A novel concrete composition using metakaolin and polypropylene fiber

Abstract

The present invention relates to a novel composition of M25 grade cement partially substituted with metakaolin and polypropylene fiber. The method comprises partially replacing cement with 10% metakaolin, and incorporating polypropylene fibers at different percentage variations of polypropylene, i.e., 0%, 0.25%, 0.50%, 0.75%, and 1.00%, with a w / c ratio of 0.45 separately by weight. This results in concrete with enhanced compressive strength, flexural strength, and splitting tensile strength compared to conventional concrete, with reducing density. The invention allows for supplementary application of metakaolin waste from the ceramic industry, contributing to sustainable construction practices.

Description

Field of Invention:The present invention relates to the novel M25 grade concrete composition comprising metakaolin and polypropylene fiber and to the method of preparation thereof. The composition of the present invention increases the streangth, longitivity, and resistance to cracking of the concrete mix. The present invention provides the overall impact on the concrete mix with improved mechanical features and suitable for several applications. Additionally, the invention includes metakaolin obtained from industrial waste, are sustainable materials in the construction industry.Background of Invention: In India, cement demand increases daily due to more demand for concrete. In the financial year of 2023, the domestic production of cement stood at 35l million tons, and it will rise at an annual growth rate of 7-8%. Increased cement demand increases fuel use, energy inputs, lime excavation, resource waste, and atmospheric CO2 emissions. CO2 is a measure of polluting greenhouse gas responsible for Global warming. Utilization of Portland cement cannot be avoided until the unforescen future, and the partial replacement of Portland cement with supplementary cementitious materials (SCMs) becomes more significant for construction in the future. The construction industry is responsible for taking control cement consumption by finding new ways. i.e., Granulated Blast Furnace Slag (GBFS), Silica Fume (SF), Metakaolin (MK), Fly Ash (FA), and Rice Husk Ash (RHA) can reduce the cost of producing concrete and have positive effects on the environment. SCMs are by-products of industries like thermal power plants, steel manufacturing industries, ceramic industries, ferrosilicon alloys, silicon metal, copper manufacturing industries, etc. SCMs are byproducts; they do not require energy consumption and are sustainable materials in the construction industry. These SCMs impart strength and durability to concrete by acting as a flling agent. SCMs are pozzolanic materials with finely ground particles that enhance concrete mixtures' fresh and hardened qualities by replacing the OPC portion or whole. The concrete is superior in compresion but weak in tension. Concrete has less ductility, low tensile strength, high brittleness, and less impact toughness; due to these engineering properties, has many limitations. Randomly distributed fibers in concrete are one of the most effective methods to enhance tensile and compressive strength, energy absorption capacity. Another adverse effect is that there are cracks in concrete samples due to inadequate dimensional stability, but using fiber in concrete reduces cracks.An article entitled as “Combined effect of GGBS and metakaolin on mechanical properties of strength of concrete” by M. A. Saeed et. al., published in International Journal of Creative Research Thoughts (IJCRT), 10 (5) (2022), 97-108, discloses about partial replacement of cement with Metakaolin (MK) and Ground Granulated Blast Furnace Slag (GGBS) in a composition of M25 grade concrete, wherein 15% MK and 9% GGBS are replaced for cement. This article also discloses that the improvement in compressive strength, split tensile strength and flexural strength as up to 41.12 MPa, 4.16 MPa, and 5.15 MPa respectively, wherein 53-grade cement based on IS:8112-198 was used.The present invention focuses on producing a novel composition and a method of producing fiber incorporated concrete comprising metakaolin as partially replacement (10% by weight) with 43-grade cement (OPC) and applying different dosages (0.25%, 0.50%, 0.75% and 1%) of polypropylene fiber to achive enhanced mechanical streangth. The present invention also focuses on characterization of the new composition of M25 concrete on slump value, compressive strength, split tensile strength, flexural strength, and density to get the enhancement in mechanical properties.The present inventors felt that the mechncical properties of M25 grade cement could be improved by partially substituting the cement (OPC) with metakaolin and polypropylene fiber. This remains the objective of the present invention.Objects of the inventionAn object of the present invention is to provide a novel composition of M25 concrete with partial replacement of cement by fibres like metakaolin and polypropylene to enhance mechanical properties of M25 concrete..Another object of the present invention is to develop process for obtaining the composition. Another object of the