Influence of Calcined Flue Gas Desulfurization Gypsum and Calcium Aluminate on the Strength and AFt Evolution of Fly Ash Blended Concrete under Steam Curing

In order to improve the early strength of fly ash blended cement concrete under steam curing conditions, fly ash was partly substituted by calcined flue gas desulfurization (FGD) gypsum and active calcium aluminate. The effect of the composition and curing condition on the workability, mechanical property, and volume stability was systematically evaluated. The variety of hydration products and the evolution was determined by XRD to explore the formation kinetic of ettringite. Results show that the addition of calcined FGD gypsum and active calcium aluminate is able to improve the early compressive strength but using more FGD gypsum and a high sulfur aluminum ratio leads to a reduction in compressive strength from 28 to 90 days due to the increment of ettringite and crystallization of dihydrate gypsum. Both the free expansion ratio and limited expansion exhibited a continuous increasement with time, especially in the first 14 days of testing. Cracks were not observed on the surface of samples immersed in water for a year. The improvement of strength and shrinkage resistance is mainly due to the formation of ettringite generated before 14 days and the precipitation was highly limited from 14 to 28 days. Moreover, the characteristic peak of gypsum appeared after 28 days, indicating the conversion of partial of calcined FGD gypsum. The work presented here provides a new solution for improving the early strength of fly ash concrete without reducing the later strength and consuming extra energy.

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Effect of Gypsum on Strength Development of Steam-Cured Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.1085 ◽

2011 ◽

Vol 194-196 ◽

pp. 1085-1088

Author(s):

Zhi Min He ◽

Xiao Ju Shen ◽

Jun Zhe Liu

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Strength Development ◽

Early Age ◽

Strength Gain ◽

Fly Ashes ◽

Steam Curing ◽

Gain Rate ◽

Early Strength ◽

Chemical Activator

The use of fly ashes for cement-replacement purposes, especially in high volumes, decreases rate of early strength development of the steam curing concrete. To resolve it, this paper developed a new steam-cured concrete incorporating fly ash and a chemical activator (gypsum). Experiments were conducted to investigate the mechanical properties at early and later ages of steam and standard curing concretes. The corresponding mechanism was also discussed by testing the microstructure of concretes. Results indicate that the demoulding compressive strength of steam curing concrete with 4% gypsum dosage can meet production requirements, and compressive strength of this concrete at later ages increase well. Compared with that of ordinary pure cement steam-cured concrete, concrete with 4% gypsum has a higher compressive strength gain rate. At an early age, addition of the gypsum can distinctly accelerate the extent of hydration of the steam curing fly ash cement systems, and thus the microstructure of concrete becomes denser. However, in standard curing condtion, the effect of gypsum is not distinct.

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Effect of Using Flue-Gas Desulfurization Gypsum and Water Treatment Sludge on Compressive Strength of Cement Mortar

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.897.143 ◽

2021 ◽

Vol 897 ◽

pp. 143-149

Author(s):

Weerawan Chalermsakulkit ◽

Nuta Supakata

Keyword(s):

Compressive Strength ◽

Water Treatment ◽

Flue Gas ◽

Building Materials ◽

Cement Mortar ◽

Fine Sand ◽

Flue Gas Desulfurization ◽

Fine Aggregate ◽

Water Treatment Sludge ◽

Fgd Gypsum

Ordinary Portland cement (OPC) is a material that is widely used in construction. The production of OPC creates large amounts of carbon dioxide. Mortar is one of the building materials that uses cement as the main ingredient, including the use of natural sand as a fine aggregate. Therefore, to reduce the use of cement and natural materials, flue-gas desulfurization (FGD) gypsum was used instead of OPC, and water treatment sludge (WTS) was used instead of fine sand to create cement mortar. This research used both materials as ingredients in the production of cement mortar and helped to reduce waste in the environment. The objective is to study the suitable ratios of FGD gypsum and WTS in the production of cement mortar. As for the binder, FGD gypsum was used instead of OPC at 0%, 10%, 20%, 30%, and 40%. Instead of fine sand, WTS was used at 0%, 5%, 10%, and 15%. The cement mortar was tested after 7 days for compressive strength. It was found that the cement mortar made with increased ratios of FGD gypsum and WTS decreased in compressive strength.

