Concrete Mixtures Research Articles

The Effects of the Fineness Level of Rice Husk Ash as a Partial Cement Substitute in Self-Compacting Concrete (SCC)

Rice husk ash (RHA) is recognised as a sustainable mineral additive derived from waste. The substitution of a portion of cement with RHA could improve the mechanical characteristics of concrete, leading to the increased adoption of Self-Compacting Concrete (SCC). The properties of rice husk ash need to satisfy specific criteria to ensure its reactive qualities are fully effective, including the fineness of the husk ash. The quality can be achieved using a filtering technique to obtain the RHA with a certain level of fineness, with division in several zones, 0,1,2,3 and 4. RHA from each zone partially replaces 10% cement in the SCC mixture. To obtain the physical characteristics of SCC, tests were carried out in the fresh phase, which includes slump flow, V-Vunnel, and L-box tests. Meanwhile, compressive strength, flexural strength, and modulus of elasticity tests were conducted to obtain the mechanical properties of the mixture. The results of the fresh concrete test showed that all mixtures are qualified as SCCs, and the results of the hardened concrete test suggested that the fineness of RHA enhances its mechanical properties.

The Recycling Use of Concrete Waste as Aggregate to Produce Different Types of Concrete

The present study depends on two types of concrete: the first and second samples belong to Portland cement with a high strength of 52.5 R, and ordinary Portland cement with a normal strength of 42.5 N, respectively. The physical tests for these two samples according to Iraqi Standard Specification No. 5 of 2019 were conducted. Whereas the third and fourth samples of concrete waste were taken from Mosul City and Al-Anbar Governorate. The concrete waste samples were broken into different-size particles as a fine and coarse aggregate using a mechanical crusher (Los Angeles). According to the Iraqi Standard Specification No. 45 (1984, the Physical and chemical tests for both fine and coarse natural aggregate and recycled concrete waste were conducted. The physical and mechanical results of the recycled aggregate testing samples were found to be within the limits of specifications, in which a reference concrete was made from the standard cement samples with natural aggregate for comparison. The natural aggregate was replaced with 100% recycled aggregate, and its behavior was studied through mechanical properties tests, including compressive strength, flexural resistance, and direct tensile resistance within 7 and 28 days. The results show a decrease in the compressive, flexural, and direct tensile strength in the subjected samples compared to the reference specimens. The study concluded that a 100% replacement ratio of coarse and fine recycled aggregate can be used successfully with different types of cement to obtain a new type of concrete that can be used in several engineering fields. The mechanical properties of the new concrete depend mainly on the type, class and quality of the natural cement even on the properties of the recycled aggregate.

Effect of high-strength SCC with and without steel fibres on the shear behaviour of dry joints in PCSBs

The structural behaviour of precast concrete segmental bridges (PCSBs) heavily relies on the strength of the joints between segments. Multi-keyed dry joints are currently the most commonly used solution in these discontinuity zones. Employing high-strength concrete is becoming increasingly common in civil engineering given its higher strength and improved durability. It specifically allows higher prestressing levels in PCSBs. Using self-compacting concrete enhances workability and adding steel fibres improves mechanical properties. The existing scientific literature includes experimental tests to analyse the shear behaviour of castellated dry joints in different concrete types. However, no experimental tests appear specifically for the castellated dry joints made with high-strength self-compacting concrete (HS-SCC) with and without steel fibres. Therefore, this experimental study conducted 31 push-off-type tests to analyse the behaviour and shear capacity of dry joints made of HS-SCC by investigating the influence of adding steel fibres to the concrete mix. The study examined crack patterns, load-displacement behaviour, failure modes and different (cracking, ultimate and residual) loads. The addition of steel fibres improved joints’ shear capacity. However, brittle behaviour was observed after reaching ultimate load when using HS-SCC, even when steel fibres were added to the concrete mix. Finally, the adequacy of existing formulations was analysed. Standard AASHTO proved to be on the unsafe side for the castellated dry joints specimens made of HS-SCC without steel fibres, and provided a good approximation for the specimens with steel fibres.

