scholarly journals Setting Time of Granite Powder Blended Banana Fibre Reinforced High Performance Concrete

2020 ◽  
Vol 9 (4) ◽  
pp. 891-896
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Setting Time ◽  
Hardened Concrete ◽  
Optimum Level ◽  
Fibre Reinforced Concrete ◽  
Banana Fibre ◽  
Granite Powder

The investigation is intended to analyse the variations in setting time behaviour of high performance fibre reinforced concrete (HPFRC) after adding granite powder as substitute for cement. The replacement of cement by granite powder was consider at the rate of 0, 5, 10, 15 and 20%. In order to improve the performance of concrete, banana fibres are added in concrete at 0.25, 0.5, 0.75, 1.0, and 1.25% by weight of cement. High strength concrete with M50 grade was designed and investigated in this study. The investigation was carried out in two stages, the stage one was predicting the optimum level of adding banana fibre based on the strength performance and the stage two was evaluating the variations in setting time performance of hardened concrete due to addition of granite powder. The setting time of concrete was conducted using penetration resistance test as per IS: 8142-1976. The slump value of the HPFRC was maintained by 80-100 mm and the dosage of superplasticizer was modified accordingly without varying the w/c ratio. Based on the results obtained in this investigation, 1% banana fibre was taken for developing the fibre reinforced concrete without affecting the 28 days compressive strength. The substitution of granite powder beyond 15% increases the setting time significantly and also affect the strength of HPFRC. The relationship between the setting time and 28 days compressive strength was predicted.

scholarly journals Performance of ultra-high performance fibre reinforced concrete plates under impact loads

2021 ◽  
Author(s):  
Hesham Othman
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Fracture Energy ◽  
High Performance ◽  
Steel Reinforcement ◽  
Fibre Content ◽  
Fibre Reinforced Concrete ◽  
Concrete Plates ◽  
High Performance Fibre

The next generation of concrete, Ultra-High Performance Fibre Reinforced Concrete (UHP-FRC), exhibits exceptional mechanical characteristics. UHP-FRC has a compressive strength exceeding 150 MPa, tensile strength in the range of 8-12 MPa, and fracture energy of several orders of magnitudes of traditional concrete. The focus of this research is to investigate and analyze the advantage of using UHP - FRC in impact resistance structures. To achieve these goals, two experimental testing programs and major numerical investigations have been conducted. The material experimental investigation has been conducted to determine the effects of strain rate on UHP - FRC. Two parameters are investigated, namely: compressive strength (80, 110, 130, and 150 MPa); and steel fibre content (0, 1, 2, and 3%). Experimental results showed that the rate sensitivity decreases with the increase in the compressive strength ; and the dynamic enhancement of tensile strength is inversely proportional to the fibre content. The structural impact testing program focuses on the dynamic response of full - scale reinforced concrete plates as well as generating precise impact measurements. Twelve reinforced plates with identical dimensions are tested under high-mass low-velocity multi-impacts. The investigated parameters include: concrete type (NSC, HSC, and UHP - FRC), fibre volume content, and steel reinforcement ratio. The results showed that the use of UHP -FRC instead of NSC or HSC is able to change the failure mode from punching to pure flexural; and UHP -FRC containing 3% fibre has superior dynamic properties. For plates with identical steel reinforcement, the total impact energy of UHP-FRC plate containing 3% fibres is double the capacity of UHP - FRC plate containing 2% fibres , and 18 times the capacity of NSC plate. A three-dimensional finite element analysis has been performed using ABAQUS/Explicit to model multi-impacts on RC plates and the applicability is verified using existing experimental data. Concrete damage plasticity (CDP) model is adapted to define UHP - FRC. The CDP constitutive model parameters for the new material are calibrated through a series of parametric studies. Computed responses are sensitive to CDP parameters related to the tension, fracture energy, and expansion properties. The analytical results showed that the existing CDP model can predict the response and crack pattern of UHP - FRC reasonably well.

Behaviour of Different Types of Concrete under Impact and Quasi-Static Loading

2013 ◽  
Vol 486 ◽  
pp. 295-300 ◽  
Author(s):  
Petr Máca ◽  
Petr Konvalinka ◽  
Manfred Curbach
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Impact Loading ◽  
High Performance ◽  
High Performance Concrete ◽  
Fibre Reinforced Concrete ◽  
Static Conditions ◽  
Direct Tensile ◽  
Direct Tensile Strength ◽  
The Impact

