Types Of Admixtures Research Articles

Experimental studies on strength and workability of mineral admixture modified cement-based fibre-reinforced self-compacting concrete

ABSTRACT Mineral admixtures such as fly ash (FA), ground granulated blast furnace slag (GGBS), metakaolin (MK), and silica fumes (SF) derived from industries are often referred to as secondary cementitious materials, as partial replacements for cement. Also, the use of fibres significantly enhances the flexural behaviour of concrete. Various kinds of literature highlight the performance of concrete with one or two types of admixtures. In this study, an attempt is made to explore the effect of the use of more than two admixtures viz. FA, GGBS and MK as a partial replacement to cement and fibrofor fibre (FF) on workability and strength properties of based Fibre-Reinforced Self-Compacting Concrete (FRSCC). The FF in Self-Compacting Concrete (SCC) is varied from 1.0 to 2.0 kg/cum. The SCC samples are tested for three curing durations. Based on the experimental investigations, the workability of all the mixes is found to be within the EFNARC limits. The variation in the compressive strength of SCC for various fibre dosages is within 10%, after 28 days of the curing period. It is noted that A-10 mix with fibre dosage of 1.0 Kg/cum yielded the highest compressive, split tensile, and flexural strengths after 56 days of curing, as compared to that of all other variations including conventional SCC mix.

Investigation on Key Influencing Factors Affecting Temperature Distribution in Concrete

Concrete is an unavoidable composite material used in buildings and structures. The behavior of concrete under the effect of fire is always critical, causing more structural damage. This research proposes experimental investigation on various factors that affect temperature distribution in concrete when exposed to fire. Water cement ratio, grade of concrete, curing period, type of admixtures, and fibers are the factors taken into consideration. The test was carried out in the temperature range of 100 °C to 600 °C. The temperature was measured at various depths of the specimen and then compared. Results from experiments show that grade of concrete, water-cement ratio, curing period and admixture type significantly influences the temperature distribution in concrete whereas contribution of fiber type is negligible. Comparison of temperature distribution at 25 mm from the bottom of specimen at 600 °C for M20 grade with 0.5 and 0.4 water cement ratio was done. It is found that temperature distribution in concrete goes higher as water cement ratio goes higher. There is an increase of 22.6% of temperature distribution for 0.5 water cement ratio than 0.4. Concrete samples which were cured for 14 days, and 28 days were tested, temperature distribution in concrete cured for 14 days is higher than that cured for 28 days. It is because of the curing time of calcium silicate hydrate (CSH) gel, and it was not fully matured and there was no moisture to finish the hydration process of cement.

Study on the chloride ion binding rate of sulfoaluminate cement mortars containing different mineral admixtures

In this study, the chloride ion (Cl−) binding rate of sulfoaluminate cement (SAC) mortars containing different mineral admixtures was investigated. This is essential to improve the durability of concrete structures in high Cl− environments, especially where they are susceptible to Cl− attack such as coastlines and marine structures. The effects of Cl− concentration, curing age, and the type and amount of mineral admixture on the Cl− binding rate of SAC mortars were analyzed. It was found that the content of water-soluble Cl− in SAC mortars decreased with the increase of curing age, while the Cl− binding ratio increased accordingly, indicating that its resistance to internal Cl− permeation increased. The addition of fly ash (FA) and ground granulated blast furnace slag (GGBS) can significantly improve the Cl− binding rate of SAC mortars, and the Cl− binding rate increases to 46.6% with 20% of FA and 38.7% with 40% of GGBS. The effects of mineral admixtures on the microstructure and phase composition of SAC mortars were further investigated by X-ray diffraction (XRD) analysis. The results showed that the addition of FA and GGBS promoted the formation of C-S-H (calcium silicate hydrate) gels and improved the resistance of SAC mortars to Cl− penetration. On the other hand, the excessive addition of silica fume (SF) decreased the Cl− binding rate, whereas a moderate amount of limestone powder (LP) improved the Cl− binding rate. The study of the Cl− binding rate of SAC mortars can help to evaluate their resistance to Cl− erosion in real projects, thus guiding the optimization of concrete formulations and the improvement of durability.

Influence of mixing protocols on flow retention of one-part alkali activated slag systems

Poor workability and rapid flowability loss are among several challenges hindering the wider acceptance of alkali-activated slag (AAS) (i.e. shrinkage, efflorescence). Several attempts were made to solve this issue, focusing more on selected ingredients, proportions, type and dosage of admixtures, and addition sequence. This study shifted the focus to mixing protocol, highlighting its potential and effects on AAS flow retention considering mixing duration, sequence, and relaxation time. Various one-part AAS mixtures activated by 6 %, 8 %, and 10 % sodium metasilicate were tested. Mixing protocols were applied for 10–90 min, mixing with and without relaxation time. Mini-slump, flowability-loss rate, setting time, the heat of hydration, rheological properties, and compressive strength were evaluated. Changes in hydration products were also examined by XRD, FTIR and TGA. Pearson correlation coefficient and ANOVA were applied to identify the dominant factors. Results reveal the dependency of the optimum mixing protocol on the used activator dosage. A long mixing period with r intervals was more effective for high activator dosages due to the continuous breakdown of formed hydration products' links. Modifying the mixing protocol did not alter the amount of formed hydration products, regardless of the activator dosage. These findings pave the way to understanding the role played by the mixing protocol in mineral hydration for wider in-situ implementation of AAS and the flourishing potential of the ready-mix AAS market.

A descriptive analysis of individually compounded home parenteral nutrition prescriptions provided to adults with chronic intestinal failure

Background & AimsHome Parenteral Nutrition (HPN) prescriptions should be tailored to a patient’s nutritional requirements and comprise of individually compounded regimens (IC-HPN) or standard licensed multi-chamber bags (MCB). There is a paucity of research exploring factors associated with admixture type. This study aimed to evaluate the nutrient composition of adult IC-HPN prescriptions and variance in nutrient dosing, make comparisons with the range of MCB available and dosing recommendations stated in international guidelines. MethodsThis cross-sectional observational study analysed anonymised prescription data for adults under the care of a single home care company in England, commencing IC-HPN after January 2021. ResultsThere were 155 patient prescriptions (245 HPN bags) included, with body weight available in 82 (52.9%) cases. Data were reported for each HPN bag, and summarised as an average daily amount, considering the number of different HPN bags and their daily frequency per patient prescription.A vast range of nutrients were prescribed, with variance in dosing highest for lipid, phosphate, and calcium; with coefficient of variance of 106%, 74% and 67%, respectively. One-hundred-thirty-four (54.7%) bags contained lipid, resulting in variable ratios of lipid to aqueous bags provided weekly.Negligible amounts of at least one electrolyte were prescribed in 93 (38.0%) bags, of which 52 (21.2%) contained < 2 mmol calcium. Compared with MCB (65 bags), IC-HPN bags contained higher amounts of all nutrients, apart from nitrogen and phosphate. Mean sodium intake differed substantially between types of bags (IC-HPN 187.5, SD 100.1 mmol versus MCB 49.1, SD 31.7 mmol, p<0.001). A substantial number of patients received HPN dosages beyond guideline recommendations, with higher amounts of sodium and fluid provided in 41 (50.0%) cases; conversely, lower than recommended dosages were seen in 55 (67.1%) for potassium and 61 (74.4%) for calcium. ConclusionsThis study has demonstrated vast variance in IC-HPN parenteral nutrient dosing, with minimal or an omission of at least one nutrient seen. Further research is needed to explore factors that influence usage of IC-HPN, clinical reasons related to lipid dosing and around the variation in doses prescribed outside of guideline recommendations.

A robust approach for bond strength prediction of mortar using machine learning with SHAP interpretability

Application of machine learning (ML) in predicting mortars bond strength contributes to low experimental cost and high accuracy. This study explores the performance of four ML models—Back Propagation Neural Network (BPNN), Support Vector Regression (SVR), Random Forest (RF), and eXtreme Gradient Boosting (XGBoost)—using 304 experimental data points for training and 76 for testing. Among these, the XGBoost model demonstrated the highest predictive accuracy, with R², MAE, and RMSE values of 0.95, 0.06, and 0.13 in the training set, and 0.94, 0.08, and 0.16 in the testing set, respectively. Compared with traditional models, ML approaches, particularly XGBoost, were more effective in providing reliable predictions of bond strength. SHapley Additive exPlanation (SHAP) show that substrate type, ethylene-vinyl acetate (EVA) content and water to binder ratio W/C have the most remarkable effect on bond strength, while the type of cement and admixture shows the least effect. These findings highlight the potential of ML models in optimizing mortar formulations and improving prediction reliability.

