METHOD FOR PREPARATION OF SUSTAINABLE TERNARY BLENDED CONCRETE USING SILICA FUME AND ZEOLITE

Abstract

METHOD FOR PREPARATION OF SUSTAINABLE TERNARY BLENDED CONCRETE USING SILICA FUME AND ZEOLITE The present invention provides a sustainable and effective method for preparing ternary blended concrete using silica fume and zeolite. This method optimizes the properties of concrete while reducing its environmental footprint, offering significant advantages in terms of performance, durability, and cost-effectiveness. The concrete exhibits improved resistance to chemical attack, reduced permeability, and enhanced mechanical properties compared to conventional concrete.

Specification

Description:4. DESCRIPTION

Technical Field of the invention

The present invention relates to a method for preparing a sustainable ternary blended concrete, particularly for construction applications, which incorporates silica fume and zeolite as supplementary cementitious materials (SCMs) to enhance the mechanical properties, durability, and environmental sustainability of concrete. This method improves the performance of traditional Portland cement-based concrete by reducing the carbon footprint and utilizing industrial by-products, thus contributing to eco-friendly building practices.

Background of the invention

Concrete is one of the most widely used construction materials in the world, but its production is responsible for significant environmental impact, primarily due to the high CO₂ emissions associated with the manufacture of Portland cement. Various efforts have been made to reduce the environmental footprint of concrete by using supplementary cementitious materials (SCMs), such as fly ash, slag, and silica fume.

Zeolite, a naturally occurring aluminosilicate mineral, has gained attention as an SCM due to its pozzolanic properties and its ability to enhance the performance of concrete. Silica fume, a by-product of silicon and ferrosilicