Hydration Characteristics Research Articles

Hydration characteristics and hydration products of calcium sulfoaluminate cement and fly ash blended pastes

This study investigated a binary blend of calcium sulfoaluminate cement and fly ash with a target compressive strength of more than 32.5 MPa based on the EN 197-1 standard, using as much fly ash as possible. In the binder system of calcium sulfoaluminate cement and fly ash, a decrease in the replacement level of fly ash results in an increase in compressive strength. Mortar with a 40% replacement level of fly ash for calcium sulfoaluminate cement and added gypsum shows 49.41 MPa strength at 28 d. Its hydrates are hydroxy-AFm, ettringite, crystalline aluminum hydroxide, amorphous aluminum hydroxide, strätlingite, and monosulfate. They are attributed to the hydration of ye’elimite, C2S, and C3A in calcium sulfoaluminate cement. The reactivity of fly ash is not observed until 28 d of hydration. The formation of ettringite is the main cause of the gains in compressive strength.

Investigation of alite hydration in the presence of low- and high-silica zeolites

Synthetic zeolites that are obtained from the hydrothermal reaction of NaOH with fly ash have a well-defined pore structure and pozzolanic properties. This work examines the effect of the low-silica (Na-A) and high-silica (ZSM-5) zeolite structure on the kinetics of alite hydration and mineralogical characteristics of the reaction products. The addition of the Na-A and ZSM-5 zeolites reduced the rate of heat release during the hydration reaction, which is typical for commonly used pozzolanic additives. The ZSM-5 zeolite had a much higher Si/Al ratio relative to the Na-A zeolite, which translated into a higher pozzolanic activity and resulted in greater stability of the hydration reaction kinetics. The addition of zeolites caused the heat of hydration to decrease compared to the reference pastes (the alite reference paste—206 J/g): Na-A 15%—148.9 J/g; ZSM-5 15%—149.9 J/g. The concentration of calcium ions in the alite solution and the content of active silica were identified as the most important parameters affecting the kinetic, morphological, and structural characteristics of the C–S–H phase. The addition of zeolites increased the amount of C–S–H gel phases formed. At the same time, the proportion of portlandite in the hydration products of the alite–zeolite systems decreased. Pozzolans reduced the ratio of CaO/SiO2 in the C–S–H phase, which for pastes with the addition of the Na-A ranged from 1.61 to 1.37, and for the ZSM-5 from 1.91 to 0.47. This ratio decreased with the dosage and the age of alite paste. In summary, this research has shown that synthetic zeolites are a viable pozzolanic additives.

Effect of electrolytic manganese residue at different calcination temperatures on hydration characteristics and microstructure of cement mortar

This study investigates the hydration mechanism and microstructure of electrolytic manganese residue (EMR) cement mortar at different calcination temperatures. The results indicate that EMR cement mortar, when calcined at low temperatures (200 and 400 °C), demonstrates improved mechanical properties in the early stages. However, higher sulfate content results in poor setting time and reduced volume stability. Concurrently, there is a notable reduction in the number of gel pores and a considerable increase in capillary pores, leading to diminished mechanical properties in the later stages. Although EMR cement mortar calcined at 600°C exhibits superior mechanical properties, its hydration kinetics are poor. The primary reason for this is that the finer particles of EMR primarily serve a filling role, with no hydration reaction occurring. However, when calcined at 800 °C and 1000 °C, the high-temperature decomposition of dihydrate gypsum forms activated calcium oxide, thereby enhancing pozzolanic activity. Simultaneously, the smaller EMR particles contribute to filling and nucleation, refining the pore structure and enhancing the mechanical properties. Additionally, the incorporation of EMR in cement mortar effectively mitigates heavy metals and achieves the goal of harmlessness.