Study of Semi-Adiabatic Temperature Rise Test of Mineral Admixture Concrete

The concrete used in the main structures of subway stations has a high degree of constraint. Consequently, temperature changes and shrinkage during construction frequently lead to significant constraint stress, which can result in structural cracking. Therefore, cement with low hydration heat is commonly used in engineering to reduce the temperature of concrete during its age. Aiming at the problem of hydration and heat release caused by concrete construction, based on the principles of concrete hydration heat release and a numerical analysis method, an optimized semi-adiabatic temperature rise test method has been introduced to investigate concrete temperature rise characteristics with different mineral admixtures. The following conclusions were obtained: The effect of reducing the heat of hydration is related to the content and material properties of different mineral admixtures, but not the type of mineral admixture to be incorporated. The temperature rise performance of four common mineral admixtures is as follows: ① total cooling capacity: limestone powder &gt; slag, fly ash &gt; metakaolin; ② early heat generation rate: metakaolin &gt; slag &gt; fly ash &gt; limestone powder; ③ heat reduction rate in the middle and late periods: metakaolin &gt; limestone powder &gt; fly ash &gt; slag.

Permeability Characteristics of Improved Loess and Prediction Method for Permeability Coefficient

Due to its unique geotechnical properties, loess presents itself as a cost-effective and energy-efficient material for engineering construction, aiding in cost reduction and environmental sustainability. However, to meet engineering specifications, loess often requires enhancement. Evaluating its permeability properties holds significant importance for employing improved loess for construction materials in landfills and artificial water bodies. This study investigates the influence of dry densities, grain size characteristics, grain size distribution, and admixture contents and types on the permeability of improved loess, focusing on the Malan and Lishi loess. The falling head permeability test was conducted to analyze how each factor affects the permeability of the improved loess. The findings indicate that the permeability coefficient decreases with increased dry density and admixture content. Conversely, it demonstrates a linear increase with the average grain size (d50), restricted grain size (d60), and the product of the coefficient of uniformity and coefficient of curvature (Cu × Cc). The primary influencing factor is the type of admixture, followed by Cc and d60. Furthermore, this study developed a predictive model for permeability using a support vector machine (SVM), surpassing the predictive accuracy of linear regression and neural network models. The model provides a robust prediction for the permeability of superior loess material.

The Synergistic Effect of Water Reducer and Water-Repellent Admixture on the Properties of Cement-Based Material

Water reducer and water-repellent admixture are very important in improving the workability and durability of cement-based materials. However, the synergistic effect of the two types of admixtures has not been well investigated. In this study, polycarboxylate ether-based superplasticizer (PCE) and octyltriethoxysilane (OTS) were adopted as water reducer and water-repellent admixture, respectively. Their synergistic effect on the fluidity, compressive strength, and water absorption rate of cement-based materials was investigated. Particularly, the pore structure and hydration state of cement paste were analyzed using 1H Low-Field Nuclear Magnetic Resonance (1H LF NMR). The result showed that the fluidity of cement paste containing different dosages of PCE was reduced by 5–10 mm by incorporating 1% OTS, and the compressive strength at the early age of 3 d of mortar containing high PCE dosage of 0.25% decreased up to 15% by using 1% OTS. In contrast, the compressive strength of mortar containing 0.20% PCE was slightly enhanced by the addition of 1% OTS. 1H LF NMR analysis revealed that the combination of PCE and OTS would increase the pore size and total pore volume of cement paste, and more bleeding water would be generated at high PCE dosage. The intensity-weighted T2 values of the main peak (T2¯) implied that both PCE and OTS produced a retardation effect on cement hydration. However, the water absorption rate decreased by 46.6% despite the increase in pore size and total pore volume. The conflict phenomenon powerfully revealed that the internal hydrophobic treatment by OTS has been successfully achieved. Overall, the combination of 0.20% PCE and 1% OTS exerted a positive synergistic effect in improving the compressive strength and water-repelling ability of cement-based materials, which is meaningful for improving their durability and service life.

