Effect of basalt, polypropylene and macro-synthetic fibres on workability and mechanical properties of self-compacting concrete

2019 ◽  
Vol 5 (2) ◽  
pp. 35
Author(s):  
Zinnur Çelik ◽  
Ahmet Ferhat Bingöl
Keyword(s):  
Mechanical Properties ◽  
Fresh Concrete ◽  
The Self ◽  
The Other ◽  
Fibre Content ◽  
Hardened Concrete ◽  
Fibre Reinforced Concrete ◽  
Self Compacting Concrete ◽  
Concrete Properties ◽  
Hardened Properties

In this study, the effects of different fibre types on the workability and mechanical properties of self-compacting concrete were investigated. Fresh and hardened properties of self-compacting concrete, different fibre content 0.90, 1.35 and 1.80 kg/m3 were evaluated using basalt, polypropylene and macro synthetic fibres with different fibre lengths of 24, 19 and 40 mm, respectively. The properties of fresh concrete were evaluated in terms of slump flowing, viscosity and flowability. In addition, compressive, flexural and splitting tensile strength were obtained from hardened concrete properties. To characterize mechanical properties 90 specimens were experimentally tested. The results show that the use of fibre reduces the workability of self-compacting concrete. On the other hand, tensile and flexural strength of the self-compacting fibre reinforced concrete increased with increasing fibre content, but it was determined that the fibre addition had no significant effect on the compressive strength.

scholarly journals GGBS based alkali activated fine aggregate in concrete - Properties at fresh and hardened state

2021 ◽  
Vol 13 (1) ◽  
pp. 47-53
Author(s):  
G. Lizia Thankam ◽  
T.R. Neelakantan ◽  
S. Christopher Gnanaraj
Keyword(s):  
Mechanical Properties ◽  
Alkaline Solution ◽  
Elevated Temperatures ◽  
Fresh Concrete ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
River Sand ◽  
Complete Replacement ◽  
Concrete Properties ◽  
Fine Aggregates

Abstract Scarcity of the construction materials, peculiarly the natural river sand has become a serious threat in the construction industry. Though many researchers of developed and developing countries are trying to find alternative sources for the same, the complete replacement of the fine aggregate in concrete is crucial. Geopolymer sand developed from the Industrial waste (Ground granulated blast furnace slag - GGBS) is an effective alternative for the complete replacement of the natural sand. The GGBS based geopolymer sand (G-GFA) was tested for physical and chemical properties. Upon the successful achievement of the properties in par with the natural river sand, the fresh properties (fresh concrete density & slump) and hardened properties (compressive strength, tensile strength & flexural strength) of the concrete specimens developed with G-GFA were studied. The G-GFA is obtained by both air drying (AD-G-GFA) and oven drying (OD-F-GFA) after the dry mixing of the alkaline solution and GGBS for about 10 min. Thus, developed fine aggregates were studied separately for the fresh and hardened concrete to optimize the feasible one. Superplasticizer of 0.4% is included in the concrete mix to compensate the sightly hydrophilic nature of the fine aggregates produced. The mechanical properties of the concrete with G-GFA are observed to be more than 90% close to that of the concrete developed with natural river sand. Thus, both the fresh and mechanical properties of the G-GFA concrete specimens resulted in findings similar to those of the control specimen developed with natural river sand reflecting the plausibility of G-GFA as a complete replacement choice to the fine aggregate in the concrete industry. The flaky GGBS particles merge well with the alkaline solution at room temperature itself since the former gets dried at elevated temperatures. Thus, more feasible fresh concrete properties and mechanical properties were recorded for the AD-G-GFA than the OD-G-GFA.

scholarly journals Lightweight self-compacting concrete with sintered fly-ash aggregate

2018 ◽  
Vol 27 (3) ◽  
pp. 328-337
Author(s):  
Dorota Małaszkiewicz ◽  
Daniel Jastrzębski
Keyword(s):  
Fly Ash ◽  
Fresh Concrete ◽  
Strength Loss ◽  
Partial Replacement ◽  
Hardened Concrete ◽  
Self Compacting Concrete ◽  
Natural Sand ◽  
Concrete Properties ◽  
Slump Flow ◽  
Passing Ability

The article presents the results of research assessing the possibility of making LWSCC from the locally produced sintered fly ash aggregate CERTYD. Two methods of preliminary LWA preparation were applied: pre-soaking with water and coating with a film of cement paste. The following properties of fresh LWSCC were evaluated: slump-flow, time T500 and passing ability using L-Box. Partial replacement of natural sand by fine LW sand (0/0.5 mm) improved filling and passing abilities of fresh concrete, reduced slightly the bulk density, but it resulted in compressive strength loss by 12-18%. In terms of both fresh and hardened concrete properties it is more favorable to use only fine LW sand as natural sand replacement. Considering fresh concrete properties paste impregnation of LW aggregate is more efficient than saturation with water.

