Advancements in Properties of Cements Containing Pulverised Fly Ash and Nanomaterials by Blending and Ultrasonication Method (Review- Part II)

2019 ◽  
Vol 24 ◽  
pp. 37-44 ◽  
Author(s):  
Mehmet Serkan Kirgiz
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Review Paper ◽  
Setting Time ◽  
Heat Of Hydration ◽  
Strength Gain ◽  
Hydration Properties ◽  
Setting Times ◽  
Current Article

The second part of this review paper will explain Hydration properties of Portland pulverised fly ash cement section, Effect of nanomaterial on setting–time section, Effect of nanomaterial on heat of hydration section, Strength gain mechanisms for hardened Portland pulverised fly ash cement paste and mortar section, Effect of nanomaterial on compressive strength section, Effect of nanomaterial on flexural strength (Bending) section, and Conclusion section. Experiments reported include the setting–times, the heat of hydration, the compressive strength gain, and the flexural strength gain in the current article. According to the result, nanoparticles, especially the GNP, increase the heat of hydration of cement, and accelerate the time of setting evidently, both initial and final setting-time. The most effective nanoparticle on early compressive strength gain and flexural strength gain is the GNP. The article also points the effects of the nanoparticles on the strength gain of cement comprehensively. Consequently, the prominent cement technology can use the nanoparticles dispersed in liquid by ultrasonication method to increase the properties of cement based materials effectively.

Advancements in Properties of Cement Containing Pulverised Fly Ash and Nanomaterials by Blending and Ultrasonication Method (Review - Part I)

2018 ◽  
Vol 19 ◽  
pp. 1-11 ◽  
Author(s):  
Mehmet Serkan Kirgiz
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Water Demand ◽  
Review Paper ◽  
Setting Time ◽  
Heat Of Hydration ◽  
Strength Gain ◽  
Hydration Properties ◽  
Carbon Nano Tube

This review research aims to discuss the results obtained researches on cement containing pure cement, pulverised fly ash, and nanoparticles, in order for eliminating negative side effects underlie the substitution of by–products for pure Portland cement. Nanoparticles (NP) used in these researches are nanoTiO2, nanoSiO2, nanoCaCO3, fibers of carbon nano tube (CNT), nanolimestone (nanoCaCO3), nanoZrO2, nanoclays, and nanometakaolin (nMK) for improving properties of cement systems. Published manuscripts explains two methods regarding on the usage of nanoparticles for cement system: blending and ultrasonication for dispersion of nanoparticles. However, differences between blending and ultrasonication methods suggested by various researchers are also discussed. Experiments reported these papers include the water demand, the density, the setting–times, the heat of hydration, the fluidity, the compressive strength and the flexural strength. According to these results, nanoparticles increase the water demand and heat of hydration of cement; it decreases the density and fluidity for cement mortars, evidently. The most effective nanoparticles on early compressive and flexural strengths are fibers of carbon nano tube and nanoCaCO3. These papers also point effects of these nanoparticles on the strength gain of cement. This review paper inform us until Effect of nanomaterial on water demand and density section in this Part I. Second part of this review paper will explain Hydration properties of Portland pulverised fly ash cement section, Effect of nanomaterial on setting–time section, Effect of nanomaterial on heat of hydration section, Strength gain mechanisms for hardened Portland pulverised fly ash cement paste and mortar section, Effect of nanomaterial on compressive strength section, Effect of nanomaterial on flexural strength (Bending) section, and Conclusion section.

scholarly journals Strength Development and Thermogravimetric Investigation of High-Volume Fly Ash Binders

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3344 ◽  
Author(s):  
Zhiyuan Zhou ◽  
Massoud Sofi ◽  
Elisa Lumantarna ◽  
Rackel San Nicolas ◽  
Gideon Hadi Kusuma ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Temperature Rise ◽  
Bound Water ◽  
High Volume ◽  
Heat Of Hydration ◽  
New Method ◽  
Hydration Properties ◽  
Adiabatic Temperature Rise ◽  
High Volume Fly Ash