This paper describes mixture formulation of Ultra High Performance Fibre Reinforced Concrete (UHPFRC) with 2% of fibres by volume and its response to quasi-static and dynamic impact loading. The UHPFRC mixture was prepared using locally available constituents and no special curing or mixing methods were used for its production. In addition, the mechanical parameters of three other types of concrete, i.e. normal strength concrete (NSC), fibre reinforced concrete (FRC) and high performance concrete (HPC) is compared. The main properties assessed throughout the experimental work are compressive, flexural and direct tensile strength as well as response of tested concretes to impact flexural loading. The impact loading is produced by a vertically falling weight of 24 kg from the height of 1 m on concrete prisms. The strain rate increase corresponds to low-velocity impacts such as vehicle crash or falling rocks. Compressive strength of UHPFRC exceeded 130 MPa and its direct tensile strength was 10.3 MPa. This type of concrete also exhibited strain hardening both in flexure under quasi-static conditions and during impact. Based on the comparison of impact reactions, it was concluded that the resistance of UHPFRC to impact loading is superior compared to the referent types of concretes (NSC, FRC, HPC).

scholarly journals Probabilistic fatigue analysis of ultra-high-performance fibre-reinforced concrete under thermal effects

2018 ◽  
Vol 165 ◽  
pp. 12001
Author(s):  
José D. Ríos ◽  
Héctor Cifuentes
Keyword(s):  
Reinforced Concrete ◽  
Thermal Effects ◽  
High Performance ◽  
High Performance Concrete ◽  
Fatigue Behaviour ◽  
Fibre Reinforcement ◽  
Fibre Reinforced Concrete ◽  
Ultra High Performance Concrete ◽  
Polypropylene Fibres ◽  
High Performance Fibre

This paper describes the influence of the temperature and the fibre reinforcement on the flexural fatigue behaviour of an ultra-high-performance fibre-reinforced concrete. Three-point bending fatigue tests were carried out for an ultra-high-performance concrete subjected to different temperatures ranging from room temperature up to 300 ºC and considering three different types of reinforcement: a) steel fibres, b) hybrid steel and polypropylene fibres and c) non-reinforced (reference matrix). The fatigue behaviour was assessed from the S-N fields obtained through a probabilistic fatigue model developed by Castillo and Fernández-Canteli. The influence of the type of reinforcement on the fatigue behaviour was analysed by SN curves. An analysis of the thermal effects in the fatigue life of the ultra-high-performance concrete has also been carried out. The results showed the most suitable fibre reinforcement among the analysed options to get the best fatigue behaviour in accordance to the exposure temperature.

scholarly journals The Influence of Ambient Temperature on High Performance Concrete Properties

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4646
Author(s):  
Alina Kaleta-Jurowska ◽  
Krystian Jurowski
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Curing Temperature ◽  
Hardened Concrete ◽  
Water Penetration ◽  
Ambient Temperatures ◽  
Freeze Thaw ◽  
Air Content ◽  
Flow Table

This paper presents the results of tests on high performance concrete (HPC) prepared and cured at various ambient temperatures, ranging from 12 °C to 30 °C (the compressive strength and concrete mix density were also tested at 40 °C). Special attention was paid to maintaining the assumed temperature of the mixture components during its preparation and maintaining the assumed curing temperature. The properties of a fresh concrete mixture (consistency, air content, density) and properties of hardened concrete (density, water absorption, depth of water penetration under pressure, compressive strength, and freeze–thaw durability of hardened concrete) were studied. It has been shown that increased temperature (30 °C) has a significant effect on loss of workability. The studies used the concrete slump test, the flow table test, and the Vebe test. A decrease in the slump and flow diameter and an increase in the Vebe time were observed. It has been shown that an increase in concrete curing temperature causes an increase in early compressive strength. After 3 days of curing, compared with concrete curing at 20 °C, an 18% increase in compressive strength was observed at 40 °C, while concrete curing at 12 °C had a compressive strength which was 11% lower. An increase in temperature lowers the compressive strength after a period longer than 28 days. After two years of curing, concrete curing at 12 °C achieved a compressive strength 13% higher than that of concrete curing at 40 °C. Freeze–thaw performance tests of HPC in the presence of NaCl demonstrated that this concrete showed high freeze–thaw resistance and de-icing materials (surface scaling of this concrete is minimal) regardless of the temperature of the curing process, from 12 °C to 30 °C.

scholarly journals Optimizing the Mechanical Properties of Ultra-High-Performance Fibre-Reinforced Concrete to Increase Its Resistance to Projectile Impact

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5098
Author(s):  
Anna L. Mina ◽  
Konstantinos G. Trezos ◽  
Michael F. Petrou
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Fibre Reinforced Concrete ◽  
Direct Tension ◽  
Steel Fibres ◽  
Projectile Impact ◽  
Binder Ratio ◽  
High Performance Fibre

This study describes an extensive experimental investigation of various mechanical properties of Ultra-High-Performance Fibre-Reinforced Concrete (UHPFRC). The scope is to achieve high strength and ductile behaviour, hence providing optimal resistance to projectile impact. Eight different mixtures were produced and tested, three mixtures of Ultra-High-Performance Concrete (UHPC) and five mixtures of UHPFRC, by changing the amount and length of the steel fibres, the quantity of the superplasticizer, and the water to binder (w/b) ratio. Full stress–strain curves from compression, direct tension, and flexural tests were obtained from one batch of each mixture to examine the influence of the above parameters on the mechanical properties. The Poisson’s ratio and modulus of elasticity in compression and direct tension were measured. Additionally, a factor was determined to convert the cubic strength to cylindrical. Based on the test results, the mixture with high volume (6%) and a combination of two lengths of steel fibres (3% each), water to binder ratio of 0.16% and 6.1% of superplasticizer to binder ratio exhibited the highest strength and presented great deformability in the plastic region. A numerical simulation developed using ABAQUS was capable of capturing very well the experimental three-point bending response of the UHPFRC best-performed mixture.

