Slump Cone Test Research Articles

An investigation of the rheological parameters of slurry composed of ordinary Portland cement, Portland pozzolana cement and Portland slag cement

ABSTRACT This paper compares the rheological parameters of ordinary Portland cement of grade 43 (OPC 43), ordinary Portland cement of grade 53 (OPC 53), Portland pozzolana cement (PPC) and Portland Slag Cement (PSC) to study the thixotropic built. Five slurries with increasing water/cement (w/c) ratios from 0.52 to 0.6 were prepared and examined at resting times of 1 minute, 5 minutes and 10 minutes. Static shear stress (τs), dynamic shear stress (τd) and thixotropic index (β) were studied to analyze the thixotropic built of the slurries. The rheological parameters increase for all the mixes with decreasing w/c ratios and increasing resting times. However, for a w/c ratio greater than 0.60, all the mixes lose their plastic viscosity and the rheological parameters approach non-significant values. The τs and τd values for PPC and PSC pastes are higher than those of the OPC pastes because of the increase in cement fineness and increased rate of structuration and hydration. OPC 53 paste shows high β because of the large extent of reversible thixotropic built. The τs values obtained from the viscometrical tests were then compared the mini slump test values. Results show that the rheological parameters are more consistent than the flow values of the mini slump cone test.

Suitability of using mussel shells as partial replacement of aggregates in self-compacting concrete

Abstract The handling of mussel shell wastes in coastal regions presents an issue that may be addressed by using mussel shells as a construction material. Shells from waste mussels replace aggregate in concrete, whole or in part. The shells of the mussels are well suited to be incorporated as aggregate into a concrete mix since they are primarily composed of limestone, a substance similar to the other ingredients in concrete. The current study focuses on the suitability of using mussel shells to replace aggregates in self-compacting concrete (SCC). The aggregates were substituted with mussel shells in 5, 10, 15, and 20 percentages. The mixes were initially tested for workability, including slump cone test, L-box test, flow test, and V-funnel test, followed by determining the mechanical behavior, such as flexural strength (FS), compressive strength (CS), and split tensile strength (STS). Also, the microstructural analysis of the mixes was done using scanning electron microscopy (SEM) and energy dispersive x-ray (EDX). The results showed that the concrete’s fresh, hardened, and microstructural properties could be improved by substituting aggregates with mussel shells up to 15%. Some prime results of the SCC mix exhibited a slump flow value range of 600–700 mm, a V-funnel flow time of 10–13 sec, an L-box test ratio greater than 0.8, CS of 41.97–52.93 MPa, STS of 3.69–4.18 MPa, and FS of 3.75–4.28 MPa. The study concludes that better-performed SCC can be produced at an optimum dosage of 15% mussel shells to partially replace aggregates.

Mechanical and microstructural characterization of sustainable concrete containing recycled concrete and waste rubber tire fiber

The production of cement, which is the key ingredient of concrete, leads to environmental pollution by releasing massive amounts of CO2 and using significant natural resources. Therefore, shifting towards sustainable and greener materials is essential for mitigating these challenges. In this study, recycled concrete powder (RCP) was used as a cement replacement (0%, 5.0%, 10%, and 15%), solving the waste dumps issue and promoting sustainability. Furthermore, the concrete is also reinforced with steel fibers which were obtained from waste rubber tires to improve concrete tensile strength. The concrete properties were evaluated through slump cone test, compressive strength, failure patterns, tensile strength, scanning electronic microscopy, and FTIR analysis. The results indicate that the concrete strength properties improved with the substitution of RCP. The compressive and tensile strength of the optimum mix (10% RCP and 2.0% addition of steel fibers) are 15.8% and 23% more than those of reference concrete. However, the concrete flow is adversely impacted due to RCP angular particle shapes. Failure patterns indicate that RCP and steel fibers improved concrete ductility. SEM and FTIR analysis indicate microstructural improvement with RCP and steel fibers. Finally, the analysis concluded that the developed concrete showed better performance, solved waste dumps issues, and promoted sustainability.