Genome wide association study of antioxidant activity in pigeonpea germplasm

Pigeonpea (Cajanus cajan L.) is a nutritious crop with antioxidant potential, making it valuable for health supplements and medicinal products. Pigeonpea seed coat possess a rich source of antioxidant properties, particularly in dark colour seed coat varieties. Recently, antioxidant-based drugs for the prevention and treatment of complex diseases have evoked a great deal of research interest in natural antioxidants. We resolved genomic regions by conducted a genome-wide association study (GWAS) using a high-throughput 62 K SNP “CcSNPnks” genic chip to identify SNP markers associated with antioxidant properties in 287 diverse panel of pigeonpea genotypes. Evaluated their antioxidant activity using a spectrophotometric technique based on ferric ion-reducing antioxidant potential (FRAP) and calculated the gallic acid equivalents (GAE) per 100 g of extract. Significant differences in antioxidant activities were found among genotypes, ranging from 3.27 mg in ICPL-13271 to 16.85 mg in UP 9-I for ferric iron-reducing activity. The GWAS identified four distinct marker trait association (MTA) that exhibit a strong correlation with antioxidant properties. We identified significant marker trait associations with chr 2 (AX-165372487), chr 6 (AX-165348296) code for RGA1 protein, chr 10 (AX-165367685) codes for alkaline ceramidase (transcript variant), and chr 11 (AX-165411944) codes for (DL)-glycerol-3-phosphatase 2. The identified protein, RGA1, is involved in reducing ROS accumulation in response to stress by up-regulating the transcription of superoxide dismutases. It suppresses GA-induced vegetative growth and floral initiation. Rapidly degraded in response to GA and involved in fruit and flower development. Furthermore, the population structure analysis identified four distinct sub-populations with admixture types, effectively grouping all genotypes based on their ancestry. Our findings advance the understanding of the genetic underpinning antioxidant concentrations, holding potential for applications in crop breeding and aligning with consumer preferences. This study provides a cornerstone for future research into exploiting marker-assisted breeding to produce pigeonpea cultivars.

Preparation and properties of ultra-high performance concrete incorporation multi-mineral admixtures

Abstract The impact of multi-mineral admixtures on the sturdiness of ultra-high performance concrete (UHPC). In this study on the premise that multi-mineral admixtures can be utilized in UHPC, we optimized the percentage of three admixtures(limestone powder,slag, and pumice powder) that can replace cement using the Box-Behken design response surface method, and prepared UHPC specimens with multi-mineral admixtures. The rationality of the multi-mineral admixtures approach proposed in this study was confirmed by characterizing the mechanical properties and porosity of the prepared specimens. Durability was also investigated through relevant tests. The results showed that the porosity of the prepared UHPC decreased by 49.4%, the mechanical properties improved by 14.7%, the self-shrinkage and drying shrinkage decreased by 9.8% and 6.2%, respectively, and the volume stability improved. Moreover the resistance to sulfate dry-wet cycling, chloride ion permeation, and carbonization improved significantly. This study, thus, demonstrates a new type of multi-mineral admixture for UHPC with excellent mechanical properties and durability.

“Advancements in Lightweight Concrete: A Comprehensive Review”

Abstract: Lightweight concrete (LWC) has garnered considerable attention in recent years due to its advantageous properties such as reduced density, improved thermal insulation, and enhanced sustainability. This review paper provides a comprehensive overview of the advancements, properties, production methods, applications, and future prospects of lightweight concrete. It covers various types of lightweight aggregates, admixtures, and innovative techniques employed in the production of lightweight concrete. Furthermore, it discusses the mechanical, thermal, and durability properties of LWC and compares them with conventional concrete. The review also explores the wide range of applications of lightweight concrete in construction projects and its contribution to sustainable development goals. Finally, it identifies current challenges and future research directions in the field of lightweight concrete.

Atomistic Insight on Effect of Silica Fume on Intermolecular Interactions between Poly(carboxylate) Superplasticizer and Calcium Ions in Concrete.

Understanding how poly(carboxylate)s of chemical admixtures interact with calcium ions in cement pore solutions in the presence of silica fume is fundamental to developing better chemical admixtures for concrete production. In this work, the intermolecular interactions of calcium ions with a poly(carboxylate) superplasticizer type of chemical admixture was investigated via classical all-atom molecular dynamics (MD) simulations and Density Functional Theory (DFT) calculation methods in the presence of silica fume. The classical all-atom MD simulation and DFT calculation results indicate that calcium ions are interacting with oxygen atoms of the carboxylate group of PCE. The better interaction energy could mean an improved adsorption of the PCE segment with calcium ions. In this regard, it can be noted that the ester-based PCE segment could have a better adsorption onto calcium ions in comparison with the ether-based PCE segment. Moreover, the presence of silicon dioxide could improve the adsorption of the PCE segment onto calcium ions.