present invention is to focus on production of low density of M25 concrete potentially leading to lighter structures.Further object of the present invention is to reduce environmental load by reducing cement content and utilizing industrial waste such as metakaolin.Summary of Invention: In line with the above, the present invention provides a novel composition of M25 grade cement partially substituted with metakaolin and polypropylene fiber wherein said composition comprises; i. M25 grade cement in an amount of 90%w / w;ii. Metakaolin in an amount of 10%w / w; iii. Polyproylene fiber 0 to 1%w / w. In another aspect, the present invention provides a method that involves replacing 10% of ordinary Portland cement with metakaolin, a calcined clay product derived from kaolin. In another aspect, the present invention provides a method of producing fiber incorporated concrete comprising metakaolin as partially replacement (10% by weight) with cement and applying different dosages (0.25%, 0.50%, 0.75% and 1%) of polypropylene fiber, thereby improving its mechanical strength. In an aspect, the present invention discloses a method for preparing the composition comprising:a. Designing the concrete mixture as per IS standad to achive M25 grade concrete;b. Adding metakaolin to step (a) to replace cement upto 10% by weight; c. Preparing five samples with percentage variations of polypropylene, i.e., 0%, 0.25%, 0.50%, 0.75%, and 1.00%, with a w / c ratio of 0.45 separately; d. Adding the prepared polypropylene mixture of step (c) of different dosages separately to the mixture prepared in step b and e. Mixing all the components to achieve homogeneous mixture.Brief Description of Drawings: Figure 1: Illustrates graphical representation on workability for metakaolin and polypropylene fiber;Figure 2: Illustrates graphical representation on compressive strength for metakaolin and polypropylene fiber;Figure 3: Illustrates graphical representation on flexural strength for metakaolin and polypropylene fiber;Figure 4: Illustrates graphical representation on splitting tensile strength for metakaolin and polypropylene fiber;Figure 5: Illustrates graphical representation on density for metakaolin and polypropylene fiber;Detailed Description of the Invention:The invention will now be described in detail in connection with certain preferred and optional embodiments, so that various aspects thereof may be more fully understood and appreciated. However, any skilled person will appreciate the extent to which such embodiments could be extrapolated in practice.Unless specified otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art, to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described.Unless stated to the contrary, any of the words “contains”, “containing”, "including," "includes," "comprising," and "comprises" mean "including without limitation" and shall not be construed to limit any general statement that it follows to the specific or similar items or matters immediately following it. Embodiments of the invention are not mutually exclusive, but may be implemented in various combinations. The described embodiments of the invention and the disclosed examples are given for the purpose of illustration rather than limitation of the invention.Further, words like “a”, “an”, “at least” and “the” should be construed to not only cover singular quantities but also plural quantities of the elements immediately following them.The present invention addresses several critical challenges in the construction industry, including the environmental impact of cement product, the requirement of improved concrete properties, and the sustainable application of supplementary cementitious materials (SCMs), byproducts of industries i.e. industrial waste materials.Accordingly, the the present invention relates to a novel composition of M25 grade cement partially substituted with metakaolin and polypropylene fiber wherein said composition comprises; i. M25 grade cement in an amount of 90% w / w;ii. Metakaolin in an amount of 10% w / w; andiii. Polyproylene fiber (PPF) 0 to 1% w / w.In another embodiment, the composition of the present invention comprises; i. 90% Ordinary Portland cement (OPC) of 43-grade cement +10% Metakaolin + 0.25% PPF; ii. 90% Ordinary Portland cement (OPC) of 43-grade cement +10% Metakaolin + 0.50% PPF; iii. 90% Ordinary Portland cement (OPC) of 43-grade cement +10% Metakaolin + 0.75% PPF;iv. 90% Ordinary Portland cement (OPC) of 43-grade cement +10% Metakaolin +1.0% PPF;In another embodiment, the composition of M25 grade concrete partially substituted with metakaolin and polypropylene fiber is characterized byi. Slump value in the range of 75-65 mm; ii. Flexural strength in the range of 4.0-4.5 MPa; iii. Compressive strength in the range of 34-37 MPa;iv. Tensile strength in the range of 3.5-4.0 MPa; v. Density in the range of 2180-2230 Kg / m3.In an embodiment, the Ordinary Portland cement (OPC) of 43-grade comprises as depicted in Table 1 below:TableIn another embodiemnt, the present invention relates to a method for producing new concrete composition using metakaolin and polypropylene fiber in place of cement, wherein 10% of cement is supplemented with metakaolin and polypropylene