FORMULATION OF LIGHTWEIGHT CONCRETE

Abstract

The present invention relates to the development of a lightweight concrete composition that incorporates high-density polyethylene (HDPE) granules as a lightweight aggregate. By mixing HDPE with traditional concrete components—cement, sand, water, and additives—this method produces concrete with reduced density while maintaining strong mechanical properties. The resulting lightweight concrete offers benefits such as High Strength-to-Weight Ratio, improved thermal insulation, and enhanced resistance to moisture and chemicals, making it a sustainable and durable solution for construction practices.

Specification

Description:FORMULATION OF LIGHTWEIGHT CONCRETE
FIELD OF THE INVENTION
The present invention relates to the field of construction materials, specifically the development of lightweight concrete.

BACKGROUND OF THE INVENTION
The patented invention WO2017201607A1 provides a lightweight concrete formulation that incorporates Portland cement, aggregate, glass particles, water, and metakaolin, with the goal of achieving a reduced density while maintaining sufficient mechanical strength and durability. By utilizing expanded glass particles in specific grain sizes, the invention seeks to enhance the performance characteristics of the concrete, including its insulation properties and resistance to environmental factors.

The patented lightweight concrete formulation containing Portland cement, glass particles, and metakaolin has several limitations. Firstly, the reliance on glass particles, even in expanded form, can lead to challenges in achieving a uniform distribution within the concrete mix, potentially resulting in inconsistencies in mechanical properties. Furthermore, while glass can contribute to reduced density, it may not provide sufficient strength compared to other lightweight aggregates. The formulation's dependence on specific grain sizes also restricts its versatility, limiting the range of applications in which it can be effectively utilized. Additionally, the use of Portland cement in significant quantities contributes to the carbon footprint of the concrete, posing sustainability concerns.

The present invention addresses these limitations effectively. HDPE granules, being lighter and exhibiting a high strength-to-weight ratio, allow for a substantial reduction in concrete density without compromising mechanical strength. The compatibility of HDPE with traditional concrete ingredients facilitates a more uniform mix, resulting in consistent performance characteristics. Moreover, the use of recycled HDPE promotes sustainability and minimizing the environmental impact associated with concrete production. The enhanced thermal insulation and moisture resistance properties of HDPE also contribute to the longevity and durability of concrete structures.

OBJECT OF THE INVENTION
An object of the present invention is to provide a novel lightweight concrete formulation that effectively incorporates High-Density Polyethylene (HDPE) granules as an aggregate, thereby reducing the overall density of the concrete while maintaining or enhancing its mechanical strength and durability.
SUMMARY OF THE INVENTION
The present invention provides a novel method for producing lightweight concrete by incorporating High-Density Polyethylene (HDPE) granules as a lightweight aggregate. This innovative approach involves selecting HDPE granules for their low density and compatibility with traditional concrete ingredients, including cement, sand, water, and additives. The process entails thorough mixing of these components to achieve a uniform distribution, followed by casting the mixture into molds and implementing proper curing procedures to enhance the concrete's strength and durability.
The resulting lightweight concrete exhibits a significantly reduced density while maintaining satisfactory mechanical properties, such as compressive and tensile strength. Key advantages of using HDPE granules include a high strength-to-weight ratio, improved thermal insulation, and enhanced resistance to chemicals and moisture, which collectively contribute to the longevity and performance of concrete structures.
This invention not only addresses the need for lighter construction materials but also promotes sustainability by utilizing recycled HDPE, making it a valuable advancement in the field of construction materials. The comprehensive testing and evaluation of the concrete specimens demonstrate the effectiveness of HDPE granules in achieving a high-performance lightweight concrete solution suitable for various applications in the construction industry.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
The invention presents a comprehensive method for producing lightweight concrete by integrating high-density polyethylene (HDPE) granules as a lightweight aggregate. This approach leverages the unique properties of HDPE to enhance the performance of concrete while also addressing environmental concerns through the use of recycled materials.
To begin, HDPE granules are carefully selected due to their low density (approximately 0.922 g/cm3) and compatibility with standard concrete components. These granules are sourced from post-consumer plastic waste, which not only contributes to reducing landfill waste but also provides a sustainable option for lightweight aggregates. The granules are processed to ensure uniform size typically between 2.3 mm and shape, facilitating consistent mixing with other concrete materials.
The preparation of the concrete mixture involves a systematic approach. HDPE granules are combined with traditional ingredients such as cement (955 grams per cubic centimeter by weight), fine aggregates like sand (1200 kg/m3 by weight), and water (0.5 water-cement ratio), along with necessary additives such as silica fume to enhance workability. The proportions of these components are predetermined based on the desired properties of the final product. During this phase, it is crucial to achieve a mixture that ensures the HDPE granules are evenly distributed throughout the concrete matrix.
Once the mixture is prepared, it is cast into molds or structural forms designed according to specific project requirements. Care is taken to properly settle the mixture during casting to ensure the structural integrity of the final product. Following casting, the concrete undergoes standard curing methods, such as Water curing, which are implemented to maintain adequate moisture levels and promote optimal strength development over time.
After the curing period, the lightweight concrete specimens are subjected to a series of rigorous tests to evaluate their mechanical properties. These tests include measuring compressive strength (typically targeting values of 36Mpa), flexural strength, as well as tensile strength tests that assess flexural properties. Additionally, the density of the concrete aiming for 0.922 g/cm3 is measured to confirm its lightweight characteristics, ensuring that the incorporation of HDPE granules has achieved the desired reduction in weight.
The results of these evaluations typically demonstrate that the use of HDPE granules not only reduces the density of the concrete but also maintains satisfactory performance characteristics, including adequate strength and durability. The lightweight concrete produced through this method exhibits a high strength-to-weight ratio, making it an attractive option for various construction applications.
The incorporation of HDPE granules imparts several key advantages to the concrete. Additionally, HDPE is known for its thermal insulation properties, which enhance the energy efficiency of buildings constructed with this concrete. Furthermore, HDPE exhibits excellent resistance to moisture and a range of chemicals, which significantly improves the durability and longevity of concrete structures.
The lightweight concrete granules exhibit the following properties when incorporated with HDPE granules:
Property 0% HDPE (Control) 10% HDPE 20% HDPE 30% HDPE 40% HDPE 50% HDPE
Density (kg/m³) 1,800 1,700 1,600 1,500 1,400 1,300
Compressive Strength (MPa) 25 23 20 18 15 12
Flexural Strength (MPa) 3.5 4 4.5 5 5.2 5.5
Thermal Conductivity (W/m·K) 0.75 0.7 0.65 0.6 0.55 0.5
Water Absorption (%) 12 10 8 7 6 5
Impact Resistance (J) 10 12 14 16 18 20
Weight Reduction (%) 0 5 10 15 20 25
Cost Increase (%) 0 3 6 9 12 15

