scholarly journals Synergistic Use of Fly Ash and Silica Fume to Produce High-Strength Self-Compacting Cementitious Composites

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 915
Author(s):  
Muhammad Tausif Arshad ◽  
Saeed Ahmad ◽  
Anwar Khitab ◽  
Asad Hanif
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
High Performance ◽  
Cement Mortar ◽  
High Strength ◽  
Industrial Wastes ◽  
Modern World ◽  
Cementitious Composites ◽  
Binary Blend ◽  
Powder Content

High-performance cementitious composites with self-compacting characteristics are gaining due importance in meeting the challenges of the modern world. This experimental study deals with developing high-strength self-compacting cement mortar composites containing a binary blend of silica fume and fly ash. Seven specimens series were prepared with fly ash (FA), ranging from 17.5% to 25%, and silica fume (SF), from 1.25% to 7.5% of the cement mass. The control specimen powder content consists of 80% ordinary portland cement (OPC), 20% FA, and 0% SF; in the remaining six series of specimens, OPC is kept constant, whereas FA is reduced by 1% and SF is increased by 1% subsequently. Rheological behavior, mechanical properties, and microstructural characteristics of the developed high-performance composites were evaluated. The optimum binary blend for achieving the maximum flow spread and flow rate of the cement mortar is reported as 80% FA and 20% SF. For superior mechanical characteristics, optimum powder content was found as 80% OPC, 17.5% FA, and 2.5% SF. Using the proposed binary blend for construction applications will produce high-strength composites and promote sustainable development due to the use of industrial wastes as OPC replacement.

scholarly journals High performance superplasticized silica fume mortars for ferrocement works

2010 ◽  
Vol 8 (2) ◽  
pp. 129-134
Author(s):  
Kumar Rathish
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
High Performance ◽  
Cement Mortar ◽  
Cement Content ◽  
Flow Characteristics ◽  
High Strength ◽  
Experimental Program ◽  
Cement Mortars ◽  
Good Workability

Ferrocement works demand cement mortars of good workability and high strength. Reduction in water-cement ratio combined with a refined pore structure increases the compressive strength in addition to the enhancement of durability characteristics, but the workability decreases. Workability becomes important, as the mortar has to easily penetrate between the layers of the mesh wires. A reasonably workable high strength cement mortar can be obtained by using a high cement content coupled with the use of superplasticizers. These were also found to retain the cohesiveness and check undesirable bleeding and segregation. An experimental program was conducted to study the functional efficacy of an SNF condensate used as a water reducing superplasticizer. The compressive strength and flow characteristics of the mortars were determined to decide their suitability for ferrocement works. The parameters included the mix proportions, the grade of cement, age of curing and the dosage of superplasticizer. It was concluded from the study that the addition of an optimum dosage of superplasticizer improved the workability and strength characteristics of silica fume mortars. There was a late gain in the compressive strength of silica fume mortars.

scholarly journals Mix proportioning of M80 grade Self-Compacting Concrete based on Nan Su Mix design method principles

2018 ◽  
Vol 7 (3.35) ◽  
pp. 52
Author(s):  
S Shrihari ◽  
M V Seshagiri Rao ◽  
V Srinivasa Reddy ◽  
Venkat Sai
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Design Method ◽  
High Strength ◽  
Mix Design ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Mix Proportioning ◽  
Major Factors ◽  
Powder Content

The quest for the development of high strength and high performance concretes has increased considerably in recent times because of the demands from the construction industry. High-performance concretes can be produced at lower water/powder ratios by incorporating these supplementary materials. Fly ash addition proves most economical among these choices, even though addition of fly ash may lead to slower concrete hardening. However, when high strength is desired, use of silica fume is more useful. This paper proposes a mix proportions for M80 grade Self-compacting concrete (SCC) based on Nan Su mix design principles. First, the amount of aggregates required is determined, and the paste of binders is then filled into the voids of aggregates to ensure that the concrete thus obtained has flowability, self-compacting ability and other desired SCC properties. The amount of aggregates, binders and mixing water, as well as type and dosage of superplasticizer (SP) to be used are the major factors influencing the properties of SCC. Slump flow, V-funnel, L-flow, U-box and compressive strength tests were carried out to examine the performance of SCC, and the results indicate that the Nan Su method could produce successfully SCC of high strength. Based on Nan Su mix design method, material quantities such as powder content ( Cement + Pozzolan ), fine aggregate, coarse aggregate, water and dosages of SP and VMA,  required for 1 cu.m,  are evaluated for High strength grade (M80) of Self Compacting Concrete (SCC) are estimated. Final quantities, of M80 grade SCC mix, is assumed after several trial mixes on material quantities computed using Nan Su mix design method subjected to satisfaction of EFNARC flow properties. 

scholarly journals Performance Evaluation of High-Strength High-Volume Fly Ash Concrete

2019 ◽  
Vol 8 (3) ◽  
pp. 5990-5994 ◽  
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
High Volume ◽  
Absorption Capacity ◽  
Strength Gain ◽  
Fly Ash Concrete ◽  
High Volume Fly Ash

In the present study, high strength high volume fly ash concrete of M70 grade is developed and its durability properties such as water absorption capacity, porosity, and sorptivityare ascertained. It was found that high volume fly ash does not yield high strength so silica fume is added for early strength gain and for later strength gain lime required for complete pozzolonic action is added to achieve high performance concrete. In this study after testing for various combinations of quaternary blended concrete it was reported that 30% cement +70% fly ash as total powder achieves high strength of nearly 70 MPa, when silica fume of 10% by weight of powder and 30% of lime by weight of powder are added to the total powder content. The high strength high volume concrete developed with this optimum quantities of quaternary blends will be evaluated for the performance.It was found that water absorbtion in high strength high volume fly ash concrete reduced by nearly 85% and porosity is reduced by 34%.