Methylglyoxal alters collagen fibril nanostiffness and surface potential

Collagen fibrils are fundamental to the mechanical strength and function of biological tissues. However, they are susceptible to changes from non-enzymatic glycation, resulting in the formation of advanced glycation end-products (AGEs) that are not reversible. AGEs accumulate with aging and disease and can adversely impact tissue mechanics and cell-ECM interactions. AGE-crosslinks have been related, on the one hand, to dysregulation of collagen fibril stiffness and damage and, on the other hand, to altered collagen net surface charge as well as impaired cell recognition sites. While prior studies using Kelvin probe force microscopy (KPFM) have shown the effect glycation has on collagen fibril surface potential (i.e., net charge), the combined effect on individual and isolated collagen fibril mechanics, hydration, and surface potential has not been documented. Here, we explore how methylglyoxal (MGO) treatment affects the mechanics and surface potential of individual and isolated collagen fibrils by utilizing atomic force microscopy (AFM) nanoindentation and KPFM. Our results reveal that MGO treatment significantly increases nanostiffness, alters surface potential, and modifies hydration characteristics at the collagen fibril level. These findings underscore the critical impact of AGEs on collagen fibril physicochemical properties, offering insights into pathophysiological mechanical and biochemical alterations with implications for cell mechanotransduction during aging and in diabetes. Statement of SignificanceCollagen fibrils are susceptible to glycation, the irreversible reaction of amino acids with sugars. Glycation affects the mechanical properties and surface chemistry of collagen fibrils with adverse alterations in biological tissue mechanics and cell-ECM interactions. Current research on glycation, at the level of individual collagen fibrils, is sparse and has focused either on collagen fibril mechanics, with contradicting evidence, or surface potential. Here, we utilized a multimodal approach combining Kelvin probe force (KPFM) and atomic force microscopy (AFM) to examine how methylglyoxal glycation induces structural, mechanical, and surface potential changes on the same individual and isolated collagen fibrils. This approach helps inform structure-function relationships at the level of individual collagen fibrils.

Hydrogen storage properties of two-dimensional clathrate hydrates: A theoretical study

In this work, four novel two-dimensional hydrogen hydrates (HH-I, HH-II, HH-III, and HH-IV) were studied by first-principles calculations. The structural characteristics of hydrogen hydrates were analyzed, and their stability and storage capacity were compared. The results show that the confinement effects can greatly increase the storage capacity of hydrogen hydrates, which can reach up to 4.64 wt% for HH-I, 4.76 wt% for HH-II, 3.86 wt% for HH-III, and 3.74 wt% for HH-IV. In addition, adding a small amount of nitrogen can increase the stability of HH-I and HH-IV, but will decrease the stability of HH-II and HH-III.

Effect of phosphorus impurities on sulfoaluminate cement-modified gypsum-based self-leveling mortar and improvement method

The preparation of gypsum-based self-leveling mortar (GSLM) from solid waste-derived sulfoaluminate cement-modified hemihydrate gypsum is an effective path to enhance its mechanical properties. However, the phosphorus impurities in phosphogypsum (PG) still pose a challenge to the hemihydrate gypsum & sulfoaluminate cement composite system. To evaluate the impact of phosphorus impurities and develop targeted removal strategies, this study first assessed the effects of different types of phosphorus impurities on the mechanical properties and hydration characteristics of the GSLM. Then, a method of pretreating PG with carbide slag (CS) was proposed, and the removal efficiency and mechanism of phosphorus were examined by ICP-OES and XPS testing. The results indicated that the soluble phosphorus impurities severely inhibit the hydration of both CŜH0.5 and C4A3Ŝ, leading to a most notable reduced mechanical performance. The sequence of inhibitory action was as follows: H3PO4 >> Ca(H2PO4)2·H2O > CaHPO4·2H2O > Ca3(PO4)2. CS could effectively immobilize the soluble phosphorus in PG. The pretreatment by CS notably enhanced the hydration degree of the GSLM by converting soluble phosphorus into Ca3(PO4)2 beforehand. In addition, the alkaline environment provided by CS promoted the ettringite formation. When the CS content approaches 3%, a PG-based GSLM with good performances meeting the G20 standard requirements of GSLM can be prepared.

