Characteristics Of High Strength Concrete Research Articles

Influence of substituting aggregates on the characteristics of high-strength concrete

High-strength concrete (HSC) is a specialized form of concrete that possesses enhanced compressive strength compared to conventional concretes. In the initial phase of the experimental study, silica fume and metakaolin were utilized as additional supplementary cementitious materials in various percentages ranging from 6% to 12% for making different trails to obtain the concrete mix with high strength. Test results indicated that trail mix having 10% silica fume and metakaolin gave the desired strength. The second phase of the study incorporates the utilization of crushed granite coarse aggregates at varying replacement ratio ranging from 0 to 100%, serving as a substitute for natural aggregates. Test results demonstrated the better quality of crushed granite aggregates in contrast with locally available natural aggregates, enhanced strength properties of concrete including compressive strength, split tensile strength, Flexural strength, etc at each replacement percentage, thus suggesting the use of crushed granite a favorable option for obtaining high strength concrete.

Synergistic effect of recycling waste coconut shell ash, metakaolin, and calcined clay as supplementary cementitious material on hardened properties and embodied carbon of high strength concrete

Researchers are investigating eco-friendly binders like coconut shell ash (CSA), metakaolin (MK), and calcined clay (CC) as supplementary cementitious materials (SCM) in high-strength concrete (HSC). Abundantly available as industrial or agricultural waste, these materials, when combined with Portland cement (PC), offer synergistic benefits. This not only improves concrete performance but also addresses waste disposal issues, presenting a sustainable and environmentally friendly solution for long-term use in HSC production. However, this study performed on fresh and mechanical characteristics of HSC blended with CSA, MK, and CCA alone and together as SCM after 28 days of curing. A total of 504 samples of standard concrete were cast and the cubical samples were tested to achieve the targeted compressive strength about 80 MPa after 28 days. The experimental results indicated that the rise in tensile, flexural and compressive strengths of 9.62%, 8.27%, and 10.71% at 9% of CSA, MK, and CC as SCM after 28 days of curing. As SCM content increases, the density, porosity and water absorption of concrete decrease. Moreover, the workability of fresh concrete is getting reduced when the concentration of SCMs increases in HSC. In addition, the concrete's sustainability assessment revealed that employing 18% MK, CC, and CSA as SCM reduced carbon emissions by approximately 11.78%. It is suggested that using 9% CC, MK and CSA together in HSC yields the best results for practical applications in civil engineering.

Assessing the effect of natural fiber on mechanical properties and microstructural characteristics of high strength concrete

In light of environmental concerns such as global warming, there has been a dramatic rise in natural fiber concrete (NFC) research and development. The advantages of these materials over others, such as low environmental impact and minimal cost, warrant interest and support their potential across various applications. This study investigates mechanical properties and micro-structural analysis for M70 grade of high-strength concrete (HSC) under the effect of natural fiber with alccofine. Cement was partially replaced in this investigation by 15 % alccofine content. In this experiment, natural banana fiber (BF) and coir fiber (CF) were selected and added in concrete at 0.5 %, 1 %, 1.5 %, and 2 % by volume. Nine concrete mix compounds were developed and investigated the mechanical characteristics, including uniaxial compressive strength, splitting tensile strength, flexural strength, impact strength, and bond strength of concrete, and microstructural analysis, including scanning electron microscope (SEM), energy dispersive Xray spectroscopy (EDS), Fourier transform infrared (FTIR), and X-ray diffraction (XRD), were examined. The outcome of the results revealed that the inclusion of BF and CF with alccofine improves the mechanical characteristics of concrete compared to the control mix. Compared with reference HSC, 1 % banana fiber increased the mechanical performance after 28 days of curing. BF significantly enhanced the mechanical properties of high-strength concrete compared to CF. Furthermore, banana fiber provides early warning of failure due to its elasticity.