fiber.In an aspect, the present invention considers the following materials and composition:(a) Cement: Ordinary Portland Cement (OPC) was used as primary binder for concrete preparation; (b) Metakaolin: Metakaolin is a kind of pozzolanic materials with finely ground particles and it is produced by calcining kaolin clay. In this present invention, 10% by weight of the cement was replaced by metakaolin. Table 1 shows the chemical composition of the Metakaolin and cement used in this present invention;(c) Polypropylene Fibers: Polypropylene Fibers are synthetic fibre, used at varying amounts such as 0%, 0.25%, 0.50%, 0.75%, and 1.00%, with a w / c ratio of 0.45 separately;(d) Aggregates and Water: Standard amount of aggregates and water were used (ratio of w / c is 0.45);In an embodiment, the present invention discloses a method for preparing the composition comprising:a. Designing the concrete mixture as per IS standad to achive M25 grade concrete;b. Adding metakaolin to step (a) to replace cement upto 10% by weight; c. Preparing five samples with percentage variations of polypropylene, i.e. 0%, 0.25%, 0.50%, 0.75%, and 1.00%, with a w / c ratio of 0.45 separately; d. Adding the prepared polypropylene mixture of step (c) of different dosages separately to the mixture prepared in step b and e. Mixing all the components to achieve homogeneous mixture.In an embodiment, the present invention identified optimized value of cement to be replaced with metakaolin is 10% by weight of cement to achive enhanced mechanical streangth. In an embodiment, the present invention discloses the effect of MK and PPF on concrete's flexural, tensile, and compressive strength.Accordingly, concrete mix design was done as per IS 10262:2019 to obtain the characteristic compressive strength of 25 N / mm2. This grade (M25) was considered for performing the study of partial replacement of MK in concrete. The materials used in the study are as follows: a. Cement: 90% Ordinary Portland cement (OPC) of 43-grade cement having features such as specific gravity 3.15, surface area 3000 cm2 / gm, bulk density 1450 Kg / m3, and consistency of 33% as per IS 8112: 2013;b. Fine aggregates (FA): Fine aggregates (FA) such as river sand that passes from an IS sieve 4.75 mm, with features like specific gravity 2.65, and fineness modulus 2.727, and fine aggregate confirms to Zone–II gradation as per IS: 383-1970;c. Coarse aggregates (CA): Coarse aggregates (CA) of size to be used around 20 mm, having specific gravity 2.64, and maximum water absorpbable capacity upto 3.40%;d. Metakaolin (MK): 10% metakaolin (MK), industrial by-products, of particle surface area 700 m2 / Kg, and specific gravity 2.60;e. Polypropylene fiber (PPF): 0% to 1% polypropylene fiber (PPF), a synthetic fiber, made from polypropylene polymerization;f. Superplasticizer: 0.65% Superplasticizer (of the weight of the cement) having specific gravity at 30 °C ranged from 1.175 to 1.190; andg. Water.Methodology:(a) Using five samples with percentage variations of PPF, i.e., 0%, 0.25%, 0.50%, 0.75%, and 1.00%, with a w / c ratio of 0.45 in the composition of M25 grade concretae and 10%metakaolin. Preparing 36 compression test specimens with previously stated mixture; (b) Selecting 18 beams and 18 cylindrical specimens to conduct the test; (c) Determining 7 and 28-days compressive strength; and(d) Conducting another test for 28 days of concrete’s flexural and splitting tensile strength; and(e) Conducting the workability tests using slump mould in standard sizes as per IS: 7320 (1974).As per the study, it was observed that the presence of 10% metakaolin and polypropylene fiber in concrete mixture shows synergistic effect with enhanced mechanical properties. Table 1, Table 2, Table 3, and Table 4 combined shows the significant enhancement of compressive strength, flexural strength, and splitting tensile strength, and reduction of density with overall improvement of mechanical properties of the desired concrete. It was further observed that the presence of 0.50% of polypropylene results for maximum increase of 25% of flexural strength, the presence of 0.75% of polypropylene results for maximum increase of 36% splitting tensile strength, the presence of 1.00% of polypropylene results for minimum 6.75% lower density achieved that potentially leading to lighter structures.In another embodiment, the present invention provides the slump test, performed as a quality control test for metakaolin and polypropylene fiber from batch to batch. It shows acceptable workability even with fiber addition. Figure 1 and Table 2 shows significant enhancement effect in presence and absence of fibers in the concrete mixture. In another embodiment, the present invention provides the clear manifestation on compressive streangth (MPa) variation in presence and absence of metakaolin and polypropylene fiber from batch to batch. Table 3 and Figure 2 shows the enhancement on compressive streangth (MPa) tested on 6 specimens for 7 days and 28 days separately. As per experimental result, on 28th day better compressive streangth was observed for optimal range of (0% to 0.25%) of polypropylene, 10% of metakaolin, 90% of cement along with other standard composition of M25 concrete.In