Flexural strength of recycled aggregate concrete reinforced with nylon fibers

The effect of binary blending of recycled aggregates and nylon fibers on the workability and flexural strength of concrete has been investigated in this work. An equal dosage of recycled aggregates from demolished wastes and conventional aggregates was used with 0.5 water cement ratio in preparing a mix of 1:2:4. Nylon fibers were used from 0% to 2% with an increment of 0.25% by weight of cement to reinforce the concrete. The slump cone test was determined for all nine batches of the concrete. Workability was observed to reduce with an increase in the content of nylon fibers. Flexural strength was evaluated by testing three prism specimens of 150mm x 150mm x 500mm size in each batch. A comparison of test results with control concrete (0% nylon fibers) and recycled aggregate concrete (with 50% recycled aggregates and without fibers) showed that nylon fibers helped in overcoming the loss of flexural strength due to the addition of recycled aggregates. The optimum dosage was recorded as equal to 1.5% with an increase in strength equal to 19.13% and 52.45% in comparison to conventional and recycled aggregate concrete.

A Review on Engineering Behaviour of Sustainable Concrete with Steel Mill Scale and the Effect of Admixture on Workability Improvement

Abstract: The integration of chemical admixtures and alternative materials in concrete production has become a focal point in advancing construction technologies. This study investigates the combined effects of superplasticizers and mill scale on the workability and compressive strength of M30 grade concrete. Three different superplasticizers—Auramix 200, SikaPlast®-3069 NS, and Master Polyheed 8126—are evaluated for their performance enhancements in concrete. Additionally, mill scale, an industrial by-product, is utilized to partially replace sand in varying proportions (0%, 20%, 40%, 60%, 80%, and 100%) to assess its viability as a sustainable aggregate alternative. The experimental phase is divided into three stages: initially assessing the workability and compressive strength of M30 concrete without admixtures; subsequently incorporating mill scale to observe its effect on concrete properties; and finally combining mill scale with each superplasticizer to maintain workability while evaluating the compressive strength. Slump cone tests are conducted to measure workability, and compressive strength tests are performed at 7, 14, and 28 days. Results indicate that the inclusion of superplasticizers significantly enhances workability, with Auramix 200 showing the highest improvement. The addition of mill scale up to 60% replacement level increases compressive strength, with a notable peak at 60% replacement for both plain and superplasticizer mixes. However, higher replacement levels (80% and 100%) result in reduced strength and workability. Among the superplasticizers, Auramix 200 exhibits the best overall performance in conjunction with mill scale. This study concludes that the strategic use of superplasticizers and mill scale can produce high-performance, sustainable concrete. Future research should explore long-term durability aspects and optimize mix designs for broader applications in construction

Engineering Behaviour of Sustainable Concrete with Steel Mill Scale and the Effect of Admixture on Workability Improvement

Abstract: The integration of chemical admixtures and alternative materials in concrete production has become a focal point in advancing construction technologies. This study investigates the combined effects of superplasticizers and mill scale on the workability and compressive strength of M30 grade concrete. Three different superplasticizers—Auramix 200, SikaPlast®-3069 NS, and Master Polyheed 8126—are evaluated for their performance enhancements in concrete. Additionally, mill scale, an industrial by-product, is utilized to partially replace sand in varying proportions (0%, 20%, 40%, 60%, 80%, and 100%) to assess its viability as a sustainable aggregate alternative. The experimental phase is divided into three stages: initially assessing the workability and compressive strength of M30 concrete without admixtures; subsequently incorporating mill scale to observe its effect on concrete properties; and finally combining mill scale with each superplasticizer to maintain workability while evaluating the compressive strength. Slump cone tests are conducted to measure workability, and compressive strength tests are performed at 7, 14, and 28 days. Results indicate that the inclusion of superplasticizers significantly enhances workability, with Auramix 200 showing the highest improvement. The addition of mill scales up to 60% replacement level increases compressive strength, with a notable peak at 60% replacement for both plain and superplasticizer mixes. However, higher replacement levels (80% and 100%) result in reduced strength and workability. Among the superplasticizers, Auramix 200 exhibits the best overall performance in conjunction with mill scale. This study concludes that the strategic use of superplasticizers and mill scale can produce high-performance, sustainable concrete. Future research should explore long-term durability aspects and optimize mix designs for broader applications in construction.

