Setting time and compression strength of low-calcium fly ash geopolymer paste with non-calcined red soil substitution in ambient curing

Grouting fill is one of the main methods of coal gob treatment. The grouting properties directly affect the effect of grouting treatment. Cement-fly ash grout is widely used in the treatment of coal gob. But in many gob grouting fill projects, due to the lack of fly ash, we need to look for other low-cost grouting materials. Study was made through laboratory experiment on the properties of cement-coal gangue materials used for the gob grouting. In this paper, the correlation of water-solid ratio, cement content, admixture, concretion compression strength, setting time, viscosity, water segregation rate and hardening rate is discussed in the case of use of large gangue content cement. The test results show that compared with the grout not go through the activation process, the blended cement grout mixed with coal gangue powder activated by low temperature and mechanical crushing has high concretion compression strength. Water glass has a great effect on the viscosity, initial setting time and final setting time, which can be used to adjust the grout properties to accommodate grouting environment requirements. This grout has the advantage of wide range sources of raw materials, and can be used to solve the lack of fly ash and gangue resource utilization problems.

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Early Age Properties of Low-calcium Fly Ash Geopolymer Concrete Suitable for Ambient Curing

Procedia Engineering ◽

10.1016/j.proeng.2015.11.077 ◽

2015 ◽

Vol 125 ◽

pp. 601-607 ◽

Cited By ~ 51

Author(s):

Pradip Nath ◽

Prabir Kumar Sarker ◽

Vijaya B. Rangan

Keyword(s):

Fly Ash ◽

Early Age ◽

Geopolymer Concrete ◽

Low Calcium ◽

Ambient Curing

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Factors influencing strength and setting time of fly ash based-geopolymer paste

MATEC Web of Conferences ◽

10.1051/matecconf/201713801010 ◽

2017 ◽

Vol 138 ◽

pp. 01010 ◽

Cited By ~ 7

Author(s):

Adhitya Leonard Wijaya ◽

Januarti Jaya Ekaputri ◽

Triwulan

Keyword(s):

Fly Ash ◽

Setting Time ◽

Factors Influencing ◽

Geopolymer Paste

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The Investigation on Setting Time and Strength of High Calcium Fly Ash Based Geopolymer

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.881.158 ◽

2018 ◽

Vol 881 ◽

pp. 158-164 ◽

Cited By ~ 4

Author(s):

Remigildus Cornelis ◽

Henricus Priyosulistyo ◽

Iman Satyarno ◽

Rochmadi

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Setting Time ◽

Solid Ratio ◽

Synthesis Parameters ◽

Heat Curing ◽

High Calcium ◽

High Calcium Fly Ash ◽

Ambient Curing

Fly ash based geopolymer normally gets the optimum strength by heat curing. This is considered as a hindrance to in-situ applications. Therefore, development of fly ash based geopolymer that suitable for ambient curing will widen the application to the concrete structure. This paper reports the results of an experimental study on setting time and development of compressive strength of class C fly ash based geopolymer paste produced in ambient curing condition. The main synthesis parameters such as water to the geopolymer solid ratio, alkali to cementitious ratio and molarity of NaOH were varied to understand their individual effect on setting time and the mechanical properties of the resulting geopolymer. The results suggested that generally the setting time increased with the NaOH molarity and the compressive strength of 59 MPa was obtained for geopolymer mixture cured at ambient temperature for 28 days with alkali to a cementitious ratio of 0.35 and 10 M NaOH. The results will be useful for developing the knowledge of the use of high calcium fly ash in producing geopolymer. This would be beneficial to the understanding the future applications of this material as new binding material.

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Investigation on the Degree of Reaction and Strength Performance of Fly Ash Based Geopolymer Binder with Alternative Chemical Reagents

Materials Science Forum ◽

10.4028/www.scientific.net/msf.803.115 ◽

2014 ◽

Vol 803 ◽

pp. 115-119

Author(s):

Norbaizurah Rahman ◽

Andri Kusbiantoro

Keyword(s):