another embodiment, the present invention provides the Flexural Strength Beam samples test conducted for 28 days, performed as a quality control test conducted in presence and absence of metakaolin and polypropylene fiber from batch to batch. It shows enhancement on Flexural Strength (MPa) tested on 6 specimens for 28 days. Here, Figure 3 and Table 4 shows significant enhancement of Flexural Strength (MPa) in presence and absence of fibers in the concrete mixture. In a preferred embodiment, the composition of cement (90%), metakaolin (10%), and polypropylene (0.75 %) showed the enhanced Flexurial strength as compared to standard composition of M25 concrete.In yet another embodiment, the present invention provides the Splitting Tensile Strength Spherical samples test conducted for 28 days, performed as a quality control test conducted in presence and absence of metakaolin and polypropylene fiber from batch to batch. It shows enhancement on Splitting Tensile Strength (MPa) tested on 6 specimens for 28 days. Here, Figure 4 and Table 5 shows significant enhancement of Splitting Tensile Strength (MPa) in presence and absence of fibers in the concrete mixture. Here, best combination is depicted as cement (90%), metakaolin (10%), and polypropylene (0.75 %) along with other standard composition of M25 concrete.In yet another embodiment, density measured for different blend compositions as depicted in Figure 5 and Table 6, shows gradually reduced density (measured in Kg / m3) with the increament of polypropylene fibre, cement (90%), metakaolin (10%), along with other standard composition of M25 concrete. As per the experimental result it has been found that, the compressive streangth is increased by 33.11% and 15.41% at 7 and 28 days respectively with respect to the standard composition as control; the flexural strength is increased at least by 25% at 28 days with respect to the standard composition as control when the polypropylene fiber dosage used by 0.50 by weight; the splitting tensile strength is increased at least by 36% at 28 days with respect to the standard composition as control when the polypropylene fiber dosage used by 0.75 by weight; the dosage of 10% metakaolin, and 1% polypropylene fiber, the density is 6.75% less than the standard composition as control used in M25 concrete.In an embodiment, the novel composition of the present invention comprising of (cement (90%), metakaolin (10%)) and optimized proportions of polypropylene fibre along with other standard composition of M25 concrete composition enhances the strength properties that make this concrete suitable for high-performance structures such as high-rise buildings, bridges, and other demanding structural applications. Again, reducing the usage of cement and supplementing the cement with utilization of industrial by-products like metakaolin, and polypropylene align with green building practices and regulations; lower CO2 emissions due to reduced cement content ensuring reduction in environmental pollution and providing significant sustainable construction approach with cost-effective solution. The present invention improves concrete durability and life-span due to the incorporation of fibers able to enhance crack resistance, potentially reducing maintenance costs. In an embodiment, the present invention provides a method to improve the mechanical properties of the M25 grade concrete by replacing the cement with 10% metakaolin and PPF in suitable amounts. Advantages of present invention:1. Utilizing metakaolin waste in construction encourages the recycling and reuse of industrial by-products, contributing to sustainable practices and reducing the environmental impact of waste disposal.2. Reusing metakaolin as a construction material reduces the amount of industrial waste that would go to landfills for disposal. This helps to meet the primary goal of reducing the environmental effects of waste disposal.3. The potential of metakaolin to reduce carbon dioxide emissions from concrete is one of its main environmental advantages. Metakaolin is a by-product of the calcination of kaolin clay, and its use in concrete allows for the partial replacement of cement. Since metakaolin can partially replace cement, which is the primary source of carbon dioxide emissions during manufacturing, the overall carbon footprint can be reduced.4. Generally, less energy is required to produce metakaolin than cement. Metakaolin can be added as a supplemental material to reduce energy consumption and improve the environmental impact of the concrete production process.5. Using metakaolin in place of certain cement reduces the need for raw materials like limestone and clay that are typically used in cement manufacture. This minimizes the adverse effects of quarrying and extraction activities on the environment and helps preserve natural resources.6. Polypropylene fiber is a highly recyclable material. Its ease of recycling and reuse in producing new goods reduces waste and demand for raw materials.7. Compared to other synthetic fibres, polypropylene fibre manufacture typically uses less energy. Reducing the energy used in manufacturing lowers greenhouse gas emissions and the overall environmental effect. ExamplesThe following