Alkali-Activated Cement (AAC) From Fly Ash and High-Magnesium Nickel Slag

This paper presents a study of parameters affecting the fibre pull out capacity and strain-hardening behaviour of fibre-reinforced alkali-activated cement composite (AAC). Fly ash is a common aluminosilicate source in AAC and was used in this study to create fly ash based AAC. Based on a numerical study using Taguchi’s design of experiment (DOE) approach, the effect of parameters on the fibre pull out capacity was identified. The fibre pull out force between the AAC matrix and the fibre depends greatly on the fibre diameter and embedded length. The fibre pull out test was conducted on alkali-activated cement with a capacity in a range of 0.8 to 1.0 MPa. The strain-hardening behaviour of alkali-activated cement was determined based on its compressive and flexural strengths. While achieving the strain-hardening behaviour of the AAC composite, the compressive strength decreases, and fine materials in the composite contribute to decreasing in the flexural strength and strain capacity. The composite critical energy release rate in AAC matrix was determined to be approximately 0.01 kJ/m 2 based on a nanoindentation approach. The results of the flexural performance indicate that the critical energy release rate of alkali-activated cement matrix should be less than 0.01 kJ/m 2 to achieve the strain-hardening behaviour.

Download Full-text

MECHANICAL PROPERTIES OF FLY ASH-BASED ALKALI-ACTIVATED CEMENT USING A STATISTICAL ANALYSIS TECHNIQUE

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2014.38 ◽

2014 ◽

Vol 1 (1) ◽

Author(s):

Hyuk Lee ◽

Vanissorn Vimonsatit

Keyword(s):

Mechanical Properties ◽

Compressive Strength ◽

Statistical Analysis ◽

Fly Ash ◽

Silica Fume ◽

Dry Density ◽

Analysis Method ◽

Solid Ratio ◽

Alkali Activated ◽

Alkali Activated Cement

This paper presents the mechanical properties of fly ash-based alkali-activated cement (AAC). A statistical analysis method was used to determine the effect of mix proportion parameters on the dry density and compressive strength of fly ash-based AAC pastes and mortars. For that purpose, sample mixtures were designed according to Taguchi’s experimental design method, i.e., in a L9 orthogonal array. Four factors were selected: “silica fume content” (SF), “sand to solid ratio” (s/c), “liquid to solid ratio” (l/s), and “superplasticiser content” (SP). The experimental results were analysed by using signal to noise for quality control of each mixture, and analysis of variance (ANOVA) was used to determine the significant effect on the compressive strength of fly ash-based AAC. Furthermore, a regression-analysis method was used to predict the compressive strength according to the variation of the four factors. Results indicated that silica fume is the most influencing parameter on compressive strength, which could be decreased by superplasticiser and l/s ratio. There is no significant effect of sand-to-cementitious ratio on compressive strength of fly ash-based AAC. The dry density decreases as the sand-to-cementitious ratio is decreased. The increasing l/s ratio and superplasticiser dosage could further decrease the dry density of fly ash-based AAC.

Download Full-text

Research on Mechanism of Architectural Wastes Solidified by Alkali-Activated Cement and Fly Ash

Advanced Materials Research ◽

10.4028/scientific5/amr.446-449.2708 ◽

2012 ◽

Vol 446-449 ◽

pp. 2708-2713

Author(s):

Qin Li ◽

Xiao Jun Zhou ◽

Zhuo Yin Jiang ◽

Ke Wei Sun

Keyword(s):

Fly Ash ◽

Alkali Activated ◽

Alkali Activated Cement

Download Full-text

Class C fly ash-based alkali activated cement as a potential alternative cement for CO2 storage applications

Journal of Petroleum Science and Engineering ◽

10.1016/j.petrol.2021.108408 ◽

2021 ◽

pp. 108408

Author(s):

Priyesh Jani ◽

Abdulmohsin Imqam

Keyword(s):

Fly Ash ◽

Co2 Storage ◽

Potential Alternative ◽

Class C ◽

Alkali Activated ◽

Alkali Activated Cement

Download Full-text

Adiabatically cured, alkali-activated cement-based wasteforms containing high levels of fly ash

Cement and Concrete Research ◽

10.1016/s0008-8846(01)00589-0 ◽

2001 ◽

Vol 31 (10) ◽

pp. 1437-1447 ◽

Cited By ~ 24

Author(s):

A.R Brough ◽

A Katz ◽

G.-K Sun ◽

L.J Struble ◽

R.J Kirkpatrick ◽

...

Keyword(s):

Fly Ash ◽

Alkali Activated ◽

Alkali Activated Cement

Download Full-text

Investigation of the Effect of Mixing Time on the Mechanical Properties of Alkali-Activated Cement Mixed with Fly Ash and Slag

Materials ◽

10.3390/ma14092301 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2301

Author(s):

Taewan Kim ◽

Choonghyun Kang

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Mixing Time ◽

Blending Method ◽

Mixing Method ◽

The Difference ◽

High Alkali ◽

Mixed Water ◽

Alkali Activated ◽

Alkali Activated Cement

This is an experiment on the effect of mixing time for alkali-activated cement (AAC) using a binder mixed with ground granulated blast furnace slag (slag) and fly ash (FA) in a ratio of 1:1 on the mechanical properties. The mixing method of ASTM C305 was used as the basic mixing method, and the following mixing method was changed. Simply adding the same mixing time and procedure, the difference in the order of mixing slag and FA, and controlling the amount of activator and mixed water were considered. As a result of the experiment, the addition of the same mixing time and procedure, pre-injection of slag, and high-alkali mixed water in which half of the activator and mixing water were mixed showed the highest mechanical properties and a dense pore structure. As a result, the design of a blending method that can promote the activation action of slag rather than FA at room temperature was effective in improving the mechanical properties of AAC. In addition, these blending factors showed a clearer effect as the concentration of the activator increased. Through the results of this experiment, it was shown that high-temperature curing, high fineness of the binder, or even changing the setting of the mixing method without the use of excessive activators can lead to an improvement of mechanical properties.

Download Full-text

Characteristics of Preplaced Aggregate Concrete Fabricated with Alkali-Activated Slag/Fly Ash Cements

Materials ◽

10.3390/ma14030591 ◽

2021 ◽

Vol 14 (3) ◽

pp. 591

Author(s):

Salman Siddique ◽

Hyeju Kim ◽

Hyemin Son ◽

Jeong Gook Jang

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Water Absorption ◽

Ultrasonic Pulse Velocity ◽

Ultrasonic Pulse ◽

Pulse Velocity ◽

Cement Grout ◽

Aggregate Concrete ◽

Alkali Activated ◽

Alkali Activated Cement

This study assesses the characteristics of preplaced aggregate concrete prepared with alkali-activated cement grout as an adhesive binder. Various binary blends of slag and fly ash without fine aggregate as a filler material were considered along with different solution-to-solid ratios. The properties of fresh and hardened grout along with the properties of hardened preplaced concrete were investigated, as were the compressive strength, ultrasonic pulse velocity, density, water absorption and total voids of the preplaced concrete. The results indicated that alkali-activated cement grout has better flowability characteristics and compressive strength than conventional cement grout. As a result, the mechanical performance of the preplaced aggregate concrete was significantly improved. The results pertaining to the water absorption and porosity revealed that the alkali-activated preplaced aggregate concrete is more resistant to water permeation. The filling capacity based on the ultrasonic pulse velocity value is discussed to comment on the wrapping ability of alkali-activated cement grout.

Download Full-text