Influence of Concrete Mix Transportation with Inertia Conveyor on Concrete Properties

2017 ◽  
Vol 265 ◽  
pp. 97-102 ◽  
Author(s):  
S.G. Osmanov
Keyword(s):  
Mechanical Properties ◽  
Fresh Concrete ◽  
Precast Concrete ◽  
Physical And Mechanical Properties ◽  
Hardened Concrete ◽  
Engineering Process ◽  
Concrete Properties ◽  
Concrete Mix ◽  
Ready Mix Concrete ◽  
Asymmetric Oscillations

The practical expediency of the study of physical and mechanical properties of concrete, received from the mix, exposed at its feeding to the point of placement to the transportation with the inertia conveyor by means of original technology, which shows its competitiveness at factories producing precast concrete units, is proved. The experimental procedures of the research performed by the authors, where they analyzed the process of transportation relating to the use of ready-mix concrete on the dense aggregate, are described. The data on the effect of received previously rational values of the major parameters of engineering process studied (the parameters of asymmetric oscillations of work member of the conveyor and the thickness of the mix layer moved by it) both on the homogeneity of fresh concrete and the strength and strength homogeneity of hardened concrete are represented and analyzed.

Mechanical Properties of Engineered Cementitious Composites Mixture

2014 ◽  
Vol 567 ◽  
pp. 428-433 ◽  
Author(s):  
Bashar S. Mohammed ◽  
Muhammad Hafiz Baharun ◽  
Muhd Fadhil Nuruddin ◽  
Odu Paul Duku Erikol ◽  
Nadhir Abdulwahab Murshed
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
The Self ◽  
Cementitious Composite ◽  
Fresh Properties ◽  
Self Compacting Concrete ◽  
Engineered Cementitious Composite ◽  
Hardened Properties ◽  
Pva Fiber

The aim of the research is to develop engineered cementitious composite mixtures satisfying the self-compacting concrete requirements and to evaluate the hardened properties of self-compacted ECC mixtures. To enhance the concrete performance, PVA is used. The PVA improved some characteristics and properties of the concrete. Ten mixes with different Polyvinyl Alcohol (PVA) fiber contents (0.0%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5% and 5.0%) have been prepared. Three cubes (100mm x 100mm x 100mm), three beams (100mm x 100mm x 500mm) and three cylinders (150mm diameter and 300mm height) have been cast for each mix and tested at the age of 7 and 28 days for compressive strength and at age of 28 days for splitting and flexural strength. The V-funnel, L-box and slump test also have been conducted to access the fresh properties like workability and flowability of the concrete. The results indicated the increase in the strength of the concrete and the formulas for predicting the compressive, splitting and flexural strength from PVA (%) has been developed.

Performance and Uniformity of Self-Compacting Concrete

2005 ◽  
Vol 1914 (1) ◽  
pp. 71-80
Author(s):  
Mohamed Nagib Abou-Zeid ◽  
Mohamed Samir Roushdy
Keyword(s):  
Coarse Aggregate ◽  
Fresh Concrete ◽  
Mechanical Vibration ◽  
Hardened Concrete ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Rebound Hammer ◽  
Slump Flow ◽  
Hardened Properties ◽  
The Impact

Self-compacting concrete (SCC) can be achieved by adjusting mix proportions and incorporating adequate admixtures, such as viscosity-modifying (VM) admixtures, with no vibration. Yet, the impact of the mix proportions and the role played by the VM admixtures as opposed to those played by superplasticizer admixtures are not fully understood. There also seems to be no unique means for assessment of such concrete, and the correlation between various tests needs further work. This study aims to achieve a better understanding of the influence of mix proportions on the properties of SCC. Twenty-six mixtures were prepared with various water-to-cementitious material ratios, fine aggregate-to-coarse aggregate ratios, and admixture dosages. Fresh concrete tests, including slump flow, L-box, U-box, and hardened concrete tests, including hardened density, compressive and flexural strength, as well as the rebound hammer tests, were performed. The uniformity of SCC properties among the column specimens was examined. The results revealed that adjustment of the mix proportions has a major impact on the fresh and hardened properties of SCC. The fresh concrete tests were found to correlate well with one another, and the SCC strength was comparable to that of reference concrete made with mechanical vibration. Yet, the components of the SCC examined exhibited a remarkable uniformity of properties. Further work that should involve large specimens in which concrete properties are evaluated in various locations is needed.

scholarly journals Investigation of the Effect of Freeze-thaw Cycles on the Mechanical Properties of Hardened Self-compacting Concrete

2020 ◽  
Author(s):  
Tuncay Kap
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Statistical Analysis ◽  
Fresh Concrete ◽  
The Other ◽  
Unit Weight ◽  
Self Compacting Concrete ◽  
Freeze Thaw ◽  
The Core ◽  
Average Compressive Strength

