
Piotr Wróblewski ◽  
Ramez A. Al-Mansob ◽  
Piotr Olczak ◽  
...  
Keyword(s):  
Gaussian Process ◽  
Bearing Capacity ◽  
Gaussian Process Regression ◽  
Ultimate Bearing Capacity ◽  
Shallow Foundations ◽  
Cohesionless Soil ◽  
Unit Weight ◽  
Cohesionless Soils ◽  
Computing Technique ◽  
Theoretical Approaches

This study examines the potential of the soft computing technique—namely, Gaussian process regression (GPR), to predict the ultimate bearing capacity (UBC) of cohesionless soils beneath shallow foundations. The inputs of the model are width of footing (B), depth of footing (D), footing geometry (L/B), unit weight of sand (γ), and internal friction angle (ϕ). The results of the present model were compared with those obtained by two theoretical approaches reported in the literature. The statistical evaluation of results shows that the presently applied paradigm is better than the theoretical approaches and is competing well for the prediction of UBC (qu). This study shows that the developed GPR is a robust model for the qu prediction of shallow foundations on cohesionless soil. Sensitivity analysis was also carried out to determine the effect of each input parameter.

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