The Use of Plastic Waste as Replacement of Coarse Aggregate in Concrete Industry

Recycling solid waste is one of the most important ways to reduce carbon footprints and put sustainability into practice. This research aims to bridge the gap between the results of previous studies and the effectiveness and sustainability benefits of using plastic waste (PW) in concrete mixes by partially replacing coarse aggregate with PW. Furthermore, we examine the suitability of the concrete produced for use as a construction material. The research methodology is based on studying the physical and mechanical behavior of concrete produced by partially replacing coarse aggregate with 0%, 2.5%, 5%, 7.5%, 10%, and 12.5% PW. For the conventional concrete–CC mix of 0% PW, the design strength, fcu, was 35 MP, with a slump of 100 mm, using a water–cement ratio of 0.5, a M.A.S of coarse aggregate of 20 mm, and a sand F.M. of 2.2. According to British standards, BS, slump and density tests were carried out for concrete samples produced in their fresh state and strength tests, ultrasonic testing, etc. for concrete samples after hardening. The results indicated that there is no significant difference between the dry density and bulk density of concrete produced at all its age stages, regardless of the percentage of PW that replaces the aggregate. It also indicated that the compressive strength, the flexural strength, and the splitting tensile strength of the produced concrete decrease steadily and significantly when aggregates are replaced by PW by more than 2.5%. It was found that the decrease in compressive strength does not exceed 1% for concrete with 2.5% PW compared to the strength of CC, while the compressive strength of concrete with 5% PW decreases by 24%. The maximum reduction rate of the flexural strength and splitting tensile strength was 40% and 32%, respectively, for concrete at 12.5% PW compared to the strength of CC. Therefore, PW concrete can retain its strength when used in small quantities of up to 2.5% and can be applied in structural works.

Full-scale testing of the bending behaviour of UHPC gravity–grouted sleeve–prestressed anchor joints in assembled frame tunnels

Joints are weak parts of a prefabricated tunnel frame structure, and the joint bending resistance is a crucial factor controlling the deformation and bearing capacity of the tunnel structure. This study proposes a joint with dual anchoring of ultrahigh-performance concrete (UHPC) gravity-grouted sleeves and prestressed steel reinforcement. The material strain, opening amount, deflection, stiffness, rotation angle, and ductility of the grouted sleeve-prestressed anchor joint and grouted sleeve joint types were tested through full-scale bending tests, and with the help of noncontact measurement technology, the dynamic process of joint bending failure was captured. In addition, the finite element method was used to evaluate the influences of the prestressing magnitude and the position of the prestressing steel bars on the bending performance of the joints. The results indicate that the damage to the concrete joint is concentrated at the top of the joint and that the damage to the top surface of the joint concrete is distributed in an "m" shape, indicating that the damage to the concrete in the area between the sleeves is relatively extensive. Owing to the turning points of grouting material fracture and joint yielding, the joint bending process clearly shows a three-stage change. The grouted sleeve-prestressed anchor joint exhibits greater bending stiffness than the grouted sleeve joint does, and the slip of the grouting material in the sleeve is smaller. Prestressing plays a key role in enhancing the bearing capacity and deformation resistance of joints. Considering that excessive prestress may increase the brittleness of the structure, the prestress of the grouted sleeve-prestressed anchor joint is recommended to be 200 kN. This study provides theoretical support for the joint design and construction of prefabricated tunnel frame structures.

Multi-scale characterization of lightweight aggregate and superabsorbent polymers influence on autogenous shrinkage and microstructure of ultra-high performance concrete

This study investigates the effects of internal curing agents on the autogenous shrinkage, hydration, and microstructure of ultra-high-performance concrete (UHPC). Lightweight aggregate (LWA) and superabsorbent polymers (SAP) were examined across various dosages as representative internal curing agents. Measurements were taken for the mechanical properties, autogenous shrinkage, and internal relative humidity of the UHPC. The mechanisms of internal curing were analyzed using thermogravimetry, pore structure, and microstructural evaluations. Additionally, porosity and microhardness in the matrix around the fibers and internal curing agents were tested to quantitatively assess their impact on the properties of the UHPC matrix. Results indicate that high dosages of LWA or SAP negatively affect the compressive strength of UHPC. A dosage of 15 % LWA increased flexural strength by 11 %, whereas SAP showed no significant improvement in flexural strength. LWA effectively reduced autogenous shrinkage by 49.4 %-88.8 %, while a SAP dosage of 0.3 % reduced autogenous shrinkage by 82 %. Both LWA and SAP increased porosity by 33.9 %-55.9 %. SAP released water within the matrix, forming voids filled with calcium hydroxide. The interface between LWA and the matrix was dense, with porosity near the LWA and SAP interfaces being 23.5 %-53.9 % and 26.0 %-38.2 % lower, respectively, compared to other areas. The microhardness in the LWA and SAP interface regions was 20 % and 16.2 % higher than in different places. The LWA pre-saturated method can effectively reduce autogenous shrinkage, and 15 % LWA has no adverse effect on mechanical strength.