Influence of Natural Fiber Derived from Agricultural Waste on Durability and Micro-Morphological Analysis of High-Strength Concrete

This research focuses on the investigation of durability behavior and microstructural analysis for M70 grade of high-strength concrete (HSC) with the influence of alccofine, banana fiber (BF), and coir fiber (CF). In this investigation, cement was partly supplanted by 15% of alccofine content in weight. Two types of natural fibers, banana and coir fibers, were selected and added in concrete at 0.5%, 1%, 1.5%, and 2% by volume. Durability characteristics, such as long-term compressive performance, rapid chloride penetration, sorptivity, water absorption, volume of permeable voids, and acid attack resistance are investigated elaborately and correlate with conventional HSC. Results showed that the incorporation of banana and coir fibers with alccofine in HSC exhibited good durability performance as correlated with conventional HSC. At 180 days of curing, incorporating 1% of banana fiber increased the durability performance compared to reference HSC. Nonetheless, the high-fiber percentage of HSC has a slight reduction in durability characteristics. Among the two types of fibers, the banana fiber showed the most significant improvement in the durability properties of HSC. The influence of natural fiber on the microstructural characteristics of HSC was evaluated using scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) to substantiate the experimental findings. In contrast, using additional supplementary cementitious materials (SCMs) in HSC fabrication significantly reduces cement usage and carbon emissions.

Effect of calcined clay and marble dust powder as cementitious material on the mechanical properties and embodied carbon of high strength concrete by using RSM-based modelling

In the last decade, there has been an increase in research on ecologically benign, cost-effective, and socially useful cement alternative materials for concrete. Alternatives involve industrial and agriculture waste, the potential advantages of which may be recognized by recycling, repurposing, and recreating techniques. Important energy reserves and a decrease in Portland cement (PC) consumption may be attained by using these wastes as supplementary and substitute ingredients, contributing to a reduction in carbon dioxide (CO2) production. Consequently, the incorporation of marble dust powder (MDP) and calcined clay (CC) as supplementary cementitious material (SCM) in high strength concrete may lower the environmental effect and reduce the amount of PC in mixes. This study is conducted on concrete containing 0%, 5%, 10%, 15%, and 20% of MDP and CC as cementitious materials alone and in combination. The main objectives of this investigations are to examine the effect of MDP and CC as cementitious materials on the flowability and mechanical characteristics of high strength concrete. In order to examine the ecological effect of CC and MDP, the eco-strength efficiency and embodied carbon were considered. In this context, there are so many trial mixes were performed on cubical specimens for achieving targeted compressive strength about 60 MPa after 28 days. After getting it, a total of 273 concrete specimens (cubes, cylinders, and prisms) were used to test the compressive, splitting tensile, and flexural strength of high strength concrete correspondingly. Moreover, when the amount of MDP and CC as SCM in the mixture grows, the workability of green concrete decreases. In addition, the compressive strength, flexural strength, and splitting tensile strength are increased by 6.38 MPa, 67.66 MPa, and 4.88 MPa, respectively, at 10% SCM (5% MDP and 5% CC) over a period of 28 days. In addition, using ANOVA, response prediction models were generated and confirmed at a 95% level of significance. The R2 values of the models varied from 96 to 99%. Furthermore, increasing the amount of CC and MDP as SCM in concrete also reduces the amount of carbon embedded in the material. It is recommended that the utilization of 10% SCM (5% MDP and 5% CC) in high strength concrete is providing optimum outcomes for construction industry in the field of Civil Engineering.

Performance Assessment of High Strength Concretes Containing Foundry Sand as Fine Aggregate

Deposition of used foundry sand in landfills causing environmental hazard has been generating focus to develop alternate methods of disposal or applications. Research works in the recent period have been concentrated towards utilization of foundry sand in construction industry. Results with regard to the use of foundry sand in manufacturing construction materials like bricks and concrete have been quite promising and have provided a lot of scope for production of green materials. The present research work aims to study the mechanical and durability characteristics of high strength concrete containing foundry sand as a partial replacement of river sand. River sand was replaced with 20%, 40%, 60%, 80% and 100% foundry sand. Properties like slump, compressive strength, ultrasonic pulse velocity, water absorption, RCPT values were evaluated to report the performance characteristics. The results indicate that it is possible to achieve strengths greater than 50MPa upto 60% replacement of fine aggregate and nominal strengths at higher replacement percentages. Durability studies indicate that concretes containing foundry sand had inferior properties, however, all the values reported were well below the allowable limits.