Sustainable Reclaimed Asphalt Emulsified Granular Mixture for Pavement Base Stabilization: Prediction of Mechanical Behavior Based on Repeated Load Triaxial Tests

The stabilization of asphalt pavement bases with granular soil and aggregates emulsified with asphalt is a widely used technique in road construction and maintenance. It aims to improve the mechanical properties and durability of the lower pavement layers. Currently, there is no consensus on the most suitable method for designing emulsified granular aggregates with reclaimed asphalt pavement (RAP), as it is very complex. Therefore, the methodology is generally based on compliance with one or more volumetric or mechanical parameters established in the highway regulations for conventional asphalt mixtures, which does not guarantee the optimization and characterization of the recycled mixture in the base course. In this study, granular mixtures were developed, including five with emulsion and one emulsion-free as a control mix. Granular RAP mixes were designed in this study, including five with emulsion and one emulsion-free as a control mix. The five mixes ranged from 1% to 5% emulsion and were characterized by multi-stage triaxial tests with repeated load resilient modulus (RM) and permanent deformation (PD) to evaluate their mechanical behavior. The results showed that the mixes had RM values between 350 and 500 MPa, consistent with literature values. However, they showed similar levels of accumulated deformation to the control mix without RAP emulsion. The sample with 1 % RAP emulsion exhibited a satisfactory RM value and better performance in PD than the control mix (5 mm) and showed accumulated PD values of up to 4 mm. In contrast, the other samples exhibited deformations of up to 6 mm. In this study, the multi-stagge triaxial RM and PD tests were found to be an effective predictive method for characterizing the behavior of RAP materials in base courses, regardless of the types of admixtures contained. Multi-stage resilient modulus and PD tests can be considered as a predictive method for the behavior of milled material in base courses. They were able to provide initial data for interpreting the behavior of ETB mixtures.

Leaching-induced deterioration of shear bonding strength and micro-Vickers hardness of the ITZ modified by micro-SiO2 and nano-SiO2

The interfacial transition zone (ITZ) serves as a critical juncture between aggregate and cement paste in concrete, particularly vulnerable to calcium leaching. This study investigates the impact of water-cement (w/c) ratio and micro-SiO2 and nano-SiO2 content on the deterioration of shear bonding strength and micro-Vickers hardness of the ITZ during leaching. Analysis of ITZ micro-structure and elemental composition is conducted using backscattering electron microscope and energy dispersive spectroscopy (BSEM/EDS), and a deterioration model for the shear bonding strength of the leached ITZ is established. Results indicate that during leaching, shear bonding strength and micro-Vickers hardness of the ITZ are approximately 28 % and 67 % of those of the cement paste, respectively. A linear relationship between the shear bonding strength of the ITZ and its micro-Vickers hardness is observed when employing the same type of admixture. Mechanical properties and leaching resistance of the ITZ diminish progressively with increasing w/c ratio. Conversely, they exhibit an initial enhancement followed by decline with increasing micro-SiO2 and nano-SiO2 contents, with optimal contents of 8 % and 2 %, respectively. Micro-SiO2 and nano-SiO2 are found to enhance long- and short-term leaching resistance of cement-based materials, respectively. Additionally, the shear bonding strength of the ITZ decreases linearly with increased degree of area leaching. These findings enhance our understanding of the deterioration behavior of the ITZ and provide an important foundation for studying the durability changes of concrete subjected to calcium leaching.

Progress in process parameters and mechanism research of polymer emulsion preparation.

As a new type of concrete admixture, polymer emulsion is mainly used to strengthen the properties of concrete by adhesion and physical and chemical crosslinking with cement in concrete. Under the background of construction in the new era, it is of great significance to elucidate all aspects of concrete performance under the action of polymer emulsion. In this paper, the main formation process of polymer emulsion is reviewed, the influence of synthetic materials required for polymerization on the polymerization process is discussed, and the regulating effects of reaction temperature, reaction time, admixtures, and treatment methods on the synthesis process of polymer emulsion are analyzed. The action mechanism of polymer emulsion on concrete was deeply investigated, and the synthesis method was studied to provide an important experimental and theoretical basis for the preparation of new emulsion materials and the process of emulsion polymerization. The problems of polymer emulsion raw materials, synthetic conditions, and synthetic methods are introduced. The future development trend of polymer emulsion is predicted and the future research ideas are put forward.