PHYSICO-CHEMICAL CHARACTERISTICS OF OSA-STARCH ISOLATED FROM BASMATI RICE AND ITS UTILIZATION IN ETHYLENE GLYCOL PLASTICIZED PVA BLEND FILMS

In the current research, basmati rice starch (BRS) has been modified with octenyl succinic anhydride (OSA). The properties of BRS and modified basmati rice starch (MBRS) were evaluated, and subsequently, the effect of their addition to polyvinyl alcohol (PVA) in two different ratios (70/30 and 30/70) to prepare blend films was studied. The degree of substitution of MBRS was 0.00483%, which was found within the permitted range of Food and Drug Administration guidelines. The pH (6.1 vs. 5.8) and viscosity average molecular weight (1.5 × 104 and 1.275 × 104 Da) were found to be lower for MBRS, solubility (11.52 vs. 13.60%), swelling power (11.5 vs. 13.60 g/g), and oil absorption (2.4 vs. 3.2 g/g) capacities were higher. FTIR and XRD studies revealed minor differences in the MBRS spectra owing to the low substitution. The blend films cast with PVA and MBRS showed higher film thickness, hydration characteristics, transparency, and UV-blocking efficiency.

Molecular dynamics study on hydration characteristics of expansive clay minerals by temperature and inorganic salts

Most strata rock minerals have hydrophilic characteristics and the mineral surface is negatively charged. It can adsorb water molecules to form hydration layers on the mineral surface. The existence of hydration layer will reduce the effective pore diameter of rock pore microchannel. Thus, the development efficiency of crude oil is affected. Hydration layer compared to free water, water molecules are arranged in a highly ordered manner, with higher density and more stable toughness. Therefore, it is very important to study the structure of hydration layer adsorbed on rock wall and its influencing factors. Four different rock and mineral types are selected in this paper: Na-montmorillonite, quartz, kaolinite, calcite. Molecular dynamics method was used to simulate different temperature conditions and adding different inorganic salts. Study the influence of temperature and inorganic salts on the hydration layer structure of rock wall. The simulation results show that the increase of temperature and the addition of inorganic salts of different components have a great influence on the adsorption of water molecules on the rock wall, and it changes the original structure of the hydration layer. The adsorption of water molecules on different rock surfaces and the effect of different rock walls on the adsorption of hydration layer are described in molecular form. This study explains the mechanism of temperature and inorganic salts inhibiting water molecules from a microscopic perspective. It is of great significance to study the physical properties of hydration layer. It provides a theoretical basis for the field well wall stability research.

Influence of CaCO3 on Density and Compressive Strength of Calcium Aluminate Cement-Based Cementitious Materials in Binder Jetting.

We investigated the impact of CaCO3 addition on the density and compressive strength of calcium aluminate cement (CAC)-based cementitious materials in binder jetting additive manufacturing (BJAM). To confirm the formation of a uniform powder bed, we examined the powder flowability and powder bed density for CaCO3 contents ranging from 0 to 20 wt.%. Specifically, powders with avalanche angles between 40.1-45.6° formed a uniform powder bed density with a standard deviation within 1%. Thus, a 3D printing specimen (green body) fabricated via BJAM exhibited dimensional accuracy of less than 1% across the entire plane. Additionally, we measured the hydration characteristics of CAC and the changes in compressive strength over 30 days with the addition of CaCO3. The results indicate that the addition of CaCO3 to CAC-based cementitious materials forms multimodal powders that enhance the density of both the powder bed and the green body. Furthermore, CaCO3 promotes the formation of highly crystalline monocarbonate (C4AcH11) and stable hydrate (C3AH6), effectively inhibiting the conversion of CAC and showing compressive strengths of up to 5.2 MPa. These findings suggest a strong potential for expanding the use of BJAM across various applications, including complex casting molds, cores, catalyst supports, and functional architectural interiors.