Analysis of Pile Foundation for Hospital Buildings

Pile foundations are widely employed to provide support for bridges and various structures, ensuring the safe transfer of structural loads to the ground while preventing excessive settlement or lateral movement. They excel in transferring structural loads from weaker or compressible soil layers to the stronger, more stable soils and rocks beneath. Pile foundations constitute an integral component of a structure.  In this research work the foundation of the hospital (G+6) was design by the pile foundation. We have used M25 grade of concrete for the preparation of design mix. The characteristic strength and load bearing of soil was tested by Plate load test and other materials tested by slump cone test , aggregate Impact Value test cement compressive strength test (cement fineness test construction water PH value . The expected result of SBC is 20000kg approximate.  Project reports typically encompass introductions and problem definitions, along with literature reviews pertinent to the project. They detail the study area's location and the project site, as well as providing concise information about the equipment utilized on- site.  Additionally, it covers crucial tasks such as centerline marking, boring, reinforcement placement, concrete pouring, excavation, and chipping of pile caps.

Exploring the impact of red mud on the mechanical, durability, and microstructure properties of concrete

Purpose This study investigated the potential of partially replacing cement with red mud (RM) in concrete and examined its effects on its mechanical properties and microstructure. This study aims to explore sustainable alternatives to traditional cement and evaluate the performance of concrete mixtures with varying percentages (%) of RM as cement replacement. Design/methodology/approach This research aims to comprehensively understand the impact of RM on concrete, aiming for both environmental sustainability and improved construction materials. Subsequently, concrete mixtures were prepared with varying RM contents, ranging from 0% to 21% in increments of 3%, replacing cement. The workability of these mixtures was evaluated using the Slump Cone Test, whereas their mechanical properties (compressive strength, flexural strength and split tensile strength) were assessed through standardized tests. The durability was further investigated via water absorption, acid attack, rapid chloride permeability tests, open porosity test and Sorptivity test. To gain deeper insights into the internal structure of concrete, microstructure analysis was conducted using X-ray diffraction and scanning electron microscopy. Finally, the results were analyzed and quantified. Findings The finding demonstrates that substituting 12% of cement with RM not only boosts the mechanical characteristics of concrete but also mitigates waste disposal. The microstructural analysis identified a denser cement matrix and improved bonding between the cement paste and the aggregates, suggesting potential improvements in strength and durability. Originality/value These results suggest that RM can be efficiently used to produce sustainable concrete with potential applications in construction projects with environmental considerations.

Workability and strength of recycled aggregate concrete reinforced with nylon fibers

The demolishing waste generated due to demolishing of the structures has proved difficult to handle due to scarcity of the dumping space particularly in urban areas. Its use in new concrete solves the problem to some extent but developed products differ in properties both at fresh and hardened states. To overcome the deficiency nylon fibers are proposed in this work. The compressive and tensile strength of the proposed concrete at a hardened state and workability as fresh properties of concrete are studied. Conventional and recycled aggregates were used in equal proportions. Nylon fibers of 1 mm diameter and 25 mm length were used from 0.25% to 2% with a 0.25% increment in each successive batch were used. Using 1:2:4 mix with water cement ratio equal to 0.5, a total of 10 mixes were designed. The workability of each mix was evaluated by the slump cone test. Water curing for 28 days was used for five samples in each batch. Compressive and tensile strength were computed from the crushing load determined in the universal testing machine. Comparison of the results with those of control concrete revealed that 1.5% of nylon fibers along with 50% recycled aggregates produce maximum compressive strength of 930.16 (MPa) with 24% more than conventional concrete (24.16 MPa) and 56% more than recycled aggregate concrete (19.27 MPa) without nylon fibers. The tensile strength of the proposed concrete (3.66 MPa) was noticed 22% and 55% higher than the conventional concrete (3.0 MPa) and recycled aggregate concrete (2.36 MPa) at optimum dosage. Hence the impact of optimized doze of the nylon fiber shows improved strength properties of the concrete.

