Strength Characteristics and Rheological Behavior of a High Level of Fly Ash in the Production of Concrete

Hanane Boutkhil; Somia Fellak; Badr Aouan; Saliha Alehyen; Riaz Ullah; Ahmed Bari; Hafize Fidan; Sezai Ercisli; Amine Assouguem; M'hamed Taibi

doi:10.1021/acsomega.4c00147

Strength Characteristics and Rheological Behavior of a High Level of Fly Ash in the Production of Concrete

ACS Omega. 2024 Mar 18;9(12):14419-14428. doi: 10.1021/acsomega.4c00147. eCollection 2024 Mar 26.

Authors

Hanane Boutkhil¹, Somia Fellak², Badr Aouan¹, Saliha Alehyen¹, Riaz Ullah³, Ahmed Bari⁴, Hafize Fidan⁵, Sezai Ercisli⁶, Amine Assouguem^{7

8}, M'hamed Taibi¹

Affiliations

¹ Physico-Chemical Laboratory of Inorganic and Organic Materials (LPCMIO), Higher Normal School (E.N.S) Avenue Mohamed Bel Hassan El Ouazzani, BP 5118, Mohammed V University (UM5). Rabat 10000, Morocco.
² Department of Chemistry, Faculty of Sciences and Technology, Sidi Mohamed Ben Abdellah University, B.P. 2202-Imouzzer Road, Fez, Morocco.
³ Department of Pharmacognosy College of Pharmacy, King Saud University, Riyadh 11421, Saudi Arabia.
⁴ Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11421, Saudi Arabia.
⁵ Faculty of Economics, Department of Tourism and Culinary Management, University of Food Technologies, Plovdiv 4002, Bulgaria.
⁶ Department of Horticulture, Faculty of Agriculture, Ataturk University, Erzurum 25240, Turkey.
⁷ Laboratory of Functional Ecology and Environment, Faculty of Sciences and Technology, Sidi Mohamed Ben Abdellah University, P.O. Box 2202, Imouzzer Street, Fez 30000, Morocco.
⁸ Laboratory of Applied Organic Chemistry, Faculty of Sciences and Technology, Sidi Mohamed Ben Abdellah University, P.O. Box 2202 Imouzzer Street, Fez 30000, Morocco.

Abstract

This study investigates the valorization of coal fly ash (FA-C) generated by the Jerada thermal power plant, aiming to address the pressing need for sustainable construction practices and reduced greenhouse gas emissions in the concrete industry. It is widely used as a pozzolanic material. The key objective is to harness the potential of FA-C as a supplementary material in concrete production, which not only reduces costs but also contributes to environmental sustainability. To achieve this objective, various concrete mixtures were formulated, with FA-C serving as a partial substitute for cement at percentages ranging from 15 to 50%. According to ASTM standards, compressive strength tests were conducted on standard-sized cylinders at 7 and 28 days. The results revealed that the blend containing 15% FA-C exhibited the highest compressive strength, indicating its effectiveness as a concrete additive. Furthermore, this study delves into the rheological properties of concrete mixes, an essential aspect of successful concrete processing. It was observed that a higher replacement level of FA-C significantly improved the rheology, leading to reduced water demand and a linear decrease in plastic viscosity over time. The rheological parameters stabilized after a certain period, demonstrating the controllability of concrete flow behavior with FA-C. The investigation also employed three analytical methods-Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM)-to comprehensively analyze both raw materials and processed samples. FTIR analysis highlighted the minimal impact of FA particles on hydration product formation, emphasizing the role of FA-C in enhancing the concrete's strength. XRD analysis confirmed the presence of an amorphous phase crucial for FA's reactivity. SEM observations revealed that concrete with 15% FA-C exhibited a more uniform microstructure with aluminosilicate gel, while 50% FA-C mixes showed increased porosity and nonhomogeneity due to unreacted FA particles.