Effect of dispersion behavior of silica fume on the rheological properties and early hydration characteristics of ultra-high strength mortar

Silica fume plays a crucial role in ultra-high performance cementitious materials, but its dispersion, influenced by varying densification levels, leads to different degrees of agglomeration. However, the precise impact of this on rheological properties and early hydration characteristics of ultra-high performance cementitious materials remains unclear. This study assesses the impact of highly densified silica fume (HDSF), moderately densified silica fume (MDSF), and raw silica fume (RSF) on the rheological prperties of ultra-high strength mortar (UHSM). Additionally, the early hydration characteristics of UHSM influenced by these silica fumes are investigated through both heat of hydration and penetration resistance methods. The results showed that HDSF contained numerous large agglomerates, contrasting with MDSF and RSF, where the agglomerate sizes were comparable to those of cement particles. As the content of HDSF increased, the yield stress, viscosity, and thixotropy of UHSM gradually rose, accompanied by a notable decrease in hydration rate. Conversely, increasing MDSF and RSF content initially decreased and then increased these rheological properties, while the hydration rate remained relatively unchanged. The distribution behavior of the silica fumes influences the rheological properties of UHSM through water film thickness (particle spacing). Large agglomerates in HDSF reduce the activity of the entire cementitious system, significantly decreasing the hydration rate. In contrast, MDSF and RSF primarily influence the particle spacing within the cementitious system, subsequently impacting the hydration rate. This study provides theoretical insights and practical guidance for construction professionals in selecting appropriate silica fume for designing and regulating ultra-high performance cementitious materials performance.

Effect of anti‐Agglomerants on carbon dioxide hydrate formation in oil–water systems

AbstractThe experiments in high‐pressure pipelines simulate the formation and fluid of hydrate under deep‐sea conditions, which has practical significance for the deep‐sea landfill of carbon dioxide (CO2) and the safe running of oil and gas pipelines. In this paper, pure water, white oil, CO2, and arquad 2C‐75 were used to study the formation and flow characteristics of CO2 hydrate in the oil–water system with the help of a loop device, and the growth morphology of hydrate was observed through the view‐window on the loop. The experimental results show that in the low water cut system without anti‐agglomerates, hydrate mainly forms on the surface of water droplets and the surface of the free water layer at the bottom of the loop. In the high water cut system, hydrate forms on the pipe wall in the form of hydrate film. Increasing water cuts can shorten the induction period of hydrate formation. Anti‐agglomerates in the oil–water system can inhibit the growth of hydrate film on the pipe wall effectively. Anti‐agglomerates can shorten the induction time of hydrate formation.

Hydration characteristics and kinetic analysis of polyacrylamide (PAM) anti-dispersion cement-based materials

Abstract Through phase analysis and quantitative calculations of the hydration process, the inclusion of polyacrylamide (PAM) in Anti-dispersion Water Paste affects its hydration characteristics is discovered. Specifically, the presence of PAM reduces early reactivity while accelerating progress in the middle to late stages of hydration. By employing K-D hydration kinetic analysis, it is confirmed that the use of PAM results in the formation of a multi-nucleation homogeneous point system within the cement slurry. This system prolongs the NG (nucleation and growth) process time, increases the hydration degree during the transition from NG to I (induction) process, and inhibits the heterogeneous precipitation of hydration products. Consequently, the early hydration of cement is hindered. As the hydration reaction advances, the microstructure of the product under multi-nucleation points increases the specific surface area. This gradual breakthrough of the hydration threshold barrier shortens the duration of the phase boundary reaction process and reduces the hydration degree during the I and D (diffusion) processes. Consequently, the late-stage hydration rate is accelerated.

