Fly Ash Micro-Aggregate Effect

The positive results could have occurred from the improvement of matrix structure through the micro-aggregate effect that promoted a more compacted microstructure [67]. Increasing the content of CF beyond 1% is effective in increasing the compressive strength of geopolymer mortar. ... Recycled aggregate high calcium fly ash geopolymer concrete ...

The micro-aggregate effect occurs when the fly ash is added to the cement-stabilized macadam material. The aggregate without the fly ash is not compact. The spherical particles of the fly ash can fill the micropores formed by the sand, and the aggregate compactness is significantly improved [31,32,33]. The cement hydration products are filled ...

"Fly ash effect" refers to a series of effects including morphological effect, micro-aggregate effect and active effect. With the enlargement of FLA particle size, the morphological effect and micro-aggregate effect weaken …

The coating effect of fly ash on light aggregate could reduce water consumption and raise the strength, workability, and durability of concrete to a certain degree. ... ing, and cooling after grinding and mixing. The inside of fly ash glass is filled with micro-, uniform, and connected or closed pores with volume as high as 80–95% ...

Rheological behavior of high volume fly ash mixtures containing micro silica for digital construction application. Mater. Lett., 237 ... Physical filling effect of aggregate micro fines in cement concrete. Constr. Build. Mater., 41 (2013), pp. 812-814, 10.1016/j.conbuildmat.2012.12.037.

Fly ash can also serve as micro aggregate in concrete, and this function is enhanced as the fly ash content increases, but diminishes with age (Wang et al., 2004a). Lam et al. (2000) introduced a model of FC (fly ash + cement) system to simulate the relationship among the water-to-cement (w/c) ratio, the cement hydration degree, and the gel ...

This research systematically investigated the effects of fly ash (FA) in magnesium ammonium phosphate cement (MAPC) on the fluidity, setting time, compressive strength, and water resistance. ... FA has a micro-aggregate effect in the hardened MAPC. After adding FA, the early strength (1 h, 1 d) decreased, while the later-stage

In addition, the morphological effect [5], the activity effect [6] and the micro-aggregate effect [7] of fly ash will make the cement paste denser as well as firmer and improve the interface microstructure between it and the coarse aggregate, which can not only reduce the hydration heat and creep of the concrete in the early stage, but also ...

This paper explores the physical, mechanical and durability characteristics of Fly ash—ground granulated blast furnace slag (GGBS) based Geopolymer aggregates include Specific gravity, impact value, crushing value, loss angles abrasion value, attrition value and water absorption respectively. Besides, scanning electron microscopy (SEM) was done to diagnose …

Multiscale modeling was used to simulate fly ash recycled aggregate concrete's micro-, meso-, and macroscale behavior. ... Synergic effect of recycled aggregate, fly ash, and hydrated lime in concrete production. J Build Eng, vol. 70 (2023), 10.1016/j.jobe.2023.106370. Google Scholar [9]

A further increase in fly ash content will result in a decrease in the cohesion and internal friction angle. When the fly ash content is 10%, the cohesion and internal friction angle reach the maximum. At a short curing age, fly ash acts mainly as a micro-aggregate and directly fills the pores on the surface of calcareous sand.

The aim of this paper is to study the particle size effect of fly ash (FLA) on pore structure and strength of Fly Ash ed Geopolymer (FAFG). Information on the macro-pores such as macro-pore size and distribution of …

The performance of fly ash blended concrete is influenced by the pozzolanic and/or micro-aggregate effect of fly ash particles based on the replacement levels. Dominance of either of this effect greatly influences the mechanical and fracture properties of fly ash blended concrete. In view of this, in the present study, 0%, 20%, 30%, 35%, 40%, 50%, 60% and 70% …

Micro-cracks and unreacted "glass microsphere" fly ash particles are clearly seen in S0-1.5-6 and S25-1.5-6 samples, and the microstructure is loose. The unhydrated fly ash particles have a filling effect on the matrix, and the matrix is relatively continuous.