Optimizing concrete strength through the incorporation of steel nails: a comprehensive engineering analysis

The primary materials utilized in contemporary buildings are concrete and reinforced concrete. Researchers applied many methods to improve their quality and reduce costs by adding additives. The primary focus of this investigation is the compressive strength of concrete. After adding varying amounts of steel nails to the concrete mixture, the ensuing changes in compressive strength are subjected to a comprehensive analysis. Mix design was conducted, and concrete cylinders having a diameter of 4” and height of 8” were produced with varying percentages of steel nails: 1%, 2%, 3%, 4%, and 5% of the cement weight. The mixture was prepared, maintaining a constant water-to-cement ratio of 0.5. The compressive strength of the concrete is measured at 3, 7, 14, and 28 days after the mixing process. It was determined that steel nail incorporation increased compressive strength. With a 5% mix, the highest strength measured is 4775 pounds per square inch, much higher than the normal strength required for most construction projects. Furthermore, using steel nails led to a cost reduction in concrete of up to 0.5%, alongside a strength enhancement of up to 24% compared to conventional concrete.

Experimental Study on Lightweight Concrete through Partial Replacement of Cement with Fly Ash and Fine Aggregate with Thermocol

Abstract: Lightweight concrete provides a sustainable way to decrease the weight of structures, improve heat insulation, reduce environmental impact and make buildings more resistant to earthquakes. This research looks at creating lightweight concrete using fly ash (30%, 40%, 50%, and 60%) instead of some cement and thermocol (0.2%, 0.4%, and 0.6%) instead of some fine aggregates. We made 78 cube samples (each 150 mm × 150 mm × 150 mm) and 26 cylindrical samples (150 mm in diameter and 300 mm in height). These samples were made and then kept for different periods before testing. The samples are classified into two groups: one was left for 7 days of curing and the other for 28 days. Each group has three cubes to study how much pressure they could handle and for the cylindrical samples, we tested one from each group to see how much force they could resist. The aim is to make the concrete lighter while maintaining the required strength. Fly ash, which comes from burning coal, makes the concrete easier to work with and more environmentally friendly. Thermocol makes the concrete much lighter and better at insulating heat. The concrete samples were tested for their compressive and tensile strength during testing. The results showed that the concrete became much lighter maintaining the required strength, making it compatible for the desired purpose. By including waste materials such as fly ash and thermocol, this method provides a more environmentally friendly and cheaper alternative to regular cement concrete mixture. The results show that it can cut material costs, reduce CO₂ emissions, and encourage sustainable building practices. This approach of using lightweight concrete significantly contributes to the development of sustainable infrastructure while addressing the growing demand for less environmentally conscious construction practices.

A review paper on performance evaluation of bacteria induced concrete for rigid pavements

Concrete is a foundational material renowned for its performance across a spectrum of applications in construction and infrastructure. it is indispensable in meeting the diverse demands of modern engineering and architecture, from towering skyscrapers to intricate bridges, from residential homes to transportation networks, concrete's performance capabilities have shaped the built environment in profound ways. But conventional concrete is susceptibility to cracking, especially under tensile stresses. This can compromise the structural integrity of concrete elements and lead to durability issues and reduced service life. Rigid pavements are vulnerable to cracking due to temperature changes, shrinkage, and severe loads. Cracks have the potential to undermine the pavement's structural integrity, hastening deterioration and raising maintenance requirements. Review paper describes the method that is used in showing the performance Evaluation of concrete Through the process of carbonate ion formation, a microorganism secretes calcium precipitate externally, forming CaCo3. This fills in the holes in the concrete texture, increasing its compactness. Conversely because of the expansion of the filler fabric inside the concrete mixer's pores, this improves the strength of the concrete. In the laboratory tests has been carried out to study the impact of introducing bacteria on concrete. here compressive strength, flexure strength, split tensile strength and durability test on Bacteria induced Concrete is studied and SEM and XRD analysis is also carried about to the study the microstructure of Bacteria induced concrete.