In summary, this invention provides a detailed methodology for creating lightweight concrete utilizing HDPE granules. It not only improves the mechanical and thermal performance of concrete but also promotes sustainability by incorporating recycled materials. This innovative approach holds promise for advancing construction practices while addressing environmental challenges.
ADVANTAGES OF THE INVENTION
This invention aims to promote sustainability in construction by utilizing recycled materials, offering improved thermal insulation properties, and enhancing the chemical and moisture resistance of concrete structures. Ultimately, the invention seeks to deliver a high-performance, lightweight concrete solution that meets the evolving needs of the construction industry.
It utilizes High-Density Polyethylene (HDPE) granules as an aggregate. This innovative approach aims to enhance the performance characteristics of concrete, reduce its overall weight, and promote sustainability by incorporating recycled materials into building practices. The invention addresses the need for high-performance, environmentally friendly construction solutions by improving the mechanical properties and durability of concrete while minimizing its environmental footprint. , Claims:WE CLAIM:
1. A concrete composition, comprises:
HDPE granules in range of 10 to 50%;
cement 955 g/cm3 by weight;
fine aggregates in 1200 kg/m3 by weight;
water for curing to provide moisture to said concrete composition; and
additive to enhance workability to obtain lightweight concrete, wherein said concrete composition is capable of enhancing flexural strength.
2. The concrete composition as claimed in claim 1, wherein said HDPE granules have low density of 0.922 g/cm3 and compatibility with other concrete composition components.
3. The concrete composition as claimed in claim 1, wherein said HDPE granules are sourced from post-consumer plastic waste which helps in reducing landfill waste and provides a sustainable option for the lightweight concrete.
4. The concrete composition as claimed in claim 1, wherein said HDPE granules are prepared of uniform size, particularly of 2.3 mm and are evenly distributed throughout concrete matrix.
5. The concrete composition as claimed in claim 1, wherein said concrete composition is poured into molds of desired structural forms and allowed to settle for desired structural integrity to obtain the lightweight concrete.
6. The concrete composition as claimed in claim 1, wherein said curing maintains adequate moisture levels and promotes optimal strength development of the developed structural form.
7. The concrete composition as claimed in claim 1, wherein said additive is silica fume.
8. The concrete composition as claimed in claim 1, wherein said fine aggregates are sand.
9. The concrete composition as claimed in claim 1, wherein said water is used in 0.5 ratio with the cement.
10. The concrete composition as claimed in claim 1, wherein said lightweight concrete measures compressive and tensile strengths of 18 and 5 MPa, respectively, at 30% HDPE.

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