In addition, for the low-volume fly ash concrete samples, the higher w/b can lead to a larger amount of unreacted fly ash particles, which shows a more significant "micro-aggregate effect". Hence, the chloride diffusion resistance of concrete incorporating fly …

Fly ash - Class F fly ash conforming to ASTM C618 [48] was used as cement replacement material. Fly ash was obtained from the thermal power plant located in the province of Zonguldak in the Black Sea region. The chemical properties of fly ash are presented in Table 1.In addition, the particle size distributions of cement and fly ash were determined by Mastersizer.

In this work, the coarse aggregate was replaced partially by Fly ash aggregates in different proportions. Total eleven concrete mixes are cast and tested for strength properties, …

This research paper presents a detailed investigation into the use of waste fly ash–based lightweight aggregate developed by a sintering process in concrete. These sintered fly ash (SF) aggregates are replaced with natural …

Many researchers devoted themselves to the application and the action mechanism of fly ash in cementing material system in the past 70 years, and the hypothesis of "fly ash effects" was put forward, including three effects of fly ash in concrete, i.e., morphological, active and micro-aggregate effects [8], [9], [10], [11].It is indicated that in the early stages, fly …

The recent development of sustainable green cement technology has brought hope on fly ash for production alkali-activated cementitious materials (AACs), due to the high content of SiO 2 and Al 2 O 3 (the sum of SiO 2, Al 2 O 3, and Fe 2 O 3 is approximately 70 %). The practicability of using fly ash to produce AACs has been proven [[24], [25], [26]].Fly ash has …

Firstly, fly ash promotes pozzolanic activity in cement, secondly, it contributes for micro aggregate effect and thirdly morphological effect. Among all the functions stated pozzolanic action is considered as the main effect which states that the Al 2 O 3 and SiO 2 in FA is activated by Portlandite (CH) formed during the cement hydration and ...

It was reported that fly ash in concrete mainly possesses three effects, namely morphologic effect, pozzolanic effect, and micro-aggregate effect [50]. Although being micro-aggregate can enable fly ash to be dispersed well in the mixture, the low hydration degree partially explains the lower compressive strength and surface abrasion resistance ...

Using coal gangue and fly ash as cemented paste backfill materials is a viable solution to address the aforementioned environmental problems [11], [12].Backfill mining can offer support to the overlying strata, limit surface subsidence, and promote solid waste utilization, thereby enhancing the recovery rate [13].Cemented paste backfill with coarse aggregate (CPB …

However, comparing Fig. 12 –1 with Fig. 10 –1 and Fig. 11 –1, it is found that the structure of the former is denser and the large pores reduce more.The spherical structure of fly ash is suitable as micro-aggregate.Fly ash disperses in the hardened cement paste and becomes denser as it is combined with the cement paste for a longer period ...

Natural river sand resources are facing depletion, and large-scale mining pollutes the environment and harms humans. To utilize fly ash fully, this study used low-grade fly ash as a substitute for natural river sand in mortar. This has great potential to alleviate the shortage of natural river sand resources, reduce pollution, and improve the utilization of solid waste …

In this paper, the microaggregate effect of fly ash is studied systematically by micromechanics, the hypothesis of center particle and pore size distribution. It is pointed out …

This paper presents the effect of low density aggregate (LDA) made from fly ash on compressive strength, flexure strength, flexure bond strength, drying shrinkage and shrinkage due to raised temperature for accelerated drying of the micro concrete for concrete repair. Sintered fly ash lightweight aggregate were crushed to required sizes and replaced by weight …

2.2 Fly ash: Fly ash is a residue of combustion processes taking place in power plants and the fine particles are caused due to rise in flue gas. This fly ash due to small size and density is found to in-crease the tensile strength and durability to a greater extent and also has binding properties.

Super-fine grinding can break the out-shell of fly ash beads, releasing the nano-spheres and really improving the active and micro-aggregate effects of fly ash micro-beads.

Effect of high volume fly ash and micro-steel fiber on flexural toughness and durability properties in self-compacting lightweight mortar (SCLM) ... It is also recommended to use short fibers to reduce the brittleness of concrete [46]. With micro steel fibers in lightweight aggregate concrete, the service life can be extended considerably. ...