scholarly journals Numerical Analysis of Strength Capacity of High-Performance Reinforced Concrete Columns with Varied Parametric Study

2020 ◽  
Vol 14 (1) ◽  
pp. 141-151
Author(s):  
Hadi N. G. Al-Maliki
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Load Capacity ◽  
Axial Loading ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
Strength Capacity ◽  
The Moment

Introduction: This study includes the analysis of the strength capacity of high performance reinforced concrete columns subjected to concentric axial loading. The main variables are based on the compressive strength of concrete and steel reinforcing ratios. All the columns are fixed, supported by two ends. Methods: This study is based on a calculation done according to ACI Code-318M-2011 equations for columns analysis to evaluate the ultimate strength then applied these load on samples to compare between them by software program Prokon V.3. The comparison is based on reinforcement ratio and moment resistance capacity. Results: The analysis results show that when increasing the main reinforcement with high-performance concrete led, there will be an increased load capacity by about (40 to 215%) and moment resistance capacity by about (35 to 50%) with the same load conditions. According to the analysis of the results, the moment resistance capacity of constant sample value with different reinforcing ratio leads to these resist depending on the load applied, and the concrete compressive strength of columns. Conclusion: Reasonable correlation of the results is demonstrated, which ensured the adequacy of the analysis by test program, both hand calculation and software Prokon.V.3.

Experimental Study on Basic Properties of Fair-Faced Concrete for Urban Bridge

2013 ◽  
Vol 438-439 ◽  
pp. 1156-1159 ◽  
Author(s):  
Li Hui Jin ◽  
Xiao Lu Ma ◽  
Xiao Ke Li
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Surface Brightness ◽  
High Performance Concrete ◽  
Hardened Concrete ◽  
Basic Properties ◽  
Mix Proportion ◽  
Water To Cement Ratio ◽  
Color Uniformity

As the high-performance concrete with remarkable characteristics of artistic presentation and ecological sense, fair-faced concrete is becoming more and more attention by the department of urban construction. As part of the research project, this paper gives the supplement study of the mix proportion and basic properties of C50 fair-faced concrete, and summarizes the experimental results of the apparent quality of C30 and C50 fair-faced concrete affected by the mold releases. Considering the parameters of water to cement ratio, cement dosage, percent of pulverized fly ash, sand ratio, water reducer and mold releases, the workability of fresh concrete and the compressive strength of hardened concrete at 7 days, 28 days and 56 days, as well as the apparent quality and surface brightness were measured, the mix proportions of C30 and C50 fair-faced concretes for construction of urban bridge were determined. Based on the measurements of surface brightness, color uniformity, resistance to water penetration, stain resistance and compressive strength of fair-faced concrete, the formwork lacker can be firstly selected as the mold release, and the mix oil (diesel: machine oil=3:7) can be the alternative selection.

scholarly journals Influence of Fiber Addition on the Properties of High-Performance Concrete

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3736
Author(s):  
Szymon Grzesiak ◽  
Matthias Pahn ◽  
Milan Schultz-Cornelius ◽  
Stefan Harenberg ◽  
Christoph Hahn
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Limit State ◽  
Experimental Tests ◽  
Absorption Capacity ◽  
Fiber Reinforced Concrete ◽  
Hardened Concrete ◽  
Fiber Reinforced

High performance fiber-reinforced concrete (HPFRC) has been frequently investigated in recent years. Plenty of studies have focused on different materials and types of fibers in combination with the concrete matrix. Experimental tests show that fiber dosage improves the energy absorption capacity of concrete and enhances the robustness of concrete elements. Fiber reinforced concrete has also been illustrated to be a material for developing infrastructure sustainability in RC elements like façade plates, columns, beams, or walls. Due to increasing costs of the produced fiber reinforced concrete and to ensure the serviceability limit state of construction elements, there is a demand to analyze the necessary fiber dosage in the concrete composition. It is expected that the surface and length of used fiber in combination with their dosage influence the structure of fresh and hardened concrete. This work presents an investigation of the mechanical parameters of HPFRC with different polymer fiber dosage. Tests were carried out on a mixture with polypropylene and polyvinyl alcohol fiber with dosages of 15, 25, and 35 kg/m3 as well as with control concrete without fiber. Differences were observed in the compressive strength and in the modulus of elasticity as well as in the flexural and splitting tensile strength. The flexural tensile strength test was conducted on two different element shapes: square panel and beam samples. These mechanical properties could lead to recommendations for designers of façade elements made of HPFRC.

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