Impact of Steel Fibers on Workability and Properties of UHPC

2016 ◽  
Vol 249 ◽  
pp. 57-61 ◽  
Author(s):  
Milan Rydval ◽  
Tomáš Bittner ◽  
Jiří Kolísko ◽  
Šárka Nenadálová
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Fresh Concrete ◽  
Mixture Design ◽  
Steel Fibers ◽  
Hardened Concrete ◽  
Hardened Cement ◽  
The Impact

This paper is focused on properties of fresh and hardened cement-based composite Ultra-High Performance Concrete with regard to different volume fraction of short brass coated steel fibers BASF MASTERFIBER® 482. Workability of fresh concrete and basic mechanical properties (tensile strength in bending, compressive strength) of hardened UHPC were found out. The workability of fresh concrete was measured by small mortar Haegermann cone. Percentage differences at cost were obtained at hardened concrete, too. The aim of the first experimental part of the research was the impact of volume fraction of steel fibers according to workability of fresh concrete and also according to mechanical properties of hardened UHPC with the same volume fraction of each component of the mixture, only the volume fraction of the steel fibers was different at each mixture. The mixture design of UHPC was changed to maintaining the workability of fresh concrete at the second part of the research. The workability at mixture with dosage of steel fibers of 300 kg/m3 measured by Haegermann cone was around 300 mm. In the framework of grant project GAČR 15-05791S the basic mechanical properties of hardened fine-grained cementitious composite material UHPC at small beams size of 160/40/40 mm and beams size 300/70/70 mm were determined. The aim of the research project was not only the determination of basic mechanical properties for each mixture design but also workability assessment and costs linked with higher amount of the volume fracture of steel fibers.

scholarly journals Developing Geopolymer Concrete Properties by Using Nanomaterials and Steel Fibers

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
E. Rabiaa ◽  
R. A. S. Mohamed ◽  
W. H. Sofi ◽  
Taher A. Tawfik
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Sodium Hydroxide ◽  
Steel Fiber ◽  
Splitting Tensile Strength ◽  
Steel Fibers ◽  
Hardened Concrete ◽  
Geopolymer Concrete ◽  
Alkaline Activator ◽  
The Impact

This research investigates the simultaneous impact of two different types of steel fibers, nanometakaolin, and nanosilica on the mechanical properties of geopolymer concrete (GPC) mixes. To achieve this aim, different geopolymer concrete mixes were prepared. Firstly, with and without nanomaterials (nanosilica and nanometakaolin) of 0, 2%, 4%, 6%, and 8% from ground granulated blast furnace slag (GGBFS) were used. Secondly, steel fiber (hooked end and crimped) content of (0, 0.5%, 1, and 1.5%) was used. Thirdly, optimum values of nanomaterials with the optimum values of steel fiber were used. Crimped and hooked-end steel fibers were utilized with an aspect ratio of 60 and a length of 30 mm. Geopolymer mixes were manufactured by using a constant percentage of alkaline activator to binder proportion equal to 0.45 with GGBFS cured at ambient conditions. For alkaline activator, sodium hydroxide molar (NaOH) and sodium hydroxide solution (NaOH) were used according to a proportion (Na2SiO3/NaOH) of 2.33. The hardened concrete tests were performed through the usage of splitting tensile strength, flexural, and compressive experiments to determine the impact of steel fibers, nanometakaolin, and nanosilica individually and combined on performance of GPC specimens. The results illustrated that using a mix composed of the optimum steel fibers (1% content) accompanied by an optimum percentage of 6% nanometakaolin or 4% nanosilica demonstrated a significant enhancement in the mechanical properties of GPC specimens compared to all other mixtures. Besides, the impact of using nanomaterials individually was found to be predominant on compressive strength on GPC specimens especially with the usage of the optimum values. However, using nanomaterials individually compared to using the steel fibers individually was found to have approximately the same splitting tensile strength and flexural performance.