OPTIMALISASI PENGGUNAAN PASIR BESI SEBAGAI PENGGANTI AGREGAT HALUS DALAM CAMPURAN BETON MUTU TINGGI

Infrastructure progress needs to be supported by the development of research on construction material technology, one of which is concrete technology. With its various advantages, concrete is continuously used to solve infrastructure problems. However, it also has impact on the use of large-scale materials and has the potential to deplete natural resources if not handled properly. One material that can be used as an alternative is iron sand. Iron sand is a mineral resource with magnesium content and has characteristics as a substitute for fine aggregate in concrete mixes. This study aimed to determine the effect of iron sand as a substitute for fine aggregate in high-strength concrete mixtures. This research method was a laboratory experiment by testing the characteristics of high strength concrete, namely compressive strength, tensile strength, and modulus of elasticity. This study found that the optimum concrete compressive strength occurred in the V-02 sample with a result of 51.71 MPa from the design compressive strength (fcr) = 45 MPa. The optimum tensile strength test occurred in the V-02 sample with a result of 4.13 MPa, and the optimum elasticity modulus test occurred in the V-02 sample producing 28684.37 MPa

Influence of Nano-Materials on Mechanical and Permeation Characteristics of High Strength Concrete

Influence of Nano-Materials on Mechanical and Permeation Characteristics of High Strength Concrete

Effect of Fiber Type on High Strength Concrete Mechanical Properties

One of the most important characteristics of concrete is its resistance to tensile and bending. In order to improve these two characteristics, some fibers can be used to form fiber-reinforced concrete. There are many fibers, which may be synthetic or natural, that can be used and their properties can be applied in the formation of concrete that resists many external and internal forces, including polyester, glass, polypropylene, and steel fiber. The incorporation of steel (SF) and polypropylene fiber (PF) and the examination and the comparison of engineering characteristics of high strength concrete (HSC) are the principal objectives of this examination. The general method used in this research is by adopting one high strength concrete mix. However, the work and concrete mixes are divided into 3 groups. The first group includes 0% steel fiber with polypropylene fiber in proportions (0, 0.1 0.2, 0.3, 0.4 and 0.5%). The second groups includes 0.5% steel fiber with polypropylene fiber (0, 0.1 0.2, 0.3, 0.4 and 0.5%) and finally the third group includes 1.0% steel fiber with polypropylene fiber (0, 0.1 0.2, 0.3, 0.4 and 0.5%). Compared to the mixture of regular concrete, the improvement in tensile, compressive flexural strength is the main advantage of the mixture, which has been observed after adding the used percentage of used fibers, which has been deduced from this research as the placement of fibers in the mixture intensified the strength features of mixtures. The maximum compressive strength, flexural tensile strength has been recorded for P0.2+S1.0 with polypropylene increasing percentage of 15.30, 15.32 and 15.317% and steel increasing percentage of 34.03, 36.51 and 36.41% respectively.

Influence of industrial wastes on the mechanical and durability characteristics of high strength concrete

In this paper, the possibility of using granite powder and bottom ash in high strength concrete mix is evaluated. Phase composition and microstructure of the aggregate are reported using X-ray diffraction and scanning electron microscopy, respectively. The laboratory investigation focuses on addressing the impact of different combinations of wastes (0% to 40%) on fresh and hardened state behaviour of high strength concrete at different ages and exposure conditions. Even though the inclusion of these wastes individually in concrete showed detrimental effects on strength properties, the waste in combination did not show significant influence on mechanical and durability parameters.

Prediction of Shear Strength of Reinforced High-Strength Concrete Beams Using Compatibility-Aided Truss Model

This study proposes an analytical model applicable to the shear analysis of reinforced high-strength concrete beams. The proposed model satisfies the equilibrium and compatibility conditions and constitutive laws of the materials. The proposed model is based on the fixed angle theory and allows the principal stress to rotate as the load increases, so that the RC beams can be analyzed more realistically. High-strength material models were used in the proposed model to consider the characteristics of high-strength concrete. The concrete shear contribution at crack surfaces was calculated from Mohr’s circle. The proposed model considers the effect of bending moment on shear by reducing the amount of longitudinal reinforcement resisting shear. To verify the accuracy of the proposed model, a total of 64 experimental results were collected from the literature. A comparison with previous experimental results confirmed that the proposed model can be predicted relatively accurately with an average of 0.98 and a coefficient of variation of 12.1%.