Investigation of 3D Printed Self-Sensing UHPC Composites Using Graphite and Hybrid Carbon Microfibers

This paper explores the development of 3D-printed self-sensing Ultra-High Performance Concrete (UHPC) by incorporating graphite (G) powder, milled carbon microfiber (MCMF), and chopped carbon microfiber (CCMF) as additives into the UHPC matrix to enhance piezoresistive properties while maintaining workability for 3D printing. Percolation curves were established to identify optimal filler inclusion levels, and a series of compressive tests, including quasi-static cyclic, dynamic cyclic, and monotonic compressive loading, were conducted to evaluate the piezoresistive and mechanical performance of 29 different mix designs. It was found that incorporating G powder improved the conductivity of the UHPC but decreased compressive strength for both mold-cast and 3D-printed specimens. However, incorporating either MCMF or CCMF into the UHPC resulted in the maximum 9.8% and 19.2% increase in compressive strength and Young’s modulus, respectively, compared to the plain UHPC. The hybrid combination of MCMF and CCMF showed particularly effective in enhancing sensing performance, achieving strain linearity over 600 με. The best-preforming specimens (3G250M250CCMF) were fabricated using 3 wt% of G, 0.25 wt% of MCMF, and 0.25 wt% of CCMF, yielding a maximum strain gauge factor of 540, a resolution of 68 με, and an accuracy of 4.5 με under axial compression. The 3D-printed version of the best-performing specimens exhibited slightly diminished piezoresistive and mechanical behaviors compared to their mold-cast counterparts, yielding a maximum strain gauge factor of 410, a resolution of 99 με, and an accuracy of 8.6 με.

Prediction of bond strength between fibers and the matrix in UHPC utilizing machine learning and experimental data

The bond strength between fibers and the matrix plays a crucial role in the tensile strength and post-cracking performance of ultra-high-performance concrete (UHPC). However, existing studies have not attempted to utilize machine learning models for the prediction of bond strength. In this study, machine learning techniques were employed to predict the bond strength of fibers in UHPC. A dataset comprising 658 experimental records was compiled and advanced unsupervised Isolation Forest techniques were utilized to identify and remove outliers, thereby ensuring the accuracy and reliability of the data. Six machine learning models, including ANN, GBDT and XGBoost are utilized in this study, with a focus on evaluating their performance in predicting the maximum pull-out force of fibers. The results indicate that the XGBoost model exhibits exceptional predictive performance, achieving R² value of 0.98, which demonstrates the model's capability to accurately predict the fiber pull-out process. Furthermore, feature importance analysis, visualized through advanced techniques, reveals the significant influence of fiber tensile strength on the pull-out force. A new equation is proposed to predict the maximum pull-out force of fibers and correction factors for different fiber shapes are introduced, significantly enhancing the precision of the calculations. The newly proposed predictive equation has R² value of 0.72, which increases to 0.74, 0.77, and 0.86 after the introduction of shape correction factors, significantly enhancing the accuracy of the computed results. This study not only provides an efficient and reliable method for predicting fiber bond strength in UHPC but also offers an innovative tool for calculating fiber pull-out force.

Revealing the effect of hydroxyethyl methyl cellulose ether on rheological characteristics and hydration kinetics of Ultra-High Performance Concrete with high thixotropy

In this study, the effects of hydroxyethyl methyl cellulose ether (HEMC) content and molecular chain on rheological characteristics and hydration kinetics of Ultra-High Performance Concrete (UHPC) with high thixotropy are detailed investigated. The results showed that with an increase of HEMC content, the air content of UHPC can be increased, and the mechanical properties and durability of UHPC could be simultaneously deteriorated. In addition, although a higher air content may reduce the mechanical properties and durability of UHPC, the added HEMC with longer molecular chain is also helpful to increase the yield stress by 312.2 % and decrease the plastic viscosity by 46.5 % for UHPC slurry, which is important to improve the spray-ability of UHPC. At the same time, the HEMC with short molecular chain can reduce the early autogenous shrinkage of the UHPC by about 30 %, which is also important to improve the volume stability of sprayed Ultra-High Performance Concrete (SUHPC). Therefore, in practice, to develop a SUHPC with advanced properties, the type and content of HEMC should be well chosen by simultaneously considering the requirements of rheological properties, mechanical properties and durability at least.