Development of Sustainable Slag-based Geopolymer Concrete Using Different Types of Chemical Admixtures

Geopolymer concrete (GPC) has achieved a wide popularity since innovating it as an alternative to conventional concrete because of its superior mechanical characteristics and durability, in addition to being a green concrete due to its low negative impact on the environment. However, GPC still suffers from the problem of its poor workability which suppresses its spread in construction applications. This study investigated the most effective parameters on the workability of GPC including GGBFS content, water to binder ratio, and dosage of different types of chemical admixtures, Naphthalene-Based Admixture (NPA) and Polycarboxylate-Based Admixture (PCA), using Taguchi approach and Analysis of Variance (ANOVA) analysis considering the compressive strength at the different concrete ages. It was observed that NPA, in the geopolymer concrete, improved the compressive strength compared to PCA. The NPA-based mixes achieved the highest 28-day compressive strength, 69 MPa, with about 27.8% more than the highest 28-day compressive strength achieved by the PCA-based mixes, 54 MPa. The obtained results revealed that the NPA has achieved the best improvement for both the workability, in terms of initial slump value and slump loss rate, and the compressive strength of GPC mixes compared to PCA.

Alkalinity Regulation and Optimization of Cementitious Materials Used in Ecological Porous Concrete.

Ecological porous concrete (EPC) is one of the novel formulations of concrete with unique phytogenic properties. However, achieving both low alkalinity and high strength in EPC proves challenging due to the inherently high alkalinity of the pore environment, which hinders the growth of the plant and affects its ecological benefits significantly. This research investigated the utilization of 15 types of chemical admixtures and diatomaceous earth as alkali-reducing agents to optimize the properties of silicate cementitious materials for the applications of EPC. To identify the most effective agents, the pH value and compressive strength of the cement paste were adopted as the screening criteria for the selection of the essential alkali-reducing ingredients. Subsequently, a composite approach combining chemical admixtures and DE was employed to explore the synergistic effects on the pH and strength of silicate cementitious materials. The results revealed that a combination of 8% DE, 5% oxalic acid, and 5% iron sulfate functioned effectively and resulted in desirable performance for the concrete. This synergistic blend effectively consumed a large amount of Ca(OH)2, reducing the pH of cement paste to 10.48 within 3 days. Furthermore, the hydration reaction generated C-S-H with a low Ca/Si ratio, leading to a remarkable increase in the compressive strength of the concrete, reaching 89.7 MPa after 56 days. This composite approach ensured both low alkalinity and high strength in silicate cementitious materials, providing a theoretical basis for the application and promotion of EPC in the ecological field.

Comparative Study of the Performance of Underwater Concrete between Anionic and Nonionic Anti-Washout Admixtures

An investigation was carried out to study the influence of two types of anti-washout admixtures (AWAs) on the performance of underwater concrete, specifically, workability and washout resistance. The tested AWAs were hydroxypropyl methylcellulose (HPMC) and polyacrylamide (PAM) as nonionic AWAs and carboxymethyl starch (CMS) and polyanionic cellulose (PAC) as anionic AWAs. Rheological properties (slump and slump flow), washout resistance, and compressive strength were measured to evaluate the properties of the fresh and hardened concrete. The results indicate that anionic AWAs are more effective at improving workability and strength than nonionic AWAs in anti-washout underwater concrete. When the nonionic AWA dosage exceeded 0.3% (W/C = 0.45), the fluidity and air content were negatively impacted. Additionally, nonionic AWAs more readily alter the morphological structure of cement paste, affecting cement particle hydration and underwater concrete properties. Regarding the mechanical properties, compared with those of concrete without AWAs and with nonionic AWAs, the 28-day compressive strength of concrete with anionic AWAs reached 37 MPa, an increase of 151% and 131%, respectively. Compared with nonionic AWAs, concrete with anionic AWAs is more stable.

Study on the effect of double mineral admixtures on the properties of high water materials

In this paper, different contents of fly ash, silica fume, slag, and Nano-SiO2 were added to the high water material. Then, fly ash-silica fume, slag-silica fume, and Nano SiO2-silica fume are mixed into the high water material. Through the strength test of two groups of specimens, the influence of different types of mineral admixtures and blending ratios on the physical and mechanical properties of high-water materials was studied. The mechanical parameters of high water doped materials were measured by ultrasonic method, and the internal pore structure of high water doped materials was analyzed. In the case of double mixing, the optimal mixing amount is 4% fly ash and 6% silica fume, and the 7 d compressive strength of this group of specimens is increased by 15.85% compared with the original high water material. Through ultrasonic detection, the first wave is smooth and stable, the longitudinal wave amplitude curve is flat, the peak difference is slight, and the periodic amplitude is uniform, indicating that the structure of this group of specimens is dense. The shear modulus is increased by 20.31%, Young’s modulus is 1.3 times, and the volume modulus is 8.9 times that of the original high water material. The research findings suggest that high water materials can be modified by double mixing.