To address sustainability issues by facilitating the use of high-volume fly ash (HVFA) concrete in industry, this paper investigates the early age hydration properties of HVFA binders in concrete and the correlation between hydration properties and compressive strengths of the cement pastes. A new method of calculating the chemically bound water of HVFA binders was used and validated. Fly ash (FA) types used in this study were sourced from Indonesia and Australia for comparison. The water to binder (w/b) ratio was 0.4 and FA replacement levels were 40%, 50% and 60% by weight. Isothermal calorimetry tests were conducted to study the heat of hydration which was further converted to the adiabatic temperature rise. Thermo-gravimetric analysis (TGA) was employed to explore the chemically bound water (WB) of the binders. The results showed that Australian FA pastes had higher heat of hydration, adiabatic temperature rise, WB and compressive strength compared to Indonesian FA pastes. The new method of calculating chemically bound water can be successfully applied to HVFA binders. Linear correlation could be found between the WB and compressive strength.

scholarly journals Effect of fly ash on physical and mechanical properties of mortar

2019 ◽  
Vol 17 (6) ◽  
pp. 35
Author(s):  
Vu-An Tran
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Water Absorption ◽  
Thermal Power ◽  
Setting Time ◽  
Physical And Mechanical Properties ◽  
Flow Density ◽  
Control Specimen

This research investigates the physical and mechanical properties of mortar incorporating fly ash (FA), which is by-product of Duyen Hai thermal power plant. Six mixtures of mortar are produced with FA at level of 0%, 10%, 20%, 30%, 40%, and 50% (by volume) as cement replacement and at water-to-binder (W/B) of 0.5. The flow, density, compressive strength, flexural strength, and water absorption tests are made under relevant standard in this study. The results have shown that the higher FA content increases the flow of mortar but significantly decreases the density of mixtures. The water absorption and setting time increases as the samples incorporating FA. Compressive strength of specimen with 10% FA is approximately equal to control specimen at the 91-day age. The flexural strength of specimen ranges from 7.97 MPa to 8.94 MPa at the 91-day age with the best result for samples containing 10% and 20% FA.

scholarly journals Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
El-Sayed Negim ◽  
Latipa Kozhamzharova ◽  
Yeligbayeva Gulzhakhan ◽  
Jamal Khatib ◽  
Lyazzat Bekbayeva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
High Volume ◽  
Physicomechanical Properties ◽  
Partial Replacement ◽  
Setting Times ◽  
High Volume Fly Ash ◽  
Scanning Electron

This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

scholarly journals Circulation Fluidized Bed Combustion Fly Ash as Partial Replacement of Fine Aggregates in Roller Compacted Concrete

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4204 ◽  
Author(s):  
Wei-Ting Lin ◽  
Kae-Long Lin ◽  
Kailun Chen ◽  
Kinga Korniejenko ◽  
Marek Hebda ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Fluidized Bed ◽  
Setting Time ◽  
Unit Weight ◽  
Fluidized Bed Combustion ◽  
Sulfate Resistance ◽  
Roller Compacted Concrete ◽  
Fine Aggregates

Recently, many people around the world have been concerned with environmental protection and sustainability. The goal of various countries’ research has been focused on how to regenerate existing resources. Circulation fluidized bed combustion (CFBC) technology is one of the emerging combustion technologies for electricity generation and produces more than 800,000 tons of CFBC fly ash (CFA) per year for combustion. CFA has been widely applied in cement additive, new building materials and cement-based materials. The goal of this study was to discuss the engineering properties of roller-compacted concrete containing CFA. Test subjects included compressive strength, flexural strength, absorption, setting time, unit weight, sulfate resistance, SEM microscopic observations and XRD ingredient analysis. Test results indicate the following: (1) using CFA as a substitute of fine aggregates up to 10 wt.% would improve the development of later flexural strength; (2) the increases in pre-pressure would increase the compressive strength and unit weight and decrease absorption; (3) using CFA would reduce the initial setting time by 30%–60% and reduce the final setting time by 16%–20%; (4) using CFA would reduce the absorption; (5) using CFA would reduce the unit weight by 0.5%–2.8%, and the increases in pre-pressure would increase the unit weight by about 0.9%–2.1%; (6) CaO in CFA helps to improve sulfate resistance; (7) scanning electron microscopy (SEM) observation shows that the increases in pre-pressure would reduce the pores; and (8) X-ray diffraction (XRD) analysis shows that the inclusion of CFA would increase the content of Ca(OH)2 in concrete.

scholarly journals Investigation on the Compressive Strength and Time of Setting of Low-Calcium Fly Ash Geopolymer Paste Using Response Surface Methodology