Nanoadditives - Future of High Performance Concrete

2017 ◽  
Vol 908 ◽  
pp. 83-87
Author(s):  
Martin Labaj ◽  
Jaroslav Válek ◽  
Tomáš Jarolím ◽  
Lucia Osuská
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Concrete Surface ◽  
Cement Stone ◽  
Hardened Cement ◽  
Concrete Technology ◽  
High Quality ◽  
Long Time ◽  
The Impact

These days it is almost impossible to imagine the technology of high performance concrete without the use of any kind of additive. Whether it is a material capable of achieving high strength, excellent mobility of the fresh mix without losing cohesion or producing high quality architectural concrete surface, microadditives have their certain place for a long time now. Although the research in this field still has something to offer, it does not hurt to try to consider the future and imagine the path that will be taken in the production of high performance concrete of next generation. The article deals with the possibility of using nanoparticles in concrete technology. These materials can actively participate in the creation of very high-quality cement stone. In addition, due to the extreme reactivity of nanoparticles, these reactions can take place almost immediately after the onset of hydration and during its first hours. The experimental part of the paper assesses the impact of nanoparticles on selected properties of fresh cement paste and hardened cement mortar. In all cases, there was a positive effect and it has been demonstrated that nanoparticles may eventually create a new category of high performance concrete additives.

Preparation of High-Performance Concrete for Adjusting of Possibility of its Usage in Building Practice

2016 ◽  
Vol 722 ◽  
pp. 298-304 ◽  
Author(s):  
Matej Špak
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Local Source ◽  
Hardened Concrete ◽  
Building Practice ◽  
Source Materials ◽  
Limited Possibility

Technology of High-Performance Concrete (HPC) presents one of advanced concrete technologies. In comparison to common concrete, HPC is characterized by much better qualitative parameters both for fresh and hardened concrete. However, utilization of adequate materials as well as specific processes of both the production and handling of fresh concrete is required to achieve the above standard parameters of concrete. Currently, limited possibility of utilization of local source materials with applicable parameters curtails wider production of HPC within the building practice. Results of experimental approval of HPC properties which was prepared from local aggregates are presented in the paper. Used aggregates have not appropriate parameters for application into HPC on its face. Therefore the achieved results show the potential of its applied utilization.

scholarly journals On enhancing the mechanical behavior of ultra-high performance concrete through multi-scale fiber reinforcement

2021 ◽  
Author(s):  
Ketan Ragalwar ◽  
William Heard ◽  
Brett Williams ◽  
Dhanendra Kumar ◽  
Ravi Ranade
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
Underlying Mechanism ◽  
Steel Fibers ◽  
Flexural Behavior ◽  
Steel Wool ◽  
Multi Scale ◽  
Pull Out ◽  
Fiber Matrix

Steel fibers are typically used in ultra-high performance concretes (UHPC) to impart flexural ductility and increase fracture toughness. However, the mechanical properties of the steel fibers are underutilized in UHPC, as evidenced by the fact that most of the steel fibers pull out of a UHPC matrix largely undamaged during tensile or flexural tests. This research aims to improve the bond between steel fibers and a UHPC matrix by using steel wool. The underlying mechanism for fiber-matrix bond improvement is the reinforcement of the matrix tunnel, surrounding the steel fibers, by steel wool. Single fiber pullout tests were performed to quantify the effect of steel wool content in UHPC on the fiber-matrix bond. Microscopic observations of pulled-out fibers were used to investigate the fiber-matrix interface. Compared to the control UHPC mixture with no steel wool, significant improvement in the flexural behavior was observed in the UHPC mixtures with steel wool. Thus, the addition of steel wool in steel fiber-reinforced UHPC provides multi-scale reinforcement that leads to significant improvement in fiber-matrix bond and mechanical properties of UHPC.