This study investigated the effects of freeze-thaw cycles on the mechanical properties of hardened self-compacting concrete for varying column heights. A column (100×20×300 cm) was fabricated by C30 self-compacting concrete in the laboratory and 10 cube samples (10x10x10 cm) were taken from fresh concrete as the references. After a period of 28 days, 160 core specimens (Ø67 mm in diameter) were taken from different column heights. Unit weight, water absorption, compressive strength, and freeze-thaw tests were performed on these 170 (10 reference cubic and 160 core) samples. The mechanical properties of the core specimens before freeze-thaw and after 8-56 freeze-thaw cycles were reported for varying column heights. The average compressive strength value of the reference cubic samples was determined as 40.28 MPa, while the compressive strengths of the core specimens before freeze-thaw were ranged from 40.25 MPa to 49.62 MPa, impying an increase in compressive strength values up to 23.18% compared to the reference cubic samples. Compressive strengths of the specimens subjected to 8 and 56 freeze-thaw cycles varied between 38.71‒48.07 MPa and 31.72‒39.11 MPa, respectively. Statistical analysis revealed that the compressive strength of the concrete exposed to 56 freeze-thaw cycles was significantly different from that of the other specimens.

Coloured Concrete with Focus on the Properties of Pigments

2014 ◽  
Vol 1054 ◽  
pp. 248-253 ◽  
Author(s):  
Jaroslava Koťátková ◽  
Pavel Reiterman
Keyword(s):  
Mechanical Properties ◽  
Characteristic Feature ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Fresh Concrete ◽  
Cement Content ◽  
The Other ◽  
Hardened Concrete ◽  
Concrete Matrix

In this paper the possibilities of colouring concrete and the use of pigments are presented. There are two groups of pigments with respect to its manufacture (organic and inorganic) and three different forms available on market: powder, granulates and slurry. Next to the influences of other concrete components the effects of fine pigment particles on the properties of fresh and hardened concrete are introduced. Because of the higher need of water the workability of each mixture is affected. With the increasing specific surface area of pigment the flow of fresh concrete decreases. On the other hand this characteristic feature causes slightly higher density of concrete matrix which results in better durability. Optimal dosages differs depending on the form of pigment, for powders it is about 5% of the weight of cement content. Higher amounts don ́t bring about higher tinting strength and in the case of more than 10 % its mechanical properties can be negatively affected. An example of colour evaluation as well as utilization of recycled materials as colouring agents are also mentioned.

scholarly journals Proportioning Self Compacting Concrete in Hot Weather Utilizing Limestone Powder

2019 ◽  
pp. 6-10
Author(s):  
Yousif Hummaida Ahmed
Keyword(s):  
Compressive Strength ◽  
Cement Content ◽  
The Self ◽  
Limestone Powder ◽  
Hardened Concrete ◽  
Self Compacting Concrete ◽  
Concrete Properties ◽  
Slump Flow ◽  
Hot Weather ◽  
Powder Content

Self-compacting concrete (SCC) is a special type of concrete able to flow and compact under its self-weight. The SCC requires high powder content (mainly of cement) up to 600kg/m3 to achieve its properties. This will be problematic if all cement content in the powder exceeded 400 kg/m3used in hot weather of Sudan. This paper investigates addition of Sudanese limestone powder (LSP) to reduce cement content. The LSP dosages between 20% and 28 % (by cement weight) are used in six mixes having maximum cement content 380kg/m3. Results show that five trial mixes achieved the self-compactibility tested by slump flow, sieve segregation, V-funnel and U-box tests. Compressive strength of these mixes show that the LSP increases strength with dosage. Therefore, further investigations of hardened concrete properties are recommended for the successful mixes to be applied in real projects in the Sudan. Also, it has been found that dry batching and forced-action pan mixers are the most suitable for producing SCC with high homogeneity compared to commercial tilted-drum mixers.

scholarly journals Effect of Using Hybrid Polypropylene and Glass Fibre on the Mechanical Properties and Permeability of Concrete

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3786 ◽  
Author(s):  
Abubaker A. M. Ahmed ◽  
Yanmin Jia
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Glass Fibre ◽  
Single Fibre ◽  
Air Permeability ◽  
Fibre Content ◽  
Peak Performance ◽  
Fibre Reinforced Concrete ◽  
Performance Limit ◽  
Hybrid Fibre

A comprehensive program of experiments consisting of compression, uniaxial compression, direct shear, flexural as well as splitting tensile and air permeability tests were performed to analyse the effect of the level of fibre dosage and the water–cement ratio on the physical properties of hybrid fibre-reinforced concrete (HFRC). Two types of fibres were studied in terms of their effect on the properties of HFRC. The results indicated that the mechanical properties of concrete were significantly improved by increasing the fibre content. However, increasing the percentage fibre content past a certain peak performance limit (0.9% glass fibre (GF) and 0.45% polypropylene fibre (PPF)) led to a decrease in strength compared to reference mixes. Additionally, the incorporation of hybrid fibres yielded an increase in air permeability in the tested specimens. The results showed that the strength-related properties of HFRC were superior to the properties of single fibre-reinforced concrete.

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.

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