Mechanical and Microstructure Characterization of Alccofine Based High Strength Concrete

This study presents the influence of alccofine-1203 (alccofine) on mechanical and microstructure characteristics of High Strength Concrete (HSC). A total of 7 binder proportions were developed to evaluate the Standard Consistency (SC), Initial Setting Time (IST) and Final Setting Time (FST) of the binders, and mechanical properties of HSC. Scanning electron microscopic (SEM), energy dispersive X-ray spectroscopy analysis (EDS), X-ray diffraction (XRD) were used to study the microstructure characteristics of binder pastes. 4–14% of alccofine is used to replace cement form control mix. The test results showed that compared to control mix binder, the increase in alccofine replacement levels increased the SC slightly, but decreased the IST and FST. As alccofine replacement levels increased from 4 to 10%, the compressive and tensile strengths of concrete increased but 12 and 14% replacement levels reduced the strength of the concrete. Compared to the control mix, all the alccofine based mixes exhibited higher compressive and tensile strengths. SEM and EDS analysis demonstrated that compared to all other mix binders, mix with 10% alccofine had higher amount of C-S-H gel formation, stronger dense matrix with fewer pores and microcracks as well as low Ca/Si ratio. XRD analysis showed that mix with 10% alccofine revealed higher quantification of Alites and Larnites leading to higher early as well as later strengths to the M-10%AF mix compared to other mixes.

Effect of Varying Steel Fiber Content on Strength and Permeability Characteristics of High Strength Concrete with Micro Silica.

For the efficient and durable design of concrete, the role of fiber-reinforcements with mineral admixtures needs to be properly investigated considering various factors such as contents of fibers and potential supplementary cementitious material. Interactive effects of fibers and mineral admixtures are also needed to be appropriately studied. In this paper, properties of concrete were investigated with individual and combined incorporation of steel fiber (SF) and micro-silica (MS). SF was used at six different levels i.e., low fiber volume (0.05% and 0.1%), medium fiber volume (0.25% and 0.5%) and high fiber volume (1% and 2%). Each volume fraction of SF was investigated with 0%, 5% and 10% MS as by volume of binder. All concrete mixtures were assessed based on the results of important mechanical and permeability tests. The results revealed that varying fiber dosage showed mixed effects on the compressive (compressive strength and elastic modulus) and permeability (water absorption and chloride ion penetration) properties of concrete. Generally, low to medium volume fractions of fibers were useful in advancing the compressive strength and elastic modulus of concrete, whereas high fiber fractions showed detrimental effects on compressive strength and permeability resistance. The addition of MS with SF is not only beneficial to boost the strength properties, but it also improves the interaction between fibers and binder matrix. MS minimizes the negative effects of high fiber doses on the properties of concrete.

Experimental and numerical investigation of high-strength concrete encased steel columns with rectangular-spiral stirrups

In the present study, seismic performance of High-strength Concrete Encased Steel columns with Rectangular - spiral Stirrups (HCESRS) is investigated. The composite specimen was tested under reverse cyclic loading and numerically simulated by the finite element method. Using ABAQUS software, numerical analysis of the specimen was performed, including hysteresis curve, skeleton curve, stress comparison and energy dissipation. Experimental results were compared with the numerical simulation to verify the accuracy of the numerical analysis. The influence of parameter changes such as shear span ratio, axial compression, steel content of I-shape and steel yield strength of HCESRS column were investigated. It was found that as the shear span ratio increases, the ultimate bearing capacity of the member decreases and the deformation capacity increases. Due to the brittle failure characteristics of high strength concrete, the limit value of axial compression ratio of HCESRS column was systematically studied, and effect of axial compression ratio on the ductility for HCESRS column has been investigated. This numerical analysis reliably evaluated and analyzed the seismic response of the HCESRS column.

Strength Characteristics of High Strength Concrete (HSC) with and without Coarse Aggregate

This paper aimed to investigate the mechanical characteristics of HSC of M60 concrete adding 25% of fly ash to cement and sand and percentage variations of silica fumes 0%,5% and 10% to cement with varying sizes of 10mm,6mm,2mm and powder of granite aggregate with w/c of 0.32. Specimens are tested for compressive strength using 10cm X 10cmX10cm cubes for 7,14,28 days flexural strength was determined by using 10cmX10cmX50cm beam specimens at 28 days and 15cm diameter and 30cm height cylinder specimens at 28 days using super plasticizers of conplast 430 as a water reducing agent. In this paper the experimental set up is made to study the mechanical properties of HSC with and without coarse aggregate with varying sizes as 10mm, 6mm, 2mm and powder. Similarly, the effect of silica fume on HSC by varying its percentages as 0%, 5% and 10% in the mix studied. For all mixes 25% extra fly ash has been added for cement and sand.

