Carbon dioxide equivalent (CO2-e) emissions: A comparison between geopolymer and OPC cement concrete

https://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/139940/1/j.jclepro.2011.02.010.pdf

Costs and carbon emissions for geopolymer pastes in comparison to ordinary portland cement

Geopolymer concrete: A review of some recent developments

An environmental evaluation of geopolymer based concrete production: reviewing current research trends

Effect of GGBFS on setting, workability and early strength properties of fly ash geopolymer concrete cured in ambient condition

This Research Report describes the first part of the work carried out by the geopolymer research group at Curtin University of Technology. It describes the development and properties of heat-cured low-calcium fly ash-based geopolymer concrete. This Report will be followed by two other Reports describing the long-term properties of geopolymer concrete, and the behaviour of reinforced geopolymer concrete beams and columns.

/pdf/development-and-properties-of-low-calcium-fly-ash-based-dgjq8opf8k.pdf

Development and properties of low-calcium fly ash-based geopolymer concrete

In recent years, attempts to increase the utilisation of fly ash to partially replace the use of Portland cement in concrete are gathering momentum. Geopolymer concrete is a ‘new’ material that does not need the presence of Portland cement as a binder. Instead, activating the source materials such as fly ash that are rich in Silicon (Si) and Aluminium (Al) using high alkaline liquids produces the binder required to manufacture the concrete. Hence, concrete with no cement.This paper presents information on fly ash-based geopolymer concrete. The paper covers the material and the mixture proportions, the manufacturing process, and the influence of various parameters on the properties of fresh and hardened concrete.

/pdf/fly-ash-based-geopolymer-concrete-5dsk3wt5i5.pdf

Fly Ash-Based Geopolymer Concrete

The objectives of this paper are to present the results of experimental study and analysis on the behaviour and the strength of reinforced geopolymer concrete slender columns. The experimental work involved testing of twelve columns under axial load and uniaxial bending in single curvature mode. The compressive strength of concrete for the first group of six columns was about 40 MPa, whereas concrete with a compressive strength of about 60 MPa was used in the other six columns. The other variables of the test program were longitudinal reinforcement ratio and load eccentricity. The test results gathered included the load carrying capacity, the load-deflection characteristics, and the failure modes of the columns. The analytical work involved the calculation of ultimate strength of test columns using the methods currently available in the literature. A simplified stability analysis is used to calculate the strength of columns. In addition, the design provisions contained in the Australian Standard AS3600 and the American Concrete Institute Building Code ACI318-02 are used to calculate the strength of geopolymer concrete columns. This paper demonstrates that the design provisions contained in the current standards and codes can be used to design reinforced fly ash-based geopolymer concrete columns.

/pdf/fly-ash-based-geopolymer-concrete-study-of-slender-4klqesmajy.pdf

Fly ash-based geopolymer concrete: study of slender reinforced columns

This paper describes the effects of several factors on the properties of fly ash based geopolymer concrete, especially the compressive strength. The test variables included were the age of concrete, curing time, curing temperature, quantity of superplasticizer, the rest period prior to curing, and the water content of the mix.
 
The test results show that the compressive strength of geopolymer concrete does not vary with age, and curing the concrete specimens at higher temperature and longer curing period will result in higher compressive strength. Furthermore, the commercially available Naphthalene-based superplasticizer improves the workability of fresh geopolymer concrete. The start of curing of geopolymer concrete at elevated temperatures can be delayed at least up to 60 minutes without significant effect on the compressive strength. The test data also show that the water content in the concrete mix plays an important role.

/pdf/factors-influencing-the-compressive-strength-of-fly-ash-k67404z1j9.pdf

Factors influencing the compressive strength of fly ash-based geopolymer concrete

When fly ash-based geopolymer mortars were exposed to a temperature of 800 °C, it was found that the strength after the exposure sometimes decreased, but at other times increased. This paper shows that ductility of the mortars has a major correlation to this strength gain/loss behaviour. Specimens prepared with two different fly ashes, with strengths ranging from 5 to 60 MPa, were investigated. Results indicate that the strength losses decrease with increasing ductility, with even strength gains at high levels of ductility. This correlation is attributed to the fact that mortars with high ductility have high capacity to accommodate thermal incompatibilities. It is believed that the two opposing processes occur in mortars: (1) further geopolymerisation and/or sintering at elevated temperatures leading to strength gain; (2) the damage to the mortar because of thermal incompatibility arising from non-uniform temperature distribution. The strength gain or loss occurs depending on the dominant process.

/pdf/an-investigation-of-the-mechanisms-for-strength-gain-or-loss-1as17gkqg8.pdf

B. V. Rangan

Papers

Development and properties of low-calcium fly ash-based geopolymer concrete

Fly Ash-Based Geopolymer Concrete

Fly ash-based geopolymer concrete: study of slender reinforced columns

Factors influencing the compressive strength of fly ash-based geopolymer concrete

An investigation of the mechanisms for strength gain or loss of geopolymer mortar after exposure to elevated temperature