Preface

Abstract This collection includes accepted papers from the 2024 3rd Workshop on Material Science, Modelling, Engineering, and Applications in Vibration Engineering (MVE 2024). With a special focus on material science, MVE 2024 welcome research papers on the relationship between structure, properties, and uses of materials (including metals, ceramics, glasses, polymers, energy materials, electrical materials, composite materials, fibers, nanostructured materials, nanocomposites, and biological and biomedical materials). In MVE 2024, we have received 29 submissions and 17 are accepted after peer review carried out in Morressier online submission system, with 48 reviewers participated. The final acceptance rate is 58%. For cost efficiency and eco-protection considers, the webinar of MVE 2024 (Almaty, Kazakhstan) provides free access to all attendees and audiences through TencentMeeting. The webinar consists three parts, keynote speech by Prof. Muhammad Suyfan Javed, oral speeches and posters. The keynote speech lasts for 30 minutes and each oral speech is assigned with 15 minutes of presentation and 5 minutes for Q&A. The posters are presented on the webinar and the website for further post-webinar communications. Though poster presenters are not able to get instant communication with audience, they are given opportunities to get connected via emails. Among the seventeen papers in the proceedings, five papers, including Hydration characteristics and kinetic analysis of polyacrylamide (PAM) anti-dispersion cement-based materials, Dynamic analysis of a hydraulic motor lifting auxiliary beam of monorail crane, Research of localization of vibration under strong disturbances using modal analysis methods, Research on seismic response and enhanced resistance support of cross fault tunnel models in healthcare, Experimental study on the influence of different sampling methods on the stress-strain and strength characteristics of weathered and water rich sandstone, are presented with oral speeches. The rest papers are all presented with posters. The proceedings editors hope that this collection can provide guidance for problem solving and further studies. List of General Chair and Technical Program Committee are available in this Pdf.

Effects of stepwise depressurisation rate on methane hydrate dissociation dynamics at pore scale using microfluidic experiments

Methane hydrate, recognized as a potential alternative energy source, faces challenges in achieving efficient production. Stepwise depressurisation has emerged as a viable technique for enhancing productivity, yet optimizing the depressurisation rate remains a complex issue. This study employs pore-scale experiments using microfluidic chips to examine the dissociation characteristics of methane hydrate under varying stepwise depressurisation rates. At a high depressurisation rate of 0.4 MPa/15 min, the dissociation process exhibits a three-stage pattern: stabilisation, rapid dissociation, and slow dissociation. During these stages, the mass transfer limitation in the water phase significantly impedes the dissociation rate. The gas-water migration triggered by depressurisation can mitigate this limitation. As the depressurisation rate is reduced to 0.2 MPa/15 min, the rapid dissociation stage splits into two due to a decrease in gas-water migration intensity. The dissociation rate decreases by 45% compared to the 0.4 MPa/15 min case. This results from an insufficient driving force for dissociation, necessitating another depressurisation step. Further reduction of the depressurisation rate to 0.1 MPa/15 min leads to a less pronounced gas-water migration, which is inadequate to significantly counteract the mass transfer limitation. As a result, the rapid dissociation phase occurring at a depressurisation rate of 0.4 MPa/15 min, which exhibits an average dissociation rate of 0.2%/s, subsequently transitions into a more uniform and slower dissociation stage, where the average rate of dissociation declines to below 0.07%/s. The experimental results offer valuable insights for guiding hydrate exploration strategies during the stepwise depressurisation process by adjusting the depressurisation rate to regulate production.

