Effect of Precursor Blending Ratio and Rotation Speed of Mechanically Activated Fly Ash on Properties of Geopolymer Foam Concrete

Abstract

This research used fly ash and slag to create geopolymer foam concrete. They were activated with an alkali, resulting in a chemical reaction that produced a gel that strengthened the concrete’s structural integrity. The experimental approach involved varying the fly ash content in the precursors at incremental percentages (10%, 30%, 50%, 70% and 90%) and subjecting the fly ash to mechanical activation through a planetary ball mill at distinct rotational speeds (380, 400, 420 and 440 rpm). The investigation discerned that the fly ash content and particle structure exert a discernible influence on macroscopic properties, including flowability, air generation height, compressive strength, dry density and microstructural characteristics such as pore distribution and hydration product arrangement in the geopolymer foam concrete. Employing analytical techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM), it was deduced that diminishing the fly ash content correlates with an enhancement in compressive strength. Furthermore, the specific strength of the geopolymer foam concrete reached a peak of 0.041 when the activated fly ash in the planetary ball mill rotated at 420 rpm, manifesting a lightweight and high-strength outcome.

Production of Glass Foam in a Microwave Oven Using Agro-Industrial Waste as Raw Material

“…The bottles were washed and oven-dried before being manually crushed to yield particles <10 mm. These particles were further processed in a ball mill [11] (TS RUBENS, São Paulo, Brazil) at a speed of 100 rpm with steel grinding bodies (36.5; 30.2; 25.4; 19.1; 15.9 mm) until they were fine enough to pass through a 150 ABNT standard mesh sieve (106 μm). The milling time was not regulated.…”

“…This burden primarily arises from its high energy consumption, significant emissions that contribute to the greenhouse effect, and the generation of vast amounts of solid waste [9,10]. The global trend towards building taller structures has escalated concrete production, making it the most utilized material worldwide [11][12][13][14], with annual production nearing 10 billion cubic meters [15]. Research has indicated that construction processes can integrate various waste materials into concrete, such as vitreous foams [7,8], bamboo fibers [16], PET bottles [17], and glass bottles [18], to mitigate environmental impacts.…”