A Four Novel Energy Pattern Factor Method for Computation of Weibull Parameter in Impact Strength Reliability of Fibre-Reinforced Concrete

2018 ◽  
Vol 7 (3.12) ◽  
pp. 272
Author(s):  
Gayathri R ◽  
Murali. G ◽  
Parthiban Kathirvel ◽  
Haridharan M.K ◽  
Karthikeyan. K

Impact strength data is a noteworthy factor for designing airport pavements, civilian and military structures etc and it is ought to be modelled precisely. In order to achieve an appropriate modelling data, it is important to select a suitable estimation method. One such commonly used statistical tool is the two parameter Weibull distribution for modelling impact failure strength accurately besides the variations in test results. This study statistically commandsthe variations in the impact failure strength (number of blows to induce failure) of fibre reinforced concrete (FRC) subjected to drop hammer test. Subsequently, a four-different novel method for the computation of Weibull parameter (Shape parameter) based on the earlier researchers test results has been proposed. The accuracy of the proposed four novel method is demonstrated by comparing with power density method and verified with goodness of fit test. Finally, the impact failure strength of FRC is offered in terms of reliability. The proposed four NEPFM is very suitable and efficient to compute the shape parameter in impact failure strength applications. 

2018 ◽  
Vol 7 (3.12) ◽  
pp. 272
Author(s):  
Gayathri R ◽  
Murali. G ◽  
Parthiban Kathirvel ◽  
Haridharan M.K ◽  
Karthikeyan. K

Impact strength data is a noteworthy factor for designing airport pavements, civilian and military structures etc and it is ought to be modelled precisely. In order to achieve an appropriate modelling data, it is important to select a suitable estimation method. One such commonly used statistical tool is the two parameter Weibull distribution for modelling impact failure strength accurately besides the variations in test results. This study statistically commandsthe variations in the impact failure strength (number of blows to induce failure) of fibre reinforced concrete (FRC) subjected to drop hammer test. Subsequently, a four-different novel method for the computation of Weibull parameter (Shape parameter) based on the earlier researchers test results has been proposed. The accuracy of the proposed four novel method is demonstrated by comparing with power density method and verified with goodness of fit test. Finally, the impact failure strength of FRC is offered in terms of reliability. The proposed four NEPFM is very suitable and efficient to compute the shape parameter in impact failure strength applications. 


2019 ◽  
Vol 26 (4) ◽  
pp. 197-208
Author(s):  
Leo Gu Li ◽  
Albert Kwok Hung Kwan

Previous research studies have indicated that using fibres to improve crack resistance and applying expansive agent (EA) to compensate shrinkage are both effective methods to mitigate shrinkage cracking of concrete, and the additions of both fibres and EA can enhance the other performance attributes of concrete. In this study, an EA was added to fibre reinforced concrete (FRC) to produce concrete mixes with various water/binder (W/B) ratios, steel fibre (SF) contents and EA contents for testing of their workability and compressive properties. The test results showed that adding EA would slightly increase the superplasticiser (SP) demand and decrease the compressive strength, Young’s modulus and Poisson’s ratio, but significantly improve the toughness and specific toughness of the steel FRC produced. Such improvement in toughness may be attributed to the pre-stress of the concrete matrix and the confinement effect of the SFs due to the expansion of the concrete and the restraint of the SFs against such expansion.


2017 ◽  
Vol 23 (6) ◽  
pp. 806-813 ◽  
Author(s):  
Inmaculada MARTÍNEZ-PÉREZ ◽  
Juozas VALIVONIS ◽  
Remigijus ŠALNA ◽  
Alfonso COBO-ESCAMILLA

The building of structures from steel fibre reinforced concrete (SFRC) in the external and conventional rein­forced concrete (RC) in the internal layer represents an economical alternative of structures effectively using SFRC. The paper presents test results of flexural behaviour of layered beams with SFRC external layers and RC internal layer. The behaviour of these beams is compared to test results of SFRC and conventional RC beams. The test results show, that the flexural load capacity for all series of beams is nearly similar, but the deflections of layered beams are less comparing to monolithic ones. It also been shown that the equations indicated in the Eurocode 2 can be used to design the flexural reinforcement in layered SFRC beams.


1990 ◽  
Vol 211 ◽  
Author(s):  
P. Hamelin ◽  
M. Razani

AbstractThis research work concerns the impact behaviour of metallic fibre reinforced concrete. After a description of the experimental apparatus used, an air compressed gun, we present the main results in terms of stress–strain diagrams as a function of the strain rate. Then, we establish equations of a specific damage model which take account of the different phases of the behaviour law.