Experimenting with the Utilization of Recron3S Fiber and Steel Slag in Fresh Concrete for Analysis

Abstract: Concrete is well-known for being the most frequently utilized construction material due to its affordability, longevity, and adaptability. However, traditional concrete production requires a large amount of cement and aggregate, raising concerns about its environmental impact and depletion of natural resources. In order to address these issues and promote sustainability, we have been exploring alternative materials like Recron3s polyester fiber and steel slag. Recron3s fiber can enhance the flexibility of concrete, making it a valuable addition. On the other hand, the steel industry generates a byproduct known as steel slag, which presents environmental challenges and disposal issues. Nonetheless, when incorporated into concrete, steel slag can improve the mechanical and physical properties of the material, increasing its durability. Our research focuses on replacing OPC 53 grade cement and natural aggregate with Recron3s fiber and steel slag aggregate, respectively. Different percentages of steel slag aggregate (0%, 20%, 25%, 30%) and Recron3s fiber (0%, 1.25%) were used as substitutes for traditional materials in M30 grade concrete with a water-cement ratio of 0.44. We created concrete mixes by partially replacing OPC 53 with Recron3s fiber and substituting natural aggregate with steel slag aggregate to evaluate the performance of eco-friendly concrete. We then evaluated the performance of these mixes through workability tests such as slump cone, vee-bee consistometer, and compaction factor test. Overall, incorporating Recron3s fiber and steel slag aggregate into concrete has yielded positive results in enhancing mechanical properties and reducing environmental impact.

An Experimental Investigation on Self-Healing Concrete Made of Bacteria with Varying Doses

Abstract: The employment of carbonate-producing bacteria as a new approach to enhance the qualities of concrete has attracted a lot of interest since it is thought to be innocuous to theenvironment, natural, and maybe advantageous. This is a result of the favorable implications attached to these traits. The use of microbially induced carbonate precipitation as a remedy for several problems affecting concrete, such as fracture healing, reduction and change of porosity and permeability, and more, has been the subject of much investigation. Concrete crack healing is one of the topics that have been researched. Additionally, it has been shown that the procedure of bacterial carbonate precipitation, also known as bio deposition, contributes to the development of concrete's compressive strength. There has not yet been a thorough investigation of the research relating to the appropriate bacterial solution dose and its effect on concrete durability. This might occur as a result of the project not receiving enough time to complete it. As a result, it has been decided that an investigation will be conducted in order to determine the proper quantities of bacterial solution required for concrete. To do this, several concrete cube samples will be made using varying amounts of bacterial solution, such as 15 ml, 30 ml, 45 ml, 60 ml, and 75 ml, respectively. These quantities will be added to the appropriate moulds. This will allow you to determine the proper dosage of the bacterial solution to employ. In order to determine the optimal dosage that should be used, these various samples are also put through a battery of tests using a variety of laboratory techniques, such as the properties of materials, slump cone test, a compressive strength testing machine, an ultrasonic pulse velocity test, plate count cells, and scanning electron microscopes, Rapid Chloride Penetration Test (RCPT), Acid attack test.

Investigation into the Effects of Crystalline Admixtures and Coatings on the Properties of Self-Healing Concrete.

One fascinating concept for enhancing the durability and lifespan of concrete buildings involves the use of self-healing concrete. This study focuses on the effect of crystalline admixtures and coatings on various properties of self-healing concrete and provides a comparison with traditional concrete. Four different concrete mixtures were prepared to assess their effectiveness in bridging crack openings, their flexural and compressive strengths, and water absorption. Various testing methods, including destructive, semi-destructive, and non-destructive tests, were used in this research. The capacity of the mixes to repair themselves was assessed on the destroyed and semi-destroyed test specimens using crack-healing and microstructure testing. Additionally, all mixtures were also subjected to the slump cone test and air content test in order to investigate the characteristics of the concrete in its fresh state. The findings demonstrate that crystalline coating and admixture combinations have significant potential for healing concrete. The compressive and bending strengths of self-healing concrete mixtures were shown to be slightly higher compared to traditional concrete when the additive dose was increased. Self-healing concrete mixtures also exhibited much lower water absorption, a tightly packed and improved microstructure, and signs of healed gaps, all of which indicate greater durability.

