Carbon Fiber Reinforced Concrete as an Intrinsically Smart Concrete for Damage Assessment During Dynamic Loading

1994 ◽  
Vol 360 ◽  
Author(s):  
Pu-Woei Chen ◽  
D.D.L. Chung
Keyword(s):  
Carbon Fibers ◽  
Inelastic Deformation ◽  
Fiber Reinforced Concrete ◽  
Short Fibers ◽  
Conduction Path ◽  
Electrically Conducting ◽  
Pull Out ◽  
Deformation And Fracture ◽  
Short Carbon ◽  
Smart Concrete

AbstractConcrete containing short carbon fibers (0.2-0.5 vol.%) was found to be an intrinsically smart concrete that can sense elastic and inelastic deformation, and fracture. The signal provided is the change in electrical resistance, which is reversible for elastic deformation and irreversible for inelastic deformation and fracture. The presence of electrically conducting short fibers is necessary for the concrete to sense elastic or inelastic deformation, but the sensing of fracture does not require fibers. The fibers serve to bridge the cracks and provide a conduction path. The resistance increase is due to conducting fiber pull-out in the elastic regime, conducting fiber breakage in the inelastic regime, and crack propagation at fracture.

Generation of Three-Dimensional Microstructure Model for Discontinuously Reinforced Composite by Modified Random Sequential Absorption Method

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Jiming Zhou ◽  
Lehua Qi ◽  
Arun M. Gokhale
Keyword(s):  
Carbon Fibers ◽  
Matrix Composite ◽  
Mechanical Response ◽  
Short Fibers ◽  
Alloy Matrix ◽  
Rsa Algorithm ◽  
Reinforced Composite ◽  
Microstructural Model ◽  
Microstructure Model ◽  
Short Carbon

Computer simulation of mechanical behavior of discontinuously reinforced composites containing randomly oriented short-fibers/whiskers presents an attractive opportunity for reduction of the number of experiments and resources required for microstructure design of such advanced materials. It is desirable to perform such simulations using microstructure model that accounts for randomness in angular orientations and locations of the short fibers/whiskers. In this contribution, a methodology is presented for efficient simulation of the required microstructural model through modification of well-known random sequential adsorption (RSA) algorithm for microstructure simulation through its application to the microstructure of Mg–alloy matrix composite containing randomly oriented short carbon fibers. The modified RSA algorithm enhances accuracy and efficiency of the complex geometric details of the randomly oriented short-fiber reinforced composite microstructure. Simulated microstructural model of composite is implemented in abaqus to simulate the mechanical response of the Mg–matrix composite containing randomly oriented short carbon fibers. The generated complex microstructure model in abaqus code is sliced into thin slices for reducing computing resources. The simulated results from multiple sliced models were averaged to approximate the result for the full volume element. The simulated mechanical response by use of multiple sliced models is validated via comparison with the experimental data.

scholarly journals Experimental Investigation and Modelling of the Layered Concrete with Different Concentration of Short Fibers in the Layers

Fibers ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 76
Author(s):  
Vitalijs Lusis ◽  
Olga Kononova ◽  
Arturs Macanovskis ◽  
Rimvydas Stonys ◽  
Inga Lasenko ◽  
...  
Keyword(s):  
Experimental Data ◽  
Bearing Capacity ◽  
Fracture Process ◽  
Fiber Reinforced Concrete ◽  
Short Fibers ◽  
Steel Fiber Reinforced Concrete ◽  
Load Bearing Capacity ◽  
Fiber Concentration ◽  
Load Bearing ◽  
Pull Out

The use of steel fiber reinforced concrete (SFRC) in structures with high physical-mechanical characteristics allows engineers to reduce the weight and costs of the structures, to simplify the technology of their production, to reduce or completely eliminate the manual labor needed for reinforcement, at the same time increasing reliability and durability. Commonly accepted technology is exploiting randomly distributed in the concrete volume fibers with random each fiber orientation. In structural members subjected to bending, major loads are bearing fibers located close to outer member surfaces. The majority of fibers are slightly loaded. The aim of the present research is to create an SFRC construction with non-homogeneously distributed fibers. We prepared layered SFRC prismatic specimens. Each layer had different amount of short fibers. Specimens were tested by four point bending till the rupture. Material fracture process was modelled based on the single fiber pull-out test results. Modelling results were compared with the experimental curves for beams. Predictions generated by the model were validated by 4PBT of 100 × 100 × 400 mm prisms. Investigation had shown higher load-bearing capacity of layered concrete plates comparing with plate having homogeneously distributed the same amount of fibers. This mechanism is strongly dependent on fiber concentration. A high amount of fibers is leading to new failure mechanisms—pull-out of FRC blocks and decrease of load-bearing capacity. Fracture surface analysis was realized for broken prisms with the goal to analyze fracture process and to improve accuracy of the elaborated model. The general conclusion with regard to modelling results is that the agreement with experimental data is good, numeric modelling results successfully align with the experimental data. Modelling has indicated the existence of additional failure processes besides simple fiber pull-out, which could be expected when fiber concentration exceeds the critical value.

scholarly journals Preparation of Nano-SiO2/Carbon Fiber-Reinforced Concrete and Its Influence on the Performance of Oil Well Cement

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Yanming Li ◽  
Xiaoyang Guo ◽  
Junlan Yang ◽  
Ming Li
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Fiber Reinforced Concrete ◽  
Cement Stone ◽  
Oil Well ◽  
Fiber Reinforced ◽  
Pull Out ◽  
Oil Well Cement ◽  
Carbon Fiber Reinforced ◽  
Well Cement