Experimental Study of Strengthening and Toughening for Recycled Steel Fiber Reinforced Ultra-High Performance Concrete

2014 ◽  
Vol 629-630 ◽  
pp. 104-111 ◽  
Author(s):  
Gai Fei Peng ◽  
Xu Jing Niu ◽  
Qian Qian Long
Keyword(s):  
Mechanical Properties ◽  
Fracture Energy ◽  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Ultra High Performance Concrete ◽  
Tensile Splitting Strength ◽  
Recycled Steel

This paper presents an experimental investigation on mechanical properties (including compressive strength, tensile splitting strength and fracture energy) of ultra-high performance concrete (UHPC) with recycled steel fiber, compared with none fiber and industrial steel fiber reinforced UHPC. Moreover, the microscopic observation of fracture energy was carried out. All specimens were prepared at 0.18 water /binder (W/B) ratio and the dosage of steel fiber was controlled at 60 kg/m3. The results indicate that recycled steel fiber has a significant effect on enhancing strength and toughness of UHPC. And owing to the crimped shape, higher tensile strength (1800-2000 MPa) and appropriate diameter (1 mm) of recycled steel fiber, the steel fibers of UHPRSFRC will not immediately be pulled off and necking phenomenon is distinct.

scholarly journals Effect of Hybridization of steel fibers on the mechanical properties of high strength concrete

2018 ◽  
Vol 199 ◽  
pp. 11006
Author(s):  
M. Iqbal Khan ◽  
Wasim Abbass
Keyword(s):  
Mechanical Properties ◽  
High Strength Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Research Work ◽  
High Strength ◽  
Steel Fibers ◽  
Flexural Properties ◽  
Strength Concrete ◽  
Total Percentage

The hybridization of fibers for arresting the crack in concrete is a key factor and play an important role to improve mechanical properties of high performance concrete with respect to mono fibers. The effect of hybridization of hooked end steel fibers with different length and diameter on mechanical properties of high strength concrete was investigated in this research work. The different percentages of hook ended fibers (60 mm and 40 mm) are hybridized in the concrete mixture while keeping total percentage of fibers by volume equal to 1%. The compressive and flexural properties with complete load verses deflection curves of hybrid steel fiber reinforced high performance concrete were investigated to find the optimized dosage of hybrid steel fibers. The results showed that the hybridization of fiber provided better compressive and flexural performance. It was also observed from the results that combination of 65% of 60 mm and 35% of 40 mm hooked end fibers proved to be best for enhancement in compressive and flexural properties.

scholarly journals Experimental comparative study of reactive powder concrete: mechanical properties and the effective factors

2018 ◽  
Vol 162 ◽  
pp. 04004 ◽  
Author(s):  
Eyad Kadhem ◽  
Ammar Ali ◽  
Sameh Tobeia
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Modulus Of Elasticity ◽  
High Performance ◽  
High Performance Concrete ◽  
Splitting Tensile Strength ◽  
Steel Fibers ◽  
Reactive Powder Concrete ◽  
Concrete Mechanical Properties ◽  
Reactive Powder

Reactive Powder Concrete (RPC) is a type of ultra-high performance concrete, this dense composite material generally characterized by high cement content, high durability, low porosity, low water/cement ratio and in most cases contains steel fibers as new types of concrete appears, further investigation for their mechanical properties are needed. This work aims to give a better understanding of RPC behavior by deriving formulas to calculate the modulus of elasticity and the splitting tensile strength in relation with compressive strength and steel fibers content. This study is based on data obtained from the experimental investigation done in this work and from others pervious works. The parametric study is based mainly on the silica fume content which is used in four different ratios (12 %, 15 %, 20 % and 25 %), the use of micro steel fibers 15 mm in length, 0.2 mm in diameter and aspect ratio of 75 added in ratios of (0 %, 1 %, 1.5 % and 2 %), and water/cement in ratios of (16 %, 18 %, 20 % and 22 %), respectively. The proposed equations show a better behavior in comparison to some available equations that were used in the estimation of modulus of elasticity and splitting tensile strength of reactive powder concrete, the coefficient of variation for the proposed equations (COV) decrease to 10.677% and 10.455% respectively.