2000 ◽  
Vol 27 (4) ◽  
pp. 774-784 ◽  
Author(s):  
Benoît Bissonnette ◽  
Yves Therrien ◽  
Richard Pleau ◽  
Michel Pigeon ◽  
François Saucier

This paper presents the results of an investigation aimed at establishing if multiple cracking can be an intrinsic property of steel fibre reinforced concrete (SFRC) in the hardened state and identifying the conditions to obtain it systematically. For this purpose, uniaxial restrained shrinkage tests and tensile tests were performed on large-scale SFRC specimens. The parameters studied in the experimental program were the fibre content (0-100 kg/m3), the fibre geometry, and the water to cement ratio of the concrete matrix (w/c = 0.40-0.80). The test results tend to indicate that multiple cracking is not a property of SFRC as such, at least within the range of concrete matrices and fibre contents investigated and that were intended to be compatible with practical considerations. While it does not mean that fibre reinforcement is not effective in terms of crack control, it is important to be careful in the analysis of test results where the effect of the restraining and exposure conditions might have been significant.Key words: cracking, drying shrinkage, fibre-reinforced concrete, multiple cracking, repairs, restrained shrinkage, steel fibres, tension.


2014 ◽  
Vol 20 (3) ◽  
pp. 380-379 ◽  
Author(s):  
Adam Zofka ◽  
Miglė Paliukaitė ◽  
Audrius Vaitkus ◽  
Dominika Maliszewska ◽  
Ramandeep Josen ◽  
...  

This paper presents a study on the effects of casting procedure and resulting fibre orientation on the properties of Ultra-High Performance Fibre Reinforced Concrete (UHPFRC). To investigate the impact of fibre orientation in the UHPFRC specimens, three approaches were employed. First, densities were measured from the top, middle and bottom zones of the cylinders to observe physical changes as the function of cylinder height. Secondly, two engineering fracture tests were performed in both compression and tension, and a comparison of fracture energies was conducted between different cylinder zones. While previous studies have explored the influence of steel fibres on the UHPFRC performance, the Semi-Circular Bending (SCB) and Disc Compact Tension (DCT) experimental setups have not yet been used in the UHPFRC fracture testing. Lastly, samples from different zones were scanned using X-ray computer tomography (X-ray CT). Both visual and digital image analysis of the X-ray scans were conducted in order to observe fibre orientation pattern changes within different zones. Although density calculations showed insignificant differences between different zones, fracture testing exhibited significant differences through the testing process as well as through fracture energy computations. Furthermore, X-ray CT demonstrated considerable differences in spatial fibre orientation with respect to two uniquely defined angles.


2021 ◽  
Vol 4 (3) ◽  
pp. 119
Author(s):  
Muhammad Aditya Ramadhan Hasran ◽  
Dian Noviyanti Agus Imam ◽  
Bambang Sunendar

Background: One of the materials for denture bases is heat-cured acrylic resin (PMMA). This material still lacks impact strength as a mechanical strength property. The addition of reinforcing material is known to increase the mechanical strength of PMMA. One of the reinforcing materials added to PMMA is nano cellulose from rice husks, one of the wastes from agricultural products. Purpose: This study aims to determine rice husk nano cellulose's addition to the PMMA denture base's impact strength. Method:  The research sample consisted of six groups, each group consisting of 8 samples selected by simple random. The PI, P2, P3, P4, P5, and K groups were PMMA with 1%, 2%, 3%, 4%, 5% nano cellulose, and without nano cellulose. Result: Mean impact strength test results were 41.50 x 10-3 ± 3.891 J / mm2 for P1, 44.13 x 10-3 ± 3,980 J / mm2 for P2, 45.63 x 10-3 ± 4,438 J / mm2 for P3, 46.87 x 10-3 ± 4,824 J / mm2 for P4, 49.12 x 10-3 ± 4.016 J / mm2 for P5 and 36.25 x 10-3 ± 1.982 J / mm2 for K. One way Anova test results with p-value of 0.000 indicates differences in the six groups (p<0.05). Conclusion: This study concludes that the impact strength value of PMMA with the addition of rice husk nano cellulose has increased compared to the control group without the addition of rice husk nano cellulose.


Fibers ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 64
Author(s):  
Roman Fediuk ◽  
Mugahed Amran ◽  
Sergey Klyuev ◽  
Aleksandr Klyuev

The use of fiber in cement materials is a promising and effective replacement for bar reinforcement. A wide range of fiber-reinforced concretes based on composite binders with increased impact strength characteristics have been developed. The synthesized composites included the composite binder made of Portland cement, silica, and carbonate additives. Basalt and steel were used as fibers. The nature of the influence of the composition and manufacturing technology of cement composites on the dynamic hardening coefficient has been established, while the growth of these indicators is achieved by creating a denser interfacial transition zone between the cement paste, aggregate, and fiber as a result of improving the homogeneity of the concrete mixture and controlling the consistency. Workability indicators (slump flow up to 730 mm; spreading time up to a diameter of 50 cm is up to 3 s) allow them to be classified as self-compacting concrete mixtures. An increase in the values of the impact strength coefficient by a factor of 5.5, the dynamic hardening coefficient by almost 70% as a result of interfacial interaction between fibers and binder matrix in the concrete composite, as well as absorption of impact energy by fiber, was revealed. The formula describing the effect of the loading rate on the coefficient of dynamic hardening of fiber-reinforced concrete has been refined. The fracture processes of the obtained materials have been established: after the initiation of primary cracks, the structure of the composite absorbs impact energy for a long time, while in the inelastic range (the onset of cracking and peak loads), a large number of secondary cracks appear.


Sign in / Sign up

Export Citation Format

Share Document