A comparative study between linear regression analysis and various codes for predicting the mechanical characteristics of poly-mer concrete using R-sand and M-sand

Numerous research studies have concentrated on advancing a sustainable construction industry through innovative concrete methods and materials. In this context, the present research specifically investigates polymer concrete, utilizing both River sand (R-sand) and Manufacturing sand (M-sand). The polymer content was incorporated into the concrete mix based on the weight of the cement, with varying percentages specifically 2%, 4%, 5%, 6%, and 8%. A slump cone test was conducted to assess the workability of the polymer concrete. Based on experimental studies, the optimal polymer percentage was determined to be 5%. This optimal dosage of polymer content significantly improved the mechanical properties of the polymer concrete. The Compressive Strength (CS), Split Tensile Strength (STS), Flexural Strength (FS), and Modulus of Elasticity (ME) were evaluated at both 7 and 28 days. When using R-sand, the mechanical properties of CS, STS, and FS increased by 13.65%, 12.20%, and 11.42%, respectively. Conversely, employing M-sand led to even greater improvements in strength properties: 19.18% for CS, 12.54% for STS, and 11.67% for FS. Based on the experimental results, the strength properties of polymer concrete M-sand mixes outperformed the R-sand mixes. Linear regression analysis and various codes were employed to predict the strength properties of CS, STS, FS and ME. The regression analysis and various codes successfully forecasted the strength properties of polymer concrete, with the predicted results closely correlated with the experimental results. Based on experimental investigations, the determined mix proportions are recommended for practical applications in various environmental conditions.Numerous research studies have concentrated on advancing a sustainable construction industry through innovative concrete methods and materials. In this context, the present research specifically investigates polymer concrete, utilizing both River sand (R-sand) and Manufacturing sand (M-sand). The polymer content was incorporated into the concrete mix based on the weight of the cement, with varying percentages specifically 2%, 4%, 5%, 6%, and 8%. A slump cone test was conducted to assess the workability of the polymer concrete. Based on experimental studies, the optimal polymer percentage was determined to be 5%. This optimal dosage of polymer content significantly improved the mechanical properties of the polymer concrete. The Compressive Strength (CS), Split Tensile Strength (STS), Flexural Strength (FS), and Modulus of Elasticity (ME) were evaluated at both 7 and 28 days. When using R-sand, the mechanical properties of CS, STS, and FS increased by 13.65%, 12.20%, and 11.42%, respectively. Conversely, employing M-sand led to even greater improvements in strength properties: 19.18% for CS, 12.54% for STS, and 11.67% for FS. Based on the experimental results, the strength properties of polymer concrete M-sand mixes outperformed the R-sand mixes. Linear regression analysis and various codes were employed to predict the strength properties of CS, STS, FS and ME. The regression analysis and various codes successfully forecasted the strength properties of polymer concrete, with the predicted results closely correlated with the experimental results. Based on experimental investigations, the determined mix proportions are recommended for practical applications in various environmental conditions.

Influence of fly ash on rheological behaviour of HVFA concrete

High-volume fly Ash (HVFA) concrete has gained significant attention recently due to its potential for reducing environmental impact and improving long-term durability. This project investigates HVFA’s influence on concrete rheology, aiming to explore its applicability in sustainable construction. HVFA concrete mixes M1 (30% fly ash), M2 (40% fly ash), and M3 (50% fly ash) were prepared, varying fly ash percentages as a partial cement replacement. Fresh concrete tests, including slump cone and flow table tests, assessed workability and flow characteristics. Hardened samples underwent compressive and split tensile strength tests to evaluate mechanical properties. Results provided insights into HVFA concrete rheology, focusing on workability, flowability, and mechanical performance. Additionally, the study explores potential environmental benefits and challenges linked to HVFA concrete. These findings aid in advancing sustainable concrete technologies, offering crucial insights for engineers, architects, and policymakers seeking innovative, eco-friendly construction materials and practices while addressing environmental challenges related to HVFA concrete.