scholarly journals MECHANICAL PROPERTIES OF STRUCTURAL AERATED LIGHTWEIGHT CONCRETE REINFORCED WITH IRON LATHING WASTE

2021 ◽  
Vol 25 (01) ◽  
pp. 100-108
Author(s):  
Samer S. Abdulhussein ◽  
◽  
Ashraf A. Alfeehan ◽  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Modulus Of Elasticity ◽  
Lightweight Concrete ◽  
Volume Fraction ◽  
Hardened Concrete ◽  
Static Modulus ◽  
Flexural Tensile Strength ◽  
Static Modulus Of Elasticity ◽  
The Impact

Currently, the industry of construction requires finding efficient materials to increase the durability and strength as well as decreasing the concrete structure’s total weight. Therefore, an effort was made in this study for examining the impact of adding waste materials such as the iron lathing waste fibers. Iron lathe wastes have been deformed into twisted strips with a width of (4mm) and sieving size of (4.75-10) mm. The experimental investigation has been achieved with the use of four mixes related to light-weight concretes, involving different volumetric ratios of the iron lathing waste fibers as (0%, 1 %, 1.5 %, and 2 %). With the increase in the volume fraction of the lathing waste fibers from 0% to 2%, the results showed that there were a significant increase and improvement in compressive strength, splitting tensile strength, flexural tensile strength, static modulus of elasticity, and dynamic modulus of elasticity by 12%, 67.5%, 134%, 27%, and 26% respectively. This indicates that the iron waste fibers have an important impact in enhancing the mechanical properties of the hardened concrete through the structural change in the concrete matrix.

Effect of PVA Fiber on Mechanical Properties of High-Performance Concrete

2013 ◽  
Vol 438-439 ◽  
pp. 249-252 ◽  
Author(s):  
Zhe Jin ◽  
Cheng Ya Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
High Performance ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Splitting Tensile Strength ◽  
Fiber Volume ◽  
Pva Fiber

An experimental study has been conducted to investigate the effect of the fraction of PVA fiber on the mechanical properties of high-performance concrete. The mechanical properties include compressive strength, splitting tensile strength and compressive elastic modulus. On the basis of the experimental results of the specimens of six sets of mix proportions, the mechanism of PVA fiber acting on these mechanical properties has been analyzed in details. The results indicate that there is a tendency of increase in the compressive strength and splitting tensile strength when the fiber volume fraction is below 0.08%, and the compressive elastic modulus of high-performance concrete decreases gradually with the increasing volume fraction of PVA fiber with appropriate content.

Study on Long-Term Expansive Deformation of Self-Stressing Concrete with Combined Restrictions of Steel Fibers and Steel Bar

2010 ◽  
Vol 452-453 ◽  
pp. 533-536 ◽  
Author(s):  
Huan An He ◽  
Wei Dong ◽  
Zhi Min Wu
Keyword(s):  
Prestressed Concrete ◽  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Volume Fraction ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Expansive Concrete

Self-stressing concrete is sort of expansive concrete with high expansion energy which can induce prestresses with restriction in concrete, and steel fibers also enhance tensile strength of concrete. The combination of these two high performance concrete can be used to improve the cracking resistance of concrete significantly. However, like mechanical prestressed concrete, a stable long-term prestresses (self-stresses) level is a key to exploit the particular advantage of steel fiber reinforced self-stressing concrete. Self-stresses are created by restricting the expansion of self-stressing concrete with steel bars or/and steel fibers, therefore, in this paper a series of tests on long-term expansive deformation of concrete were carried out by means of measuring restrict expansive deformation of self-stressing concrete with restriction of steel fibers. The results of tests showed, based on the three-year recording, that the expansive deformation of steel fiber reinforced self-stressing concrete almost kept the same as that of 28-day without remarkable rebound which indicated that losses of self-stresses were not significant and can meet the design requirements on self-stresses level. In addition, it is proposed on the relationship between restrict expansive deformation and reinforcement ratio of steel rebars under different steel fiber volume fraction from 0-2%.

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