Fly Ash ◽

Citric Acid ◽

Sodium Nitrate ◽

Setting Time ◽

Strength Development ◽

Degree Of Hydration ◽

Degree Of Reaction ◽

High Calcium ◽

Geopolymer Binder ◽

Geopolymer Paste

The existence of high calcium contents in fly ash will contribute to the rapid stiffening and low workability of geopolymer paste. This study reports the feasibility of sodium nitrate and citric acid as the alternative admixtures for geopolymer binder. The effects of sodium nitrate and citric acid were independently evaluated at 0.5%, 1.5% and 2.5% of fly ash weight in geopolymer mixture. The effect of these admixtures on fresh geopolymer characteristic was evaluated through series of setting time and flow table workability tests, while degree of hydration, compressive strength and porosity tests were conducted to provide fundamental information on the hardened properties of geopolymer paste. Based on the result of degree of reaction, the inclusion of sodium nitrate in fly ash based geopolymer will increase the level of degree of hydration. Nevertheless, this result is in contrast with citric acid inclusion where degree of hydration decreased along with the increasing dosage of citric acid in the mixture. Strength development of geopolymer paste, particularly during the early age, appears to be affected by various geopolymerization rate presented by these admixtures.

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Geopolymer Concrete under Ambient Curing

10.5772/intechopen.97541 ◽

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.

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Influence of Glass and Limestone Powders in High Calcium Fly Ash Geopolymer Paste on Compressive Strength and Microstructure

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.801.397 ◽

2019 ◽

Vol 801 ◽

pp. 397-403

Author(s):

Pattanapong Topark-Ngarm ◽

Tawatchai Tho-In ◽

Vanchai Sata ◽

Prinya Chindaprasirt ◽

Trinh Cao

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Glass Powder ◽

Sodium Hydroxide Solution ◽

Setting Time ◽

Limestone Powder ◽

Hydration Reaction ◽

High Calcium ◽

High Calcium Fly Ash ◽

Geopolymer Paste

The effects of replacing high calcium fly ash with containment glass powder and limestone powder in the geopolymer are investigated in this paper. The high calcium fly ash was replaced by either glass powder or limestone powder at 20% and 40% by weight. The geopolymer paste was tested for setting time and compressive strength and evaluated of its microstructure on SEM, XRD, FTIR, and MIP. The results indicated that the setting time of geopolymer paste was increased with the replacement of glass powder and reduced by replacement of limestone powder. The compressive strengths were generally higher than those of controls. The maximum increase of compressive strength was 33% when replaced fly ash with 20% of glass powder at 8 molar NaOH concentration of sodium hydroxide solution. The microstructure evaluations show the remaining particles of raw materials and the compatible of hydration reaction and polymerization when having limestone powder in the mix proportion. Furthermore, the powder acts as a filler in the gels.

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The effect of 60Co gamma irradiation on coal fly-ash geopolymer paste setting time

Nuclear Technology and Radiation Protection ◽

10.2298/ntrp2002150r ◽

2020 ◽

Vol 35 (2) ◽

pp. 150-153

Author(s):

Luka Rubinjoni ◽

Srboljub Stankovic ◽

Boris Loncar

Keyword(s):

Fly Ash ◽

Radioactive Waste ◽

Waste Treatment ◽

Low Cost ◽

Coal Fly Ash ◽

Setting Time ◽

Initial Setting Time ◽

Final Setting Time ◽

Intermediate Level Radioactive Waste ◽

Geopolymer Paste

Cementation is the baseline technology for conditioning of low to intermediate level radioactive waste. Geopolymers, a class of alkali activated binders, are a promising new material for radioactive waste treatment. Coal fly-ash based geopolymers are a low-cost, low greenhouse gas footprint alternative to metakaolin based materials. Both the grouting of sludge/powders/liquids and encapsulation of solids/compacted waste rely on the grout maintaining optimal flow (rheological properties) during the mixing and pouring operations, and achieving a set leading to proper long term solidification (mechanical properties). The initial and final setting time for fly-ash geopolymer paste, based on the SRPS EN 196-3 standard, has been measured upon irradiation by gamma rays in a 60Co reference field positioned with a kerma air rate of 3.42 mGys?1. The binder paste was prepared using fly-ash from the TENT B power plant's electrostatic filters without further sieving, activated by water glass with module 1.5 and mixed with distilled water until a satisfactory flow was obtained, and poured into the sample and control molds. The initial and final setting times for the irradiated sample and non-irradiated control were determined by the Vicat apparatus. The irradiated sample demonstrated an 11 % shorter initial setting time, and 16 % shorter final setting time, compared to the control.

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