Effect of modified amino acids on hydration behavior of β-hemihydrate phosphogypsum

In practice, it is often necessary to add retarders to β-hemihydrate phosphogypsum (β-HPG) to prolong its setting time. In this paper, the effects of modified amino acid (XK) on physical and mechanical properties, hydration characteristics, and microstructure of β-HPG were investigated using various methods including fluidity, setting time, strength, hydration heat, X-ray diffraction (XRD), scanning electron microscope (SEM), mercury intrusion porosimetry (MIP), and X-ray photoelectron spectroscopy (XPS). The findings indicate that the addition of XK enhances the fluidity of β-HPG, and as the content of XK increases, there is an occurrence of prolonged setting time but a concurrent decrease in both the compressive and flexural strength. In addition, the incorporation of XK hampers the hydration process of β-HPG, resulting in a reduction in the hydration exothermic rate. Microscopic analysis reveals that while XK does not alter the final hydration products, it does affect the growth pattern of dihydrate gypsum crystals because of surface adsorption, and specifically, the crystals become short and columnar, with a looser crystal structure. Furthermore, XK leads to larger pores and deterioration of the pore structure of β-HPG.

Numerical study on decomposition characteristics of natural gas hydrate based on molecular dynamics method

The molecular dynamics method is used to investigate decomposition characteristics of natural gas hydrate under different pressure and salinity. In this paper, the influence of pressure variation on the stability of natural gas hydrate under high pressure is studied from the molecular point of view based on the seabed pressure in Shenhu sea area. At the same time, taking the real marine conditions in the South China Sea as a reference, the effect of the synergistic effect of various salt ions on the decomposition of natural gas hydrate under the effect of salinity is studied. Its decomposition behavior is discussed by analyzing the parameters such as cell conformation, radial distribution function, mean square displacement and self-diffusion coefficient. The results show that pressure and salinity influence the decomposition of natural gas hydrate through modifying stable its conditions, from solid state to gas-liquid state. And the reduction of pressure accelerates the decomposition of natural gas hydrate under high pressure, while the increase of salinity promotes the decomposition of natural gas hydrate under the condition of high salinity.

Effects of airflow superfine pulverization on the structure, functional properties, and flavor quality of wheat bran.

Wheat bran (WB) is a byproduct of refined wheat flour production with poor edible taste and low economic value. Herein, the WB was micronized via airflow superfine pulverization (ASP), and the effects of the ASP conditions on its particle size, nutritive compositions, whiteness, hydration characteristics, moisture distribution, microstructure, cation exchange capacity, volatile flavor components, and other characteristics were investigated. Reducing the rotational speed of the ASP screw and increasing the number of pulverizations significantly decreased the median particle size Dx(50) of WB to a minimum of 12.97 ± 0.19 μm (P < 0.05), increased the soluble dietary fiber content from 55.05 ± 2.94 to 106.86 ± 1.60 mg g-1, and improved the whiteness and water solubility index. In addition, the water holding capacity and oil holding capacity were significantly reduced (P < 0.05), while the cation exchange and swelling capacities first increased and then decreased. Up to about 70% of water in WB exists as bound water. As the Dx(50) of WB decreased, the content of bound and immobile water increased, while the free water decreased from 14.37 ± 1.21% to 7.59 ± 1.03%. Furthermore, WB was micronized and the particles became smaller and more evenly distributed. Using gas chromatography-ion mobility spectrometry, a total of 37 volatile compounds in micronized WB (including 10 aldehydes, 9 esters, 7 alcohols, and several acids, furans, ethers, aldehydes, esters, and alcohols) were identified as the main volatile compounds of WB. Collectively, ASP improved the physicochemical properties of WB. This study provides theoretical references for the use of ASP to improve the utilization and edibility of WB. © 2024 Society of Chemical Industry.

Hydration Characteristics of Slag-Ca(OH)2-Al2O3 Binder in a 60 °C Curing Environment with Brine as Mixing Water