scholarly journals Study of the Physical Behavior of a New Composite Material Based on Fly Ash from the Combustion of Coal in an Ultra-Supercritical Thermal Power Plant

2021 ◽  
Vol 5 (6) ◽  
pp. 151
Author(s):  
Mustapha El Kanzaoui ◽  
Chouaib Ennawaoui ◽  
Saleh Eladaoui ◽  
Abdelowahed Hajjaji ◽  
Abdellah Guenbour ◽  
...  
Keyword(s):  
Composite Material ◽  
Fly Ash ◽  
Power Plant ◽  
High Performance ◽  
Thermal Power ◽  
Recovery Process ◽  
Industrial Wastes ◽  
Raw Material ◽  
Polymerization Reaction ◽  
High Performance Composite

Given the amount of industrial waste produced and collected in the world today, a recycling and recovery process is needed. The study carried out on this subject focuses on the valorization of one of these industrial wastes, namely the fly ash produced by an ultra-supercritical coal power plant. This paper describes the use and recovery of fly ash as a high percentage reinforcement for the development of a new high-performance composite material for use in various fields. The raw material, fly ash, comes from the staged combustion of coal, which occurs in the furnace of an ultra-supercritical boiler of a coal-fired power plant. Mechanical compression, thermal conductivity, and erosion tests are used to study the mechanical, thermal, and erosion behavior of this new composite material. The mineralogical and textural analyses of samples were characterized using Scanning Electron Microscopy (SEM). SEM confirmed the formation of a new composite by a polymerization reaction. The results obtained are very remarkable, with a high Young’s modulus and a criterion of insulation, which approves the presence of a potential to be exploited in the different fields of materials. In conclusion, the composite material presented in this study has great potential for building material and could represent interesting candidates for the smart city.

Autogenous Volume Deformation and Creep Properties Analysis of C60 High Performance Concrete and C60 High Strength Concrete

2013 ◽  
Vol 639-640 ◽  
pp. 364-367 ◽  
Author(s):  
Xiao Bo Chen ◽  
Jian Yin ◽  
Wei Min Song
Keyword(s):  
Fly Ash ◽  
High Strength Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Engineering Practice ◽  
Volume Deformation ◽  
Creep Properties ◽  
Strength Concrete ◽  
Creep Coefficient

Based on engineering practice, autogenous volume deformation and creep properties of C60 high performance concrete(C60 HPC) and C60 high strength concrete(C60 HSC) were evaluated in the study. The results showed that the cement partly-replaced with fly ash could significantly decrease the creep deformation, creep coefficient and creep degree. In comparison with C60 HSC, the creep coefficient and creep degree of C60 HPC were decreased 17.9％and15.8％ in 28 days, 22.9% and 21.0% in 270 days. For C60 HPC and C60 HSC at the same age, autogenous volume deformation of C60 HPC is greater than that of C60 HSC, but they were both less than 80×10-6 , and the autogenous volume deformation was basically completed in 7 days.

High Performance Concrete with Ternary Binders

2018 ◽  
Vol 761 ◽  
pp. 120-123 ◽  
Author(s):  
Vlastimil Bílek ◽  
David Pytlík ◽  
Marketa Bambuchova
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Silica Fume ◽  
High Performance ◽  
Ordinary Portland Cement ◽  
High Performance Concrete ◽  
Fresh Concrete ◽  
Binder Ratio ◽  
Water To Binder Ratio ◽  
Condensed Silica Fume

Use a ternary binder for production of a high performance concrete with a compressive strengths between 120 and 170 MPa is presented. The water to binder ratio of the concrete is 0.225 and the binder is composed of Ordinary Portland Cement (OPC), condensed silica fume (CSF), ground limestone (L), fly ash (FA) and metakaoline (MK). The dosage of (M + CSF) is kept at a constant level for a better workability of fresh concrete. Different workability, flexural and compressive strengths were obtained for concretes with a constant cement and a metakaoline dosage, and for a constant dosage (FA + L) but a different ratio FA / L. An optimum composition was found and concretes for other tests were designed using this composition.

scholarly journals Strength Characteristics of High Strength Concrete (HSC) with and without Coarse Aggregate

2019 ◽  
Vol 9 (2) ◽  
pp. 4701-4704
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Mechanical Characteristics ◽  
Coarse Aggregate ◽  
High Strength ◽  
Set Up

This paper aimed to investigate the mechanical characteristics of HSC of M60 concrete adding 25% of fly ash to cement and sand and percentage variations of silica fumes 0%,5% and 10% to cement with varying sizes of 10mm,6mm,2mm and powder of granite aggregate with w/c of 0.32. Specimens are tested for compressive strength using 10cm X 10cmX10cm cubes for 7,14,28 days flexural strength was determined by using 10cmX10cmX50cm beam specimens at 28 days and 15cm diameter and 30cm height cylinder specimens at 28 days using super plasticizers of conplast 430 as a water reducing agent. In this paper the experimental set up is made to study the mechanical properties of HSC with and without coarse aggregate with varying sizes as 10mm, 6mm, 2mm and powder. Similarly, the effect of silica fume on HSC by varying its percentages as 0%, 5% and 10% in the mix studied. For all mixes 25% extra fly ash has been added for cement and sand.

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