Reaction kinetics of red mud-fly ash based geopolymers: Effects of curing temperature on chemical bonding, porosity, and mechanical strength

Novel hemp fiber reinforced geopolymer composites were fabricated. The matrix was a new geopolymer based on a mixture of red mud and fly ash. Chopped, randomly oriented hemp fibers were used as reinforcement. The mechanical properties of the geopolymer composite, such as diametral tensile (DTS) (or Brazilian tensile) strength and compressive strength (CS), were measured. The geopolymer composites reinforced with 9 vol.% and 3 vol.% hemp fiber yielded average DTS values of 5.5 MPa and average CS values of 40 MPa. Scanning electron microscopy (SEM) studies were carried out to evaluate the microstructure and fracture surfaces of the composites. The results indicated that the addition of hemp fiber is a promising approach to improve the mechanical strength as well as to modify the failure mechanism of the geopolymer, which changed from brittle to “pseudo-ductile”.

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A Review on Heat Released in early Geopolymerization by Calorimetric Study

Materials Science Forum ◽

10.4028/www.scientific.net/msf.967.236 ◽

2019 ◽

Vol 967 ◽

pp. 236-240

Author(s):

Mohamed Rosnita ◽

A.R. Razak ◽

Mohd Mustafa Al Bakri Abdullah

Keyword(s):

Reaction Kinetics ◽

Chemical Reaction ◽

Alkaline Solution ◽

Curing Temperature ◽

Calorimetric Study ◽

Calorimetric Data ◽

Pozzolanic Material ◽

Exothermic Chemical Reaction ◽

Kinetics Of ◽

Heat Released

An exothermic chemical reaction between cement and water or is called as hydration of cement produced heat in which gives significance impact to the cement or concrete produced. This hydration of cement is similar to geopolymerization as in geopolymerization, heat is liberated when any pozzolanic material mixes with alkaline solution. Heat released for both hydration of cement and geopolymerization can be measured in a form of calorimetric data. This paper reviews on the use of heat released information for a better understanding on the reaction kinetics of geopolymerization and correlating the heat released with several factors including concentration of alkaline solution, mixing designation and curing temperature.

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Reaction kinetics of fly ash geopolymerization: Role of particle size controlled by using ball mill

Advanced Powder Technology ◽

10.1016/j.apt.2019.03.003 ◽

2019 ◽

Vol 30 (5) ◽

pp. 1079-1088 ◽

Cited By ~ 9

Author(s):

S.K. Nath ◽

Sanjay Kumar

Keyword(s):

Particle Size ◽

Fly Ash ◽

Reaction Kinetics ◽

Ball Mill ◽

Kinetics Of ◽

Size Controlled

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Water-Resistant Modification of Desulphurization Gypsum Block

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.182-183.278 ◽

2012 ◽

Vol 182-183 ◽

pp. 278-282

Author(s):

Yan Mu ◽

Ying Li Fu ◽

Feng Qing Zhao

Keyword(s):

Fly Ash ◽

Mechanical Strength ◽

High Performance ◽

Water Resistance ◽

Curing Temperature ◽

Curing Time ◽

Operating Property ◽

High Mechanical Strength ◽

Calcined Gypsum ◽

Hemi Hydrate

A high performance water resistance agent KD-3 prepared from OPC cement, fly ash, slag and additives was used for the modification of hemi-hydrate desulphurization gypsum. Various factors on gypsum block were investigated. The prepared gypsum block possesses excellent water-resistance, good operating property and high mechanical strength. The optimized results was obtained: calcined gypsum 74.9%, KD-3 25%, retarder 0.1%, curing temperature 60°C and curing time 16h.

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Thermal Reaction Kinetics of Fly Ash Cement Paste at the Age of 28 Days

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.668-669.91 ◽

2014 ◽

Vol 668-669 ◽

pp. 91-94 ◽

Cited By ~ 1

Author(s):

Xiao Fang He ◽

Chang Wen Miao ◽

Yong Hao Wu ◽

Xin Xin Cao ◽

Dan Liu

Keyword(s):

Activation Energy ◽

Fly Ash ◽

Apparent Activation Energy ◽

Reaction Kinetics ◽

Thermal Reaction ◽

Physical Parameters ◽

Scanning Calorimetry ◽

Kinetics Parameters ◽

Cement Pastes ◽

Kinetics Of

The thermal reaction kinetics of fly ash cement pastes were studied by Differential Scanning Calorimetry (DSC) and Thermal Gravity Analysis-Differential Thermal Gravity (TG-DTG) method, the kinetics parameters such as apparent activation energy was calculated by the Kissinger method, and the physical parameters were obtained. The result show that the fly ash cement pastes performance three endothermic reaction stages at different heating rates, peak temperatures of each stage at the range of 91.85~121.08°C, 453.93~496.48°C, and 680.21~751.62°C. TG-DTG show there were three thermal decomposition stages, thermal dehydration reaction apparent activation energy of fly ash cement pastes in each stage were 47.23kJ/mol, 128.84kJ/mol, and 134.07kJ/mol.

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