Sustainable Utilization of Marble Dust and Rice Husk Ash as a Partial Substitute for Fine Aggregate in Concrete

A sustainable method for partially substituting fine aggregate in concrete with marble dust and rice husk ash is described. This approach focuses on the utilization of these materials to minimize environmental impact while maintaining the integrity of the concrete structure. In this study, the fine aggregate was partially substituted with marble dust and rice husk ash. Additionally, sisal fiber was incorporated as secondary reinforcement for concrete at percentages of cement by weight. Concrete has good compressive strength but is weak in tension and bending. Thus, sisal fibers were added to enhance the mechanical properties. Sisal fibers were included at 0.1% and 0.2% of cement weight for varying percentages of mineral admixture substitution. 30% of cement was replaced with mineral admixtures, with replacement levels of 0%, 10%, 15%, 20%, and 30% of marble dust and rice husk ash. The slump cone and compaction factor tests were performed on fresh concrete mixes to determine workability. Standard cubes, cylinders, and prisms were cast to evaluate the compressive, split tensile, and flexural strengths of the hardened concrete. The results show that the replacement of cement with marble dust and rice husk ash with sisal fiber as an additional reinforcing material shows considerable improvement in tensile and flexural strength. The material properties and test results are presented graphically.

Recycling of marble and granite waste in concrete by incorporating nano alumina

This study aims to evaluate the effect of using single and combined marble dust (MD), granite dust (GD) and nano alumina (NA) on the performance of Portland cement concrete. MD and GD were separately replaced by different percentages of cement (2, 4, 6, 8 and 10 wt%). Furthermore, NA was used as addition by different percentages (0.25, 0.5, 0.75, 1.0 and 1.25 wt%) in the individual mixtures. The optimal ratios for MD, GD and NA were used to design two concrete mixtures with combined 6%MD+ 1%NA and 6%GD+ 1%NA. The physical properties (consistency, initial and final setting times), the workability (slump cone test), the mechanical properties (compressive, splitting tensile and flexural strengths) and microstructure analysis (X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Energy-Dispersive X-ray (EDX)) were carried on the single and combined mixtures in addition to control mix. Results revealed a rise in the water quantity needed to achieve standard consistency, along with a reduction in both initial and final setting times, as the content of GD and NA increased. However, in comparison to the control mix, minor effects in the consistency or the setting times was observed when various MD contents were used. Regarding workability, its consistently decreased in all cases in correlation with the surface area of the materials utilized. The highest reduction was observed when employing NA, characterized by the largest surface area, followed by GD, and then MD, which had a marginal effect on workability. For hardened concrete, there was an improvement in strengths of samples with replacing individually MD and GD content up to 6% at all curing ages, followed by a decrease in strengths when the content reached 10% of cement replacement compared to control sample. Concrete mixtures with addition of NA showed significant improvement in strengths at all percentages of addition until reached the maximum increase in strength at 1% then slightly decreased. Concrete with combined (6%MD+1%NA) and (6%GD+1%NA) show significantly improved mechanical properties and compact microstructure enriched with C-S-H in comparison to concrete samples using 6%MD, 6%GD and 1%NA separately.

Optimization Studies of Iron Ore Tailings Powder and Natural Zeolite as Concrete Admixtures