examples further illustrates the experiemental details with cement (90%), metakaolin (10%), and optimized proportions of polypropylene fibre along with other standard composition of M25 concrete composition. These examples are not intended to limit the invention in any manner.Example 1:The materials required to form novel M25 concrete are as follows:1. Cement: Ordinary Portland cement (OPC) of 43-grade cement locally available in the market is used in this investigation, adhering to various IS 8112: 2013 specifications. OPC's specific gravity was 3.15, surface area 3000 cm2 / gm, bulk density 1450 Kg / m3, and consistency was 33% as per IS 8112: 2013. Table 1 provides the information about OPC's chemical composition.2. Fine aggregates (FA): The river sand was used as fine aggregates and brought from Banas Tonk, Rajasthan, that passes from an IS sieve 4.75 mm and conforms to the requirement of IS: 383-1970. From testing, FA`s specific gravity and fineness modulus were observed 2.65 and 2.727 respectively. This fine aggregate confirms to Zone–II gradation as per IS: 383-1970.3. Coarse aggregates (CA): The coarse aggregates used in this study were utilized from nearby quarry units. The maximum size used in this investigation is 20 mm for CA. The specific gravity and the maximum water absorption were observed at 2.64 and 3.40%, respectively, from testing.4. Metakaolin (MK): Table 1 provides information about MK's chemical composition. The color of MK was observed to be off-white. The particle surface area and specific gravity were 700 m2 / Kg and 2.60, respectively. MK was prepared by calcinating kaolin at 800o C for 4 hours and MK's mineralogical and chemical composition. 5. Polypropylene fiber (PPF): Polypropylene (PPF) is a synthetic fiber. It is white in colour and made from polypropylene polymerization. It has several advantages, such as being lightweight, highly tough, and corrosion-resistant. According to the size, PPF is classified as micro and macro PPF. The non-absorbent PPF has a melting point of 165 °C, three distinct lengths of 6.0 mm, 12.0 mm, and 19.0 mm, and an equivalent diameter of 48 μm.6. Superplasticizer: The prime object of a superplasticizer is to create workability when producing water content of 30%. Enfiiq Super Plast 400 is the high-range water-reducing admixture used in these experiments. The specific gravity of the superplasticizer at 30 °C ranged from 1.175 to 1.190. The applied super-plasticizer dosage is 0.65% of the weight of the cement.7. Water: The drinking water was used for this study.The following methodology was followd for conducting experiments:Concrete mix design was done as per IS 10262:2019 to obtain the characteristic compressive strength of 25 N / mm2. This grade (M25) is considered for performing the study of partial replacement of MK in concrete. There are five samples with percentage variations of PPF, i.e., 0%, 0.25%, 0.50%, 0.75%, and 1.00%, with a w / c ratio of 0.45. There are 36 compression test specimens to determine 7 and 28-days compressive strength and 18 beams and 18 cylindrical specimens to test 28 days of concrete’s flexural and splitting tensile strength.1. Workability: To ensure consistency, the slump test was performed as a quality control test for PPF and MK from batch to batch. The homogeneity of the fiber distribution inside the concrete, their interaction with the cement matrix, and the ease with which the concrete can be sprayed or cast all impact the fiber quality. The workability tests were conducted using slump mould in standard sizes per IS: 7320 (1974). (Reference Table 2, and Figure 1).2. Compressive Strength: Compressive strength is one of the main characteristics of hard concrete and is frequently used as a distinctive property for concrete classification. 150 x 150 x 150 mm steel moulds were tested in a 2000-KN capacity compression testing machine after being permitted to cure for 7 and 28 days in a curing tank at standard temperature. The test procedures used per IS 516 (Part-1 Sec-I) - 2021. (Reference Table 3, and Figure 2).3. Flexural Strength: The steel moulds of 500 x 100 x 100 mm size were tested in a universal testing machine after being permitted to cure for 28 days in a curing tank at standard temperature. The test procedures used as per IS 516 (Part-1 Sec-I) 2021. (Reference Table 4, and Figure 3).4. Split Tensile Strength: Concrete`s split tensile strength agrees with concrete's flexural and compression performance. The specimen shall be a cylinder, 300 mm long and 150mm in diameter, and be well-tightened and oiled thoroughly. The moulds were tested from a universal testing machine after being permitted to cure for 28 days in a curing tank at standard temperature. The test procedure was used per IS 516 (Part-1 Sec-I) – 2021. (Reference Table 5, and Figure 4).TablesTable 1. Chemical composition of cement and metakaolin. Table 2. Workability for metakaolin, and polypropylene.Table 3. Compressive strength for metakaolin, and polypropylene.Table 4. Flexural strength for metakaolin, and polypropylene.Table 5. Splitting tensile strength for metakaolin, and polypropylene.Table 6: Density for metakaolin, and polypropylene.The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