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3461
Author(s):  
Pauline Rose J. Quiatchon ◽  
Ithan Jessemar Rebato Dollente ◽  
Anabel Balderama Abulencia ◽  
Roneh Glenn De Guzman Libre ◽  
Ma. Beatrice Diño Villoria ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Setting Time ◽  
Initial Setting Time ◽  
Alkali Activator ◽  
Setting Times ◽  
Confirmatory Tests ◽  
Initial Setting

Approximately 2.78 Mt of coal fly ash is produced in the Philippines, with a low utilization rate. Using fly ash-based geopolymer for construction will lessen the load sent to landfills and will result in lower GHG emissions compared to OPC. It is necessary to characterize the fly ash and optimize the geopolymer components to determine if it can replace OPC for in situ applications. The activator-to-precursor ratio, the water-to-solids ratio, and the sodium hydroxide-to-sodium silicate ratio were optimized using a randomized I-optimal design from the experimental results of 21 runs with five replicates, for a total of 105 specimens of 50 mm × 50 mm × 50 mm paste cubes. The engineering properties chosen as the optimization responses were the unconfined compressive strength (UCS), the initial setting time, and the final setting time. The samples were also ambient-cured with the outdoor temperature ranging from 30 °C to 35 °C and relative humidity of 50% ± 10% to simulate the on-site environment. Runs with high unconfined compressive strength (UCS) and short setting times were observed to have a low water-to-solids (W/S) ratio. All runs with a UCS greater than 20 MPa had a W/S ratio of 0.2, and the runs with the lowest UCS had a W/S of 0.4. The initial setting time for design mixes with a W/S ratio of 0.2 ranged from 8 to 105 min. Meanwhile, five out of seven design mixes with a W/S ratio of 0.4 took longer than 1440 min to set. Specimens with an alkali activator ratio (NaOH/WG) of 0.5 (1:2) and 0.4 (1:2.5) also had significantly lower setting times than those with an alkali activator ratio of 1. The RSM model was verified through confirmatory tests. The results of the confirmatory tests are agreeable, with deviations from the expected UCS ranging from 0 to 38.12%. The generated model is a reliable reference to estimate the UCS and setting time of low-calcium FA geopolymer paste for in situ applications.

Reaction Products in Fly Ash Concrete

1984 ◽  
Vol 43 ◽  
Author(s):  
Mark D. Baker ◽  
Joakim G. Laguros
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Calcium Hydroxide ◽  
Setting Time ◽  
Heat Of Hydration ◽  
Hydration Process ◽  
Reaction Products ◽  
Fly Ash Concrete ◽  
Xrd Studies ◽  
One Year

AbstractThe setting and strength gaining process of PC concrete containing Class C high lime fly ash were related to the reaction products identified using XRD and SEM. Four fly ash concrete mixes (20, 30, 40, and 50 percent replacement of cement by fly ash) and similar paste mixes were compared to control mixes for curing periods up to one year. Setting time and early compressive strength were adversely affected by the addition of fly ash. Beyond one week all of the fly ash concrete mixes gained strength at a faster rate than the corresponding control mixes. XRD studies suggest that the retardation mechanism may be associated with the high levels of ettringite formed early in the hydration process and its conversion to monosulfoaluminate. A decrease in the level of calcium hydroxide, typical of pozzolanic activity, was not in evidence. SEM micrographs of fly ash spheres in concrete at the various stages of hydration reveal an intricate crystal framework. A simple heat of hydration test is presented which helps explain the strength gains observed.

scholarly journals Characteristics of Waste Iron Powder as a Fine Filler in a High-Calcium Fly Ash Geopolymer

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2515
Author(s):  
Toon Nongnuang ◽  
Peerapong Jitsangiam ◽  
Ubolluk Rattanasak ◽  
Weerachart Tangchirapat ◽  
Teewara Suwan ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Iron Powder ◽  
Construction Material ◽  
Setting Time ◽  
Bottom Ash ◽  
Curing Process ◽  
Heat Curing ◽  
High Calcium