Experimental study of static and fatigue push-out test on headed stud shear connectors in UHPC composite steel beams

Steel-concrete composite girder bridges utilize shear connectors to connect concrete deck slabs and steel girders. In current practice, the headed shear stud connector is the most used due to its reliability and ease of installation. Several studies are available on the static and fatigue behavior of welded-headed shear studs embedded in normal-strength concrete. However, relatively little is known about the static and fatigue behavior of headed shear connectors in composite beams when shear studs are embedded in ultra-high-performance concrete (UHPC). This study reports a series of pushout results carried out on headed shear connectors embedded in UHPC at pre-fatigue and post-fatigue stages. Six pushout specimens were first tested under static load to collapse. The precast normal-strength concrete slabs in the pushout specimens were reinforced with glass fiber-reinforced polymer (GFRP) bars to promote sustainable construction. This practice, commonly used in Canada, aims to eliminate the corrosion of steel bars caused by de-icing salts used during winter. The results from these tests were used to determine the applied fatigue stress range of another six identical pushout specimens, which were subjected to constant amplitude fatigue loading over 2 million cycles. Results show that the fatigue cycles applied to the specimens prior to testing them to collapse did not alter the failure mode or the crack pattern of the tested specimens. Furthermore, the studied pushout specimens considered 6 different shapes of shear pockets in which the arrangement and spacing of studs were varied. It was found that the studs in a square pocket form yielded a shear capacity of 13.9 % and 16.7 % greater than those for similar studs arranged in a single row-oriented longitudinally and transversally, respectively. The accuracy of the various design formulas specified in design codes in estimating the shear resistance of the tested specimens, as well as empirical formulas proposed to develop load-slip curves of tested specimens, is studied. It was found that the European and Japanese codes significantly underestimated the stud shear capacity, whereas the Canadian code provides a more accurate estimation.

Experimental study of steel single skin, double skin and dual tubes stub columns filled with rubberized concrete

This experimental study investigates the performance of rubberized concrete-filled dual steel tubular (RuCFDST) short columns under concentric compression, addressing a gap in existing literature. While previous studies focused on single- and double-skin circular steel tube stub columns, the specific behavior of RuCFDST columns remains largely unexplored. The study compares RuCFDST columns with rubberized concrete-filled steel tubes (RuCFST) and rubberized concrete-filled double-skin steel tubes (RuCFDSST). A total of eighteen specimens were experimentally tested, which consisted of three single-tube configuration, three double-skin configuration, and twelve dual tube configuration. The investigation covers rubberized concrete preparation, material testing, precise measurements, test setup, and result analysis. Key parameters include rubberized ratio (0 %, 10 %, 20 %, and 30 %) and concrete mix variations. The results provide insights into failure modes, load-shortening behavior, ductility, and strength index, with comparisons to the design predictions based on the European standard EC4. The inclusion of rubberized concrete enhances ductility, while RuCFDST columns show promise in combining sustainability and strength. The study also evaluates design predictions, revealing good agreement for lower rubberized content but indicating deviations for higher ratios, suggesting the need for refined design approaches in such cases.

The Performance of Waste Marble Instead of Coarse Aggregate

Now a days we are faced with an important consumption and a growing need for aggregates because of the growth in industrial production, this situation has led to a fast decrease of available resources. On the other hand, a high volume of marble production has generated a considerable amount of waste materials; almost 70%of this mineral gets wasted in the mining processing and polishing stages which have a serious impact on the environment. The processing waste is dumped and threatening the aquifer. Therefore, it has become necessary to reuse these wastes particularly in the manufacture of concrete products for construction purposes. This experimental study presents the variation in the strength of concrete when replacing aggregates by waste marble from 0% to 100% in steps of 25%, 50%, 75% & 100%. M25 grade of concrete were taken for study of slump value is reducing for more % of replacing the stone dust. The compressive strength of concrete cubes at the age of 7, 14 and 28 days were obtained at room temperature. From test result it was found that the maximum compressive strength is obtained only at 50% replacement of coarse aggregate by waste marble at room temperature. This result gives a clear picture that waste marble can be utilized in concrete mixtures as a good substitute for coarse aggregate giving higher strength.

Experimental Study on the High Temperature Performance of UHPCFST Stub Columns at Different Concrete Age

Fire is one of the serious incidents occurring in the construction phase of Ultra-High Performance Concrete filled steel tubes (UHPCFST) columns, which may cause damage to materials, delays to construction and risk to life. This paper investigates the high temperature performance of UHPCFST columns at different concrete age to simulate the occurrence of fire at construction phase. Axial compression experiments on 24 stub columns are conducted to investigate the effect of temperature levels, age of UHPC on the mechanical response of the UHPCFST columns at different construction stages. The findings reveal that the bearing capacity of the UHPCFST stub columns shows an increase and then a decrease with rising temperatures, and columns of earlier age exhibit a greater increase in fire-resistance bearing capacity. Notably, the load-bearing capacity at room temperature increase with the age of UHPC. At 300 ℃, a marginal increment in capacity correlating with age is observed, whereas at 700 ℃, there is a slight decline. Furthermore, the incorporation of coarse aggregate substantially contributes to the augmentation of load-bearing capabilities across diverse conditions. Meanwhile, a formula for calculating the load bearing capacity and equivalent stress-strain curve of UHPCFST stub columns under elevated temperature at different concrete ages is proposed and validated. This research is expected to provide valuable insights for assessing fire safety and reliability of UHPCFST structure in construction settings.