LIGHTER HIGH STRENGTH CONCRETE BEAM

High strength concrete (HSC) has been used extensively in civil construction projects worldwide because it reduces the cross section and the weight of long construction members. In recent years a marked increase in the use of High Strength Concrete (HSC) has been evident in Australian building construction despite the fact that the current Australian design standard provides no design rules for such a material. Very limited information on the properties of HSC and its design and construction processes are available in Australia, although in recent times many studies have been undertaken to produce material and, more importantly, to determine its characteristic. In the last 20 years there has been extensive research to economically utilize new components to improve the quality of HSC. HSC produces smaller but stronger structural elements with large spaces available. It has been studied that the cost of using HSC instead of Normal Strength Concerete (NSC) in different types of constructions. This proved that structures constructed with HSC are lighter and economical compared with those constructed with NSC. In the long term durability significantly affects project costs. In other words after several years a concrete structure needs rehabilitation or in critical cases must be demolished, therefore the price of a project consists of initial costs plus those covering any rehabilitation. A huge amount of money could be saved by utilizing the durability characteristics of high strength concrete. This study presents recent information and the benefits of high strength concrete. Also, provides in brief an experimental proof that installing a helix with a suitable pitch and diameter in the compression zone of beams significantly enhances their strength and ductility. Therefore, designers could confidently use high-strength concrete and helical confinement to design long and light reinforced concrete beams.

Impact of twisting high-performance polyethylene fibre bundle reinforcements on the mechanical characteristics of high-strength concrete

The quasi-static and dynamic mechanical behaviours of the concrete reinforced by twisting ultra-high molecular weight polyethylene (UHMWPE) fibre bundles with different volume fractions have been investigated. It was indicated that the improved mixing methodology and fibre geometry guaranteed the uniform distribution of fibres in concrete matrix. The UHMWPE fibres significantly enhanced the splitting tensile strength and residual compressive strength of concrete. The discussions on the key property parameters showed that the UHMWPE fibre reinforced concrete behaved tougher than the plain concrete. Owing to the more uniform distribution of fibres and higher bonding strength at fibre/matrix interface, the UHMWPE fibre with improved geometry enhanced the quasi-static splitting tensile strength and compressive strength of concrete more significantly than the other fibres. The dynamic compression tests demonstrated that the UHMWPE fibre reinforced concrete had considerable strain rate dependency. The bonding between fibres and concrete matrix contributed to the strength enhancement under low strain-rate compression.

Strength Characteristics of High Strength Concrete using Recycled Aggregate and GGBS, Fly Ash

Strength Characteristics of High Strength Concrete using Recycled Aggregate and GGBS, Fly Ash

Review study on the current development of confined high-strength concrete

This paper reviews the current development of the confined high-strength concrete (HSC). The differences between conventional concrete and HSC, the detailed mechanical characteristics of HSC, advantages and disadvantages, and the importance of confinement in HSC are critically reviewed. The beneficial effects of confinement in improving the low-ductility of HSC are also discussed. In addition, the recent progress in the research on confined HSC is presented. Subsequently, the existing stress-strain models for confined concrete are reviewed. In conclusion, the review paper notes and highlights some essentials points from the aforementioned discussion where several recommendations have been made for the advancement of this ever-developing topic.

An Experimental Investigation on the Effect of Addition of Ternary Blend on the Mix Design Characteristics of High Strength Concrete using Steel Fibre

This paper presents the results of M60 grade of concrete. M60 grade of concrete is achieved by maximum density technique. Concrete is brittle and weak in tension and develops cracks during curing and due to thermal expansion / contraction over a period ot time. Thus the effect of addition of 1% steel fibre is studied. For ages, concrete has been one of the widely used materials for construction. When cement is manufactured, every one ton of cement produces around one ton of carbon dioxide leading to global warming and also as natural resources are finishing, so use of supplementary cementitious material like alccofine and flyash is used as partial replacement of cement is considered. The effect of binary and ternary blend on the strength characteristics is studied. The results indicate that the concrete made with alccofine and flyash generally show excellent fresh and hardened properties. The ternary system that is Portland cement-fly ash-Alccofine concrete was found to increase the strength of concrete when compared to concrete made with Portland cement or even from Portland cement and fly ash.