The disposal of Iron ore tailings Powder (IP) is the primary concern for numerous steel industries. Similarly, natural zeolite, a significant by-product of volcanic eruptions, pollutes the environment to an extreme degree. This study investigates and implements the extensive use of IP and natural zeolite as admixtures in M20-grade concrete in order to address the challenges posed by IP and zeolite. By varying the admixture percentage, three distinct mix ratios were formed. First, sand was replaced by iron at concentrations of 5%, 10%, 15%, and 20%. Second, cement was replaced by zeolite at 5%, 10%, 15%, and 20%. In the final mixture, both sand and cement were substituted with iron ore powder and zeolite, respectively, at 5%, 10%, 15%, and 20%. Conplast SP 430, a water-reducing admixture, was used in all of the mixtures at 1% by weight of cement. The mechanical properties of concrete, including compressive strength, split tensile strength, and flexural strength, were studied. To evaluate the long-term properties of admixture-modified concrete, durability tests such as permeability tests, water absorption tests, rapid chloride attack tests, acid attack tests, and sulphate attack tests were conducted. In addition, slump cone tests and thermal conductivity tests were conducted on all the mix combinations to determine the changes in workability and thermal conductivity coefficient. The test results demonstrated that a mix containing 10% zeolite replaced with cement and 10% iron ore tailing powder replaced with sand has the highest performance in terms of strength and durability characteristics. The study also constructs a comparable cost estimate to ensure that its actual implementation is feasible. Doi: 10.28991/CEJ-2023-09-12-08 Full Text: PDF

A Study on the Substitution of Rice Husk Ash with Natural Sand of Cement Concrete

Researchers from all around the world are currently investigating the feasibility of utilizing agricultural and/or industrial wastes as a resource for the building sector. In addition to saving money, recycling these materials could aid in making the planet a cleaner, greener place to live. Fibrous waste products such as sugar cane bagasse and ethanol vapour are produced during the sugar refining process.. In this study, fine aggregate in concrete was replaced with rice husk ash at the volumetric percentages of 0%, 10%, 20%, 30%, and 40%. Testing was done on both fresh concrete, using methods like the slump cone test, and on hardened concrete, using methods like the compressive strength, split tensile strength, and flexural test. The slump value of the samples was found to decrease when the rice husk ash level enhanced. Up to 20% substitution of rice husk ash with fine aggregates resulted in an improvement in mechanical characteristics.

EFFECT ON PROPERTIES OF CONCRETE BY PARTIAL REPLACEMENT OF CEMENT WITH METAKAOLIN AND SUPERPLASTICIZER

Metakaolin, a pozzolanic material, has been recognized for its potential to enhance concrete properties, while superplasticizers are commonly used to improve workability and reduce water content in concrete mixtures. The experimental program involves the preparation of concrete mixtures with metakaolin replacements at different levels (by 0%, 5%, 10%, 15%, and 20% by weight of cement). A commercially available superplasticizer is added to the mixtures (by 0%, 0.5%, 1%, 1.5%, and 2% by weight of cement) to optimize workability. The properties of the resulting concrete, including slump cone test, compressive strength, flexural strength, split tensile strength are assessed. The results show that the incorporation of metakaolin in concrete leads to improved mechanical properties, with significant enhancements observed in compressive and flexural strengths. Moreover, the inclusion of a superplasticizer improves the workability of the concrete mixtures containing metakaolin, ensuring easier placement and compaction. Key Words: Concrete, Metakaolin, Superplasticizers.

Characteristics study of concrete strength using periwinkle seashell as cement partial replacement

Due to global population growth and improving economic conditions, infrastructure development in the form of residential homes and commercial structures is increasing yearly. The rising real estate market draws middle-class buyers to upscale apartments and opulent homes at steep discounts. On the other hand the availability of traditional construction materials are reducing. As a result, the idea of partial replacement is a good substitute. The current effort attempts to substitute periwinkle shells gathered from Chennai, the coastal metropolis, for traditional coarse aggregate. Through the compaction factor, slump cone, and flow tests in the fresh condition and the 14-day and 28-day compression tests, flexure tests, and split tension tests in the hardened state, an effort is made to assess the workability and strength of the partially replaced concrete in the laboratory. In addition to the aforementioned, tests are done on the periwinkle shell's influence value, breaking down value, specific gravity, absorption of water, and particle size distribution in order to evaluate the properties with those of conventional coarse aggregate in order to confirm the effectiveness of the former. A notional percentage is deduced through comparison analysis after partial replacement of periwinkle shells with gravel in various percentages of 0%, 20%, 30%, and 40% is carried out. This study reveals an understanding of the characteristics of building materials mixed with periwinkle shells and helps todetermine the ideal combined mixture percentage which can be recommended as an appropriate replacement construction material in the construction of elegant villas and luxury apartments.