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Utilization of thermally treated flue gas desulfurization (FGD) gypsum and class-C Fly Ash (CFA) to prepare CFA-based geopolymer

Journal of Wuhan University of Technology-Mater Sci Ed ◽

10.1007/s11595-013-0654-0 ◽

2013 ◽

Vol 28 (1) ◽

pp. 132-138 ◽

Cited By ~ 8

Author(s):

Xiaolu Guo ◽

Huisheng Shi ◽

Warren A. Dick

Keyword(s):

Fly Ash ◽

Flue Gas ◽

Flue Gas Desulfurization ◽

Fgd Gypsum ◽

Class C ◽

Thermally Treated

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Use of Flue Gas Desulfurization Gypsum, Construction and Demolition Waste, and Oil Palm Waste Trunks to Produce Concrete Bricks

Crystals ◽

10.3390/cryst10080709 ◽

2020 ◽

Vol 10 (8) ◽

pp. 709 ◽

Cited By ~ 1

Author(s):

Lalitsuda Phutthimethakul ◽

Park Kumpueng ◽

Nuta Supakata

Keyword(s):

Compressive Strength ◽

Water Absorption ◽

Flue Gas ◽

Oil Palm ◽

Power Plants ◽

Construction And Demolition Waste ◽

Flue Gas Desulfurization ◽

Demolition Waste ◽

Fgd Gypsum ◽

Concrete Production

This research aims to study the utilization of waste from power plants, construction and demolition, and agriculture by varying the ratios of flue-gas desulfurization (FGD) gypsum, construction and demolition waste (CDW), and oil palm trunks (OPT) in concrete production. This research used these as the raw materials for the production of concrete bricks of 15 × 15 × 15 cm. There were 12 ratios of concrete brick, fixing 5.5 wt% of FGD gypsum to replace Portland cement and substituting coarse sand with 0 wt%, 25 wt%, 50 wt%, or 75 wt% of CDW, and gravel with 0 wt%, 0.5 wt%, and 1 wt% of OPT. The initial binder:fine aggregate:coarse aggregate ratio was 1:2:4 and the water to cement ratio was 0.5, curing in water at room temperature for 28 days. Then, all concrete brick specimens were tested for compressive strength and water absorption. From the experiment, it was found that the highest compressive strength of concrete brick specimens was 45.18 MPa, which was produced from 5.5% gypsum without CDW and OPT, while 26.84 MPa was the lowest compressive strength obtained from concrete bricks produced from 5.5% FGD gypsum, 75% CDW, and 1% OPT. In terms of usage, all proportions can be applied in construction and building work because the compressive strength and water absorption were compliant with the Thai Industrial Standard TIS 57-2530 and TIS 60-2516.

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96/05998 Roller compacted base course construction using lime stabilized fly ash and flue gas desulfurization sludge byproduct

Fuel and Energy Abstracts ◽

10.1016/s0140-6701(97)83407-8 ◽

1996 ◽

Vol 37 (6) ◽

pp. 425 ◽

Cited By ~ 1

Keyword(s):

Fly Ash ◽

Flue Gas ◽

Flue Gas Desulfurization ◽

Base Course

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Contaminant Mobility in Soil Columns Amended with Fly Ash and Flue Gas Desulfurization Gypsum

Biogeochemistry of Trace Elements in Coal and Coal Combustion Byproducts ◽

10.1007/978-1-4615-4155-4_15 ◽

1999 ◽

pp. 247-258 ◽

Cited By ~ 2

Author(s):

C. F. Ishak ◽

J. C. Seaman ◽

M. E. Sumner ◽

W. P. Miller

Keyword(s):

Fly Ash ◽

Flue Gas ◽

Flue Gas Desulfurization ◽

Soil Columns ◽

Contaminant Mobility

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THE INFLUENCE OF THE USE OF RECYCLED GYPSUM ON THE PROPERTIES OF GYPSUM PRODUCTS IN LABOR CONDITIONS

Acta Polytechnica CTU Proceedings ◽

10.14311/app.2020.26.0081 ◽

2020 ◽

Vol 26 ◽

pp. 81-85

Author(s):

Hana Sekavová ◽

Jakub Herrmann ◽

Zdeněk Prošek ◽

Miroslav Nyč ◽

George Karra’a

Keyword(s):

Flue Gas ◽

Flue Gas Desulfurization ◽

Volume Changes ◽

Fgd Gypsum ◽

Labor Conditions ◽

Setting Times ◽

Elasticity Module ◽

First Results ◽

Recycled Gypsum ◽

Recycled Material

The article presents the first results from research, which is deal with recycling of plaster boards and use of the resulting material. The research is carried out within the project MPO Trio c. FV30359 “Recyklace sádrokartonových desek a nová materiálová využití s pridanou hodnotou – GIPSRec”. The plasterboards are produced of stucco, which is calcinated of Flue Gas Desulfurization Gypsum (FGD Gypsum). There is possibility to replace a part of this stucco with recycled material. There is opportunity for saving costs for production. The question how this utilization can change the properties of the products is very important and it is necessary to find the possible improvement or deterioration. This is the objective of this research. The effect on properties was monitored on the samples which was prepared of only pure stucco and of stucco with part of recycled material. There was observed water ratio (splash test), setting times, volume changes, flexural strength, compressive strength and elasticity module.

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