Characteristics of a Fly Ash-Based Geopolymer Cured in Microwave Oven

2020 ◽  
Vol 850 ◽  
pp. 63-69
Author(s):  
Quang Minh Do ◽  
Phuong Minh Ngo ◽  
Hoc Thang Nguyen
Keyword(s):  
Fly Ash ◽  
High Strength ◽  
Microwave Oven ◽  
Engineering Properties ◽  
Microstructural Characteristics ◽  
High Pressure And Temperature ◽  
High Chemical Resistance ◽  
Alkaline Conditions ◽  
Alumino Silicate ◽  
A New Technique

Geopolymer is known as an alkaline alumino-silicate material that has many potential advantages to replace for cement-based materials. Geopolymer is a green material with low or non-CO2 emission technology, high strength and heat resistance, high chemical resistance, and low energy production. Geopolymer has synthesized from activated alumino-silicate resources in high alkaline conditions. After formed, the geopolymer samples are cured in different conditions such as room temperature, drying oven temperature (from 40°C to 150°C), high pressure and temperature conditions of autoclave equipment. In this study, the paper would like to introduce a new technique for curing the specimens. The geopolymer samples were cured in a microwave oven set by various regimes of curing time. After cured in microwave conditions, the samples were tested for engineering properties such as compressive strength (MPa), volumetric weight (kg/m3), and water absorption (kg/m3). This technology is a useful solution because of saving time for curing the geopolymer specimens in comparison with others (normally, it takes time for curing in 28 days). Microstructural characteristics of the fly ash-based geopolymer were analyzed and evaluated using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR).

Geopolymer Sourced with Fly Ash and Industrial Aluminum Waste for Sustainable Materials

2020 ◽  
pp. 676-696
Author(s):  
Sujitra Onutai ◽  
Sirithan Jiemsirilers ◽  
Takaomi Kobayashi
Keyword(s):  
Fly Ash ◽  
Industrial Waste ◽  
Raw Materials ◽  
Acid Resistance ◽  
High Strength ◽  
Microwave Oven ◽  
Silicate Material ◽  
High Acid ◽  
Alumino Silicate ◽  
Geopolymer Cement

Geopolymer is alumino-silicate material which can apply for many applications due to that geopolymers have several attractive properties of high strength, low permeability, high acid resistance, hazardous materials, and immobilization of toxic materials. This chapter presents synthesis of the dense and the porous structures of geopolymer by using fly ash and industrial waste as the raw materials. Aluminum hydroxide waste (Al-waste) and fly ash (FA) were used to synthesis the dense geopolymers for cement materials. The Al-waste based geopolymer influenced the geopolymer strength, when sodium hydroxide (NaOH) concentration was changed at different curing temperatures. As preliminary microwave oven was exposed in the lower NaOH paste of geopolymer, the successful synthesis of geopolymer cement was obtained. In addition, porous fly ash geopolymers was achieved using a household microwave oven. The geopolymer paste was cured within 1 min by using a microwave oven at different output power. Porous geopolymers were formed immediately as ued at 850 W power of the microwave oven.

Geopolymer Sourced with Fly Ash and Industrial Aluminum Waste for Sustainable Materials

2017 ◽  
pp. 165-185
Author(s):  
Sujitra Onutai ◽  
Sirithan Jiemsirilers ◽  
Takaomi Kobayashi
Keyword(s):  
Fly Ash ◽  
Industrial Waste ◽  
Raw Materials ◽  
Acid Resistance ◽  
High Strength ◽  
Microwave Oven ◽  
Silicate Material ◽  
High Acid ◽  
Alumino Silicate ◽  
Geopolymer Cement

Geopolymer is alumino-silicate material which can apply for many applications due to that geopolymers have several attractive properties of high strength, low permeability, high acid resistance, hazardous materials, and immobilization of toxic materials. This chapter presents synthesis of the dense and the porous structures of geopolymer by using fly ash and industrial waste as the raw materials. Aluminum hydroxide waste (Al-waste) and fly ash (FA) were used to synthesis the dense geopolymers for cement materials. The Al-waste based geopolymer influenced the geopolymer strength, when sodium hydroxide (NaOH) concentration was changed at different curing temperatures. As preliminary microwave oven was exposed in the lower NaOH paste of geopolymer, the successful synthesis of geopolymer cement was obtained. In addition, porous fly ash geopolymers was achieved using a household microwave oven. The geopolymer paste was cured within 1 min by using a microwave oven at different output power. Porous geopolymers were formed immediately as ued at 850 W power of the microwave oven.