Recently, research results on PC-based or alkali-activated slag cement (AASC) using seawater as mixing water have been reported. Unlike seawater, reverse osmosis brine (brine) is waste discharged into the ocean from seawater desalination plants. There is a need to develop new and effective methods of disposing or utilizing brine to reduce marine pollution, protect marine ecosystems, and increase marine plant construction. However, research on cement or concrete using brine as a mixing water is very limited. Brine has almost the same composition as seawater, and the ion concentration is 2–4 times higher. Therefore, it is believed that new methods of using brine can be investigated and developed based on existing research and experimental results on seawater. The effects of brine and aluminum oxide (AO) on activated slag with calcium hydroxide (CH) were investigated for hydration and mechanical properties. 5% and 10% of CH were used, and samples using fresh water (FC) were prepared at the same time for comparison with brine. The slag sample without CH has a low initial (1 and 3d) strength of about 10 MPa for both FC and brine, but increases rapidly from 7d. Incorporation of CH was effective in improving the mechanical performance of FC and brine samples. In addition, the brine sample exhibited higher strength than the FC sample because it formed fewer C3AH6 phases that cause volume instability than the FC sample and affected the hydration promotion of slag particles. And more calcite phases were observed in the brine samples than in the FC samples. Through this study, the possibility of using brine as a building material was confirmed. In addition, the effect of chloride ion adsorption of slag mixed with AO and CH on the physical properties and mechanical performance of the hydration reaction was confirmed.

Effect of wax on hydrate formation and aggregation characteristics of water-in-oil emulsion

In recent years, the formation and aggregation of wax and hydrate under the condition of coexistence has become a hot spot in the safety assurance of deep-water pipeline flow. In order to clarify the influence mechanism of wax and hydrate in deep-sea crude oil under coexistence conditions, the effects of different wax-containing conditions on the nucleation, growth and aggregation characteristics of hydrate in oil–water emulsion were studied by macroscopic and microscopic experimental equipment. The results show that low wax content (0–3.wt%) provides nucleation sites for hydrate formation and thus promotes hydrate formation. High wax content (>3.wt%) inhibits hydrate formation by preventing water droplets from contacting gas molecules. Low wax content (0–3.wt%) significantly reduces hydrate interparticle aggregation. High wax content (>3.wt%) promotes hydrate interparticle aggregation, which changes the flow characteristics of the hydrate slurry. In addition, through further analysis by PVM and high-speed camera, a wax-containing hydrate aggregation mechanism model was established.

Optimal development of the new type of ultra-fine fly ash semi flexible pavement grouting material: Rheological, mechanical, pore distribution, and hydration characteristics

In order to solve the problems that the fluidity of semi-flexible pavement grouting materials (SFPGM) is not up to standard, the early strength is not enough, or the fluidity meets the requirements but the early strength is not up to standard, the power plant by-Product -ultra-fine fly ash (UFA) was used to optimized the performance of grouting materials (GM) in this study. The microstructure of hardened slurry was analyzed by XRD, FTIR, MIP and SEM. The findings indicate that when the UFA content increases, the fluidity of the GM initially increases and then declines, whereas the compressive strength initially reduces and then increases. The sample exhibits optimal fluidity performance when the content of UFA is 9 %. The flow cone fluidity of the initial and 20 min is 12.33 % and 17.63 % lower than that of the reference sample. When the amount of UFA is 12 %, the compressive strength of sample is the highest at each age. Additionally, that the fluidity of sample S12 is sub-optimal in all samples, only worse than that of sample S9. In the early stage of GM hydration, UFA with slow hydration rate produces a significant ‘ball-bearings effect’ between irregular cement particles. This is beneficial to the relative sliding between the slurry particles, reduces the yield stress and plastic viscosity of the fresh slurry, and improves the flow performance of the GM. The pozzolanic effects of UFA in GM primarily manifests during the later stages of hydration. The primary hydration products of UFA modified GM include ettringite, C-S-H gel, C-A-S-H gel, calcium carbonate, and aluminium glue (AH3). During the progression of the hydration reaction, the quantity of ettringite (AFt) in the slurry steadily augments, causing the initial fine needle-like structure to evolve into a more fully formed needle-like structure. A complex three-dimensional network of interlocking spatial structures is formed by many hydration products that continually interlace and develop, improving strength. The higher the perfusion rate of the GM, the higher the compactness of the SFPGM, and the better the high temperature stability and low temperature crack resistance.