In view of the oilfield well thin oil layer, small gap, and side drilling cementing after perforating and subsequent stimulation caused by the cement ring embrittlement (i.e., secondary channeling), the preparation of nano-SiO2/carbon fiber-reinforced body and its influence on the performance of oil well cement were studied to improve the cement stone and enhance its adaptability to oil well pressure in this study. Carbon fibers were treated by liquid phase oxidation and a coupling agent, and the “grafting to” was used to bond nano-SiO2 and carbon fibers. It was found that the mechanical properties of the enhanced cement stone are far better than those of the blank cement stone. The compressive strength and tensile strength of the enhanced oil well cement stone were increased by 25% and 26%, respectively, compared with those of the blank oil well cement sample; the modulus of elasticity was reduced by 29%. Finally, the enhancement mechanism of SiO2/carbon fiber reinforcement on cement stone was explored by infrared, scanning electron microscopy, and XRD patterns. The deflection effect, pull-out effect, and bridging effect of crack were obtained.

Morphology and properties of PA6 hybrid composites filled with short carbon fibers and organoclay

2016 ◽  
Vol 2 (3) ◽  
pp. 47-57 ◽  
Author(s):  
S.S. Pesetskii ◽  
S.P. Bogdanovich ◽  
V.V. Dubrovskii ◽  
T.M. Sodyleva ◽  
V.N. Aderikha ◽  
...  
Keyword(s):  
Carbon Fibers ◽  
Hybrid Composites ◽  
Short Carbon

scholarly journals Absorption and Strength Properties of Short Carbon Fiber Reinforced Mortar Composite

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 300
Author(s):  
Md. Safiuddin ◽  
George Abdel-Sayed ◽  
Nataliya Hearn
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Water Absorption ◽  
Carbon Fibers ◽  
Strength Properties ◽  
Fiber Content ◽  
Test Results ◽  
Air Content ◽  
Entrapped Air ◽  
Short Carbon

This paper presents the water absorption and strength properties of short carbon fiber reinforced mortar (CFRM) composite. Four CFRM composites with 1%, 2%, 3%, and 4% short pitch-based carbon fibers were produced in this study. Normal Portland cement mortar (NCPM) was also prepared for use as the control mortar. The freshly mixed mortar composites were tested for workability, wet density, and entrapped air content. In addition, the hardened mortar composites were examined for compressive strength, splitting tensile strength, flexural strength, and water absorption at the ages of 7 and 28 days. The effects of different carbon fiber contents on the tested properties were observed. Test results showed that the incorporation of carbon fibers decreased the workability and wet density, but increased the entrapped air content in mortar composite. Most interestingly, the compressive strength of CFRM composite increased up to 3% carbon fiber content and then it declined significantly for 4% fiber content, depending on the workability and compaction of the mortar. In contrast, the splitting tensile strength and flexural strength of the CFRM composite increased for all fiber contents due to the greater cracking resistance and improved bond strength of the carbon fibers in the mortar. The presence of short pitch-based carbon fibers significantly strengthened the mortar by bridging the microcracks, resisting the propagation of these minute cracks, and impeding the growth of macrocracks. Furthermore, the water absorption of CFRM composite decreased up to 3% carbon fiber content and then it increased substantially for 4% fiber content, depending on the entrapped air content of the mortar. The overall test results suggest that the mortar with 3% carbon fibers is the optimum CFRM composite based on the tested properties.

Growth mechanism and thermal behavior of electroless Cu plating on short carbon fibers

2021 ◽  
pp. 127294
Author(s):  
Yuan Ma ◽  
Lingjun Guo ◽  
Lehua Qi ◽  
Jia Sun ◽  
Jiancheng Wang ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Carbon Fibers ◽  
Growth Mechanism ◽  
Short Carbon

scholarly journals EFFECT OF SHORT FIBERS ORIENTATION ON MECHANICAL PROPERTIES OF COMPOSITE MATERIAL – FIBER REINFORCED CONCRETE

2017 ◽  
Vol 23 (8) ◽  
pp. 1091-1099 ◽  
Author(s):  
Vitalijs LUSIS ◽  
Andrejs KRASNIKOVS ◽  
Olga KONONOVA ◽  
Videvuds-Arijs LAPSA ◽  
Rimvydas STONYS ◽  
...  
Keyword(s):  
Fiber Reinforced Concrete ◽  
Fracture Mechanisms ◽  
Short Fibers ◽  
Structural Element ◽  
Fibre Concentration ◽  
Four Point Bending ◽  
Fibre Concrete ◽  
Simulation Results ◽  
Fibers Orientation ◽  
Short Steel Fibres

Traditional fiberconcrete structures have fibres in the mix oriented in all spatial directions, distributed in the struc­tural element volume homogenously, what not easy to obtain in practice. In many situations, structurally more effective is the insertion of fibres into the concrete structural element body by forming layers, with a predetermined fibre concentration and orientation in every layer. In the present investigation, layered fibre concrete is under investigation. Short steel fibres were at­tached to flexible warps with the necessary fibres concentration and orientation. Warps were placed into the prismatic mould separating them by concrete layers without fibres. Prisms were matured and tested under four-point bending. The bending-affected mechanical behaviour of cracked fibre concrete was simulated numerically by using a developed struc­tural model. Comparing the simulation results with experimental data, material micromechanical fracture mechanisms were analysed and evaluated.

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