Fly Ash-Based Geopolymer: Green Material in Carbon-Constrained Society

2021 ◽  
Vol 321 ◽  
pp. 65-71
Author(s):  
Hoc Thang Nguyen ◽  
Phong Thanh Dang
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Thermal Power ◽  
Bottom Ash ◽  
Coal Ash ◽  
Raw Material ◽  
Engineering Properties ◽  
Gravimetric Analysis ◽  
Green Materials ◽  
Alumino Silicate

Climate change is recognized as a global problem and even the industrial and construction sectors are trying to reduce the green-house gas emissions, especially on CO2 emissions. In Vietnam, the coal-fired thermal power plants are discharging millions of tons of CO2 and coal ash annually. This coal ash is comprised of about 80% of fly ash and the rest is bottom ash. This study would like to introduce one of the potential solutions in a carbon-constrained society that would not only manage the fly ash but also utilized this as raw material for green materials through geopolymerization. The geopolymer-based material has lower energy consumption, minimal CO2 emissions and lower production cost as it valorizes industrial waste. The fly ash containing high alumino-silicate resources from a coal-fired power plant in Vietnam was mixed with sodium silicate and sodium hydroxide solutions to obtain the geopolymeric pastes. The pastes were molded in 10x10x20cm molds and then cured at room temperature for 28 days. The 28-day geopolymer specimens were carried out to test for engineering properties such as compressive strength (MPa), volumetric weight (kg/m3), and water absorption (kg/m3). The microstructure analysis was also conducted for this eco-friendly materials using X ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscope (SEM), Differential Thermal Analysis - Thermal Gravimetric Analysis (DTA-TGA).

Microstructure Study on Optimization of High Strength Fly Ash Based Geopolymer

2012 ◽  
Vol 476-478 ◽  
pp. 2173-2180 ◽  
Author(s):  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Mohammed Binhussain ◽  
Ismail Khairul Nizar ◽  
Rafiza Abd Razak ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
High Strength ◽  
Curing Temperature ◽  
Mix Design ◽  
Dense Matrix ◽  
Microstructural Characteristics ◽  
Naoh Solution ◽  
Alkaline Activator

The compressive strength and microstructural characteristics of fly ash based geopolymer with alkaline activator solution were investigated. The sodium hydroxide and sodium silicate were mixed together to form an alkaline activator. Three parameters including NaOH molarity, mix design (fly ash/alkaline activator ratio and Na2SiO3/NaOH ratio), and curing temperature were examined. The maximum strength of 71 MPa was obtained when the NaOH solution of 12M, fly ash/alkaline activator of 2.0, Na2SiO3/NaOH of 2.5 and curing temperature of 60°C were used at 7th days of testing. The results of SEM indicated that for geopolymer with highest strength, the structure was dense matrix and contains less unreacted fly ash with alkaline activator

scholarly journals Strength, Physicochemical and Morphological Characteristics of Fly Ash Stabilized Black Cotton Soil

2019 ◽  
Vol 8 (2) ◽  
pp. 616-623
Keyword(s):  
Fly Ash ◽  
Research Work ◽  
Morphological Characteristics ◽  
Engineering Properties ◽  
Black Cotton Soil ◽  
Experimental Program ◽  
Swelling Properties ◽  
Curing Period ◽  
Shrinkage And Swelling ◽  
Alumino Silicate

Black Cotton (BC) soil is one of the problematic soil deposits in India. These soils are problematic due to their poor engineering properties and high shrinkage and swelling properties due to high affinity to water. This paper, explore stabilization of Black cotton soil having poor strength characteristic and high shrinkage and swelling characteristic, with Class F Fly Ash (FA) to verify its scope for use as soil sub-base construction material. Fly ash is a good soil stabilizing additive in alone or along with other additives. It improves the index and engineering properties of Black cotton soil as verified from previous research work. In this research work, a Laboratory experimental program was planned with Fly ash, variation from 0% to 50% and humid curing period varies from 0 to 28 days. In the first stage of the experiment, Atterberg’s limits and compaction test have performed on Black cotton soil with all mixture and found their respective Optimum Moisture Content (OMC) and Maximum Dry Densities (MDD). In the second stage of the experiment, UCS and CBR tests were carried out for immediate, 7, 14, 28 and 45 days curing periods. The Atterberg’s limits, OMC, MDD, UCS, and CBR of Fly ash stabilized Black cotton found much satisfactory at 20% FA and 28 days curing period. CBR and UCS value get increments of 77.91% and 83.45% respectively. From the physicochemical analysis through X-Ray Diffraction (XRD) and Scanning of Electron Microscope (SEM), it was noticed That enhancement of strength is due to the pozzolanic reaction which causes the formation of new crystalline mineral of Alumino-Silicate-Hydrates (ASH) and Calcium- Alumino-Silicate-Hydrates(CASH) in void space of the matrix

Relationships Between Permeability And Microstructural Characteristics Of Fly Ash Mortars

1988 ◽  
Vol 137 ◽  
Author(s):  
Robert L. Day ◽  
Ladislav Konecny
Keyword(s):  
Fly Ash ◽  
Oxygen Permeability ◽  
Mercury Porosimetry ◽  
Chloride Ion ◽  
Engineering Properties ◽  
Partial Replacement ◽  
Permeability Test ◽  
Strength Gain ◽  
Microstructural Characteristics ◽  
Water Oxygen