Claims

1. A novel composition of M25 grade concrete partially substituted with metakaolin and polypropylene fibre wherein said composition comprises: i. M25 grade cement in an amount of 90% w / w; ii. Metakaolin in an amount of 10% w / w; and iii. Polyproylene fibre (PPF) 0 to 1% w / w.

2. The composition of M25 grade concrete as claimed in claim 1, wherein the composition further comprises: i) 90% Ordinary Portland cement (OPC) of 43-grade cement + 10% Metakaolin + 0.25% PPF; ii) 90% Ordinary Portland cement (OPC) of 43-grade cement + 10% Metakaolin + 0.50% PPF; iii) 90% Ordinary Portland cement (OPC) of 43-grade cement + 10% Metakaolin + 0.75% PPF; and iv) 90% Ordinary Portland cement (OPC) of 43-grade cement + 10% Metakaolin + 1.0% PPF.

3. The composition of M25 grade concrete as claimed in claim 2, wherein the composition is characterized by: i) Slump value in the range of 75-65 mm; ii) Flexural strength in the range of 4.0-4.5 MPa; iii) Compressive strength in the range of 34-37 MPa; iv) Tensile strength in the range of 3.5-4.0 MPa; and v) Density in the range of 2180-2230 Kg / m3.

4. The composition of M25 grade concrete as claimed in claim 1, wherein the Ordinary Portland cement (OPC) of 43-grade comprises: CaO, SiO2, Fe2O3, Al2O3, MgO, K2O, Na2O, and SO3 of 64.7, 21.6, 2.2, 6.1, 0.8, 0.6, 0.1, and 1.92 (in percent) for cement; and 51.3, 0.2, 1.5, 43.8, 0.3, 0.4, 0.1, and 0.05 (in percent) for MK respectively.

5. A method for preparing the M25 grade concrete partially substituted with metakaolin and polypropylene fibre comprising: a. Designing the concrete mixture as per IS standad to achive M25 grade concrete; b. Adding metakaolin to step (a) to replace cement upto 10% by weight; c. Preparing five samples with percentage variations of polypropylene, i.e. 0%, 0.25%, 0.50%, 0.75%, and 1.00%, with a w / c ratio of 0.45 separately; d. Adding the prepared polypropylene mixture of step (c) of different dosages separately to the mixture prepared in step b; and e. Mixing all the components to achieve homogeneous mixture.

6. The composition of M25 grade concrete as claimed in any one of the preceding claims, wherein the composition enhances the mechanical properties, reduces the density, reduces the crack formation. .

7. The composition of M25 grade concrete as claimed in any one of the preceding claims for use in high-performance structures such as high-rise buildings, bridges, and other demanding structural applications.

8. A method to improve the mechanical properties of the M25 grade concrete by replacing the cement with 10% metakaolin and PPF in suitable amounts as claimed in any one of the preceding claims .