Geopolymer (GP) has been applied as an environmentally-friendly construction material in recent years. Many pozzolanic wastes, such as fly ash (FA) and bottom ash, are commonly used as source materials for synthesizing geopolymer. Nonetheless, many non-pozzolanic wastes are often applied in the field of civil engineering, including waste iron powder (WIP). WIPs are massively produced as by-products from iron and steel industries, and the production rate increases every year. As an iron-based material, WIP has properties of heat induction and restoration, which can enhance the heat curing process of GP. Therefore, this study aimed to utilize WIP in high-calcium FA geopolymer to develop a new type of geopolymer and examine its properties compared to the conventional geopolymer. Scanning electron microscopy and X-ray diffraction were performed on the geopolymers. Mechanical properties, including compressive strength and flexural strength, were also determined. In addition, setting time and temperature monitoring during the heat curing process were carried out. The results indicated that the addition of WIP in FA geopolymer decreased the compressive strength, owing to the formation of tetrahydroxoferrate (II) sodium or Na2[Fe(OH)4]. However, a significant increase in the flexural strength of GP with WIP addition was detected. A flexural strength of 8.5 MPa was achieved by a 28-day sample with 20% of WIP addition, nearly three times higher than that of control.

scholarly journals Geopolymer Concrete under Ambient Curing

2021 ◽  
Author(s):  
M. Indhumathi Anbarasan ◽  
S.R. Sanjaiyan ◽  
S. Nagan Soundarapandiyan
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Setting Time ◽  
Geopolymer Concrete ◽  
Split Tensile Strength ◽  
Carbon Footprints ◽  
Curing Conditions ◽  
Ambient Curing

Geopolymer concrete (GPC) has significant potential as a more sustainable alternative for ordinary Portland cement concrete. GPC had been introduced to reduce carbon footprints and thereby safeguarding environment. This emerging eco friendly construction product finds majority of its application in precast and prefabricated structures due to the special curing conditions required. Sustained research efforts are being taken to make the product suitable for in situ applications. The developed technology will certainly address the issues of huge energy consumption as well reduce water use which is becoming scarce nowadays. Ground Granulated Blast Furnace Slag (GGBS) a by-product of iron industries in combination with fly ash has proved to give enhanced strength, durability as well reduced setting time. This study investigates the effect of GGBS as partial replacement of fly ash in the manufacture of GPC. Cube and cylindrical specimens were cast and subjected to ambient curing as well to alternate wetting-drying cycles. The 28 day compressive strength, split tensile strength, flexural strength and density of GPC specimens were found. The study revealed increase in compressive strength, split tensile strength, density as well flexural strength up to 40 percent replacement of fly ash by GGBS.

Development of Geopolymer Utilizing Inorganic Waste Materials

2014 ◽  
Vol 896 ◽  
pp. 553-556 ◽  
Author(s):  
Tjokorde Walmiki Samadhi ◽  
Pambudi Pajar Pratama ◽  
Nurhidayati Muan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
Factorial Experiment ◽  
Curing Temperature ◽  
Engineering Properties ◽  
Waste Materials ◽  
Setting Times ◽  
Wide Range ◽  
Inorganic Waste

Geopolymers, which are produced by the reaction between aluminosilicate solid precursors and concentrated alkali solutions, is an environmentally attractive construction material due to its much smaller carbon footprint compared to ordinary Portland cement (OPC), and its ability to consume a wide range of solid inorganic waste materials. This work describes the synthesis of geopolymers utilizing local aluminosilicate materials and the evaluation of several key engineering properties of the geopolymer product as a construction cement. A simple 22factorial experiment is undertaken to measure the effect of types aluminosilicate solids (metakaolin produced by calcining a Belitung kaolin at 750 °C, and coal fly ash from an East Java baseload powerplant) and alkali activators (NaOH and KOH solutions) on the initial and final setting time of the geopolymer cement mortar. All geopolymer mortar samples exhibit longer setting times compared to OPC mortars. Statistical analysis indicates that KOH produces faster initial setting than NaOH, while fly ash produces faster setting times compared to metakaolin. A 23factorial experiment is conducted subsequently, adding curing temperature (60 and 80 °C) to the experimental factors. The key engineering property measured in the second experiment is the compressive strength of geopolymer mortars. ANOVA treatment of the measured data indicates that all three experimental factors significantly impacts the compressive strength. Consistent with the preceding experiment, the use of fly ash and KOH significantly increases the strength of the geopolymer mortar. Higher curing temperature is also found to increase the strength. The use of metakaolin as geopolymer precursor produces compressive strength approximately 50% than that of the OPC mortar, while fly ash produces a geopolymer mortar strength that is at least as good as OPC.

Sign in / Sign up

Export Citation Format

Share Document