AbstractThe paper describes research to evaluate permeability and the microstructure of mortars containing fly ash as a partial replacement for cement. The replacement levels of cement by fly ash were 35 and 50% by volume and 50% by weight; effectiveness of mortars made with four types of fly ash at two water/cement ratios, 0.47 and 0.65, were assessed. Three types of permeability measurements were made: (a) water permeability, (b) oxygen permeability and (c) permeability to chloride ion by the 6-hour rapid permeability test. Measurements were performed at 7, 28 and 160 days age. Strength gain in the mortar mixes was also monitored. In an attempt to explain trends observed in permeability, the pore structures of oven-dried and solventexchanged specimens were examined by mercury porosimetry. Mortars manufactured with fly ash displayed superior engineering properties when compared to the control mortars. Significant correlations were found among measurements of permeability by water, oxygen and chloride ion. Relationships were also observed between permeability and some microstructural indicators, especially the volume of mercury intruded up to a pressure of 41 MPa (6000 psi).

Relationships Between Permeability and Microstructural Characteristics of Fly Ash Mortars

1988 ◽  
Vol 136 ◽  
Author(s):  
Robert L. Day ◽  
Ladislav Konecny
Keyword(s):  
Fly Ash ◽  
Oxygen Permeability ◽  
Mercury Porosimetry ◽  
Chloride Ion ◽  
Engineering Properties ◽  
Partial Replacement ◽  
Permeability Test ◽  
Strength Gain ◽  
Microstructural Characteristics ◽  
Water Oxygen

ABSTRACTThe paper describes research to evaluate permeability and the microstructure of mortars containing fly ash as a partial replacement for cement. The replacement levels of cement by fly ash were 35 and 50% by volume and 50% by weight; effectiveness of mortars made with four types of fly ash at two water/cement ratios, 0.47 and 0.65, were assessed. Three types of permeability measurements were made: (a) water permeability, (b) oxygen permeability and (c) permeability to chloride ion by the 6-hour rapid permeability test. Measurements were performed at 7, 28 and 160 days age. Strength gain in the mortar mixes was also monitored. In an attempt to explain trends observed in permeability, the pore structures of oven-dried and solventexchanged specimens were examined by mercury porosimetry. Mortars manufactured with fly ash displayed superior engineering properties when compared to the control mortars. Significant correlations were found among measurements of permeability by water, oxygen and chloride ion. Relationships were also observed between permeability and some microstructural indicators, especially the volume of mercury intruded up to a pressure of 41 MPa (6000 psi).

scholarly journals Effects of Micro Silica & Flyash on Strength & Durability Parameters of High Strength Concrete

2021 ◽  
Vol 9 (VI) ◽  
pp. 4650-4653
Author(s):  
Hiral Karavadra
Keyword(s):  
Fly Ash ◽  
High Strength Concrete ◽  
High Strength ◽  
Engineering Properties ◽  
Original Form ◽  
Nano Silica ◽  
Acid Attack ◽  
Strength Concrete ◽  
Micro Silica ◽  
Durability Of Concrete

High strength concrete is a term used to describe concrete with special properties not attributed to normal concrete. High-performance means that the concrete has one or more of the following properties: low shrinkage, low permeability, a high modulus of elasticity, or high strength. The application of nanotechnology in concrete has added a new dimension to the efforts to improve properties of High strength concrete. Nano materials, by virtue of their very small particle size can affect the concrete properties by altering the microstructure. Concrete can deteriorate for a variety of reasons, and concrete damage is often as result of combination of factors. This causes stresses in the concrete, which can eventually have resulted in cracking, delamination, and spalling. Concrete resists weathering action, chemical attack, and abrasion while maintaining its desired engineering properties throughout its lifespan. Different concretes require different degrees of durability depending on the exposure of environment and the properties desired. Durable concrete will retain its original form, quality and serviceability when exposed to its environment. The main characteristics influencing the durability of concrete is its permeability to the ingress of water, oxygen, carbon dioxide, chloride, sulphate and other deleterious substances. It became necessary to impart knowledge about durability of concrete and factors affecting durability to the society, as the wide use of concrete as a material in the constructions. This study concerns with the use of Nano silica of size 12 nm in M60 grade of concrete to improve the compressive strength of concrete and study on various durability parameters of High strength concrete. An experimental investigation is planned to carry out with different amount of Fly ash as 15% ,20%, 25%,30% and Micro silica as 5.5%,7%,8.5%,10% in concrete by weight of concrete. have been planned to carry out are workability, compressive test, flexural test, split tensile test. To study durability parameters of High strength concrete with nano silica Rapid chloride penetration test (RCPT), Water Sorptivity test, Acid attack test, Sulphate attack test are conduct. In this study it was observed that t the durability, strength and workability are increase as the percentage of fly ash & micro silica increses

Study on Strength Development of High Strength Concrete Containing Alccofine and Fly-Ash

2012 ◽  
Vol 2 (3) ◽  
pp. 102-104 ◽  
Author(s):  
Suthar Sunil B ◽  
◽  
Dr. (Smt.) B. K. Shah Dr. (Smt.) B. K. Shah
Keyword(s):  
Fly Ash ◽  
High Strength Concrete ◽  
High Strength ◽  
Strength Development ◽  
Strength Concrete
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