Study on Structural Behavior of Locally Corroded Steel Tubular Columns Filled by Recycled Aggregate Self-Compacting Concrete

Study on Structural Behavior of Locally Corroded Steel Tubular Columns Filled by Recycled Aggregate Self-Compacting Concrete

Flexural Strength of Structural Beams Cast Using Combined Normal-Weight and Lightweight Concrete Mixtures

Limited investigations have evaluated the potential of using layered sections of normal-weight and lightweight concrete (NWC and LWC) mixtures in structural beams and slabs. The main objective of this paper is to assess the flexural strength properties of layered reinforced concrete (RC) beams, which help conserve natural resources and reduce construction weight. Six RC beams cast with different NWC/LWC combinations are tested to determine the damage patterns, concrete strains, ultimate load, displacements at failure, and ductility. The test results showed that the LWC cast in the tension zone (and up to the neutral axis) has a negligible effect on the beam’s stiffness and ultimate load since the overall behavior remains governed by the yielding of tensile steel reinforcement. Nevertheless, the deflection at failure and ductility seem to gradually curtail when the NWC is partially replaced by LWC at different elevations across the beam’s cross-section. A finite element analysis using ABAQUS software 6.14 is performed, and the results are compared with experimental data for model validation. Such data can be of interest to structural engineers and consultants aiming for optimized design of slabs and beams using layered concrete casting, which helps reduce the overall construction weight while maintaining the structural integrity of members.

Performance of Environmentally Friendly Concrete Containing Fly-Ash and Waste Face Mask Fibers

This work was carried out to explore the potential use of used face masks in concrete to develop sustainable green concrete. In this experimental study, used face masks were cut up, removing the ear stripes and internal nose steel wire, to prepare elongated fibers. These fibers were incorporated in cement fly ash mixtures as an additive to determine the response of M20-grade concrete. The Class F fly ash (FA) was employed as a fractional substitute of cement up to 25% by weight, whereas the addition of face masks occurred at 0%, 0.125%, and 0.25% by volume of concrete. The testing scheme focused on the mechanical and durability characteristics of the cement FA mixtures carried out after 3, 28, and 60 days of curing. The inclusion of FA and face mask fibers reduced the density of concrete specimens. The compressive, splitting tensile, and flexural strengths of mixes were also reduced at an early age; however, the strength characteristics improved at later ages, compared to the control mix. The combination of both materials in concrete mixtures resulted in lower water absorption, lower bulk water sorption, and lower mass loss values against acid attack at later ages. Similarly, the electrical resistance of concrete substantially enhanced by increasing the percentage of both materials. The experimental results demonstrated that processed face masks can be utilized in cement fly ash mixes without significantly compromising the resultant concrete characteristics.

Effects of air content on rheological behavior and segregation of self-compacting concrete

Self-compacting concrete (SCC) offers significant advantages due to its low yield stress and plastic viscosity, yet challenges such as bleeding and segregation can compromise its stability. Maintaining a uniform aggregate distribution is essential to prevent these issues. Air-entraining admixtures (AEA) are often used to introduce air bubbles that enhance SCC's resilience in freeze-thaw conditions and potentially improve stability. This study addresses contradictions in prior research regarding the impact of entrained air on SCC's rheological behavior, experimentally evaluates the effects of varying air content on SCC's workability and segregation resistance, and establishes correlations between rheological characteristics and segregation stability. A comprehensive series of rheological tests, including slump flow diameter, flow time, blocking rate, segregation stability, plastic viscosity, yield stress, and segregation index, was conducted on SCC mixes with different AEA dosages. Regression models revealed significant correlations between air content and both the stability and workability of SCC, with results indicating that optimal AEA levels improve flowability and reduce segregation risks. These findings provide valuable insights into designing stable, high-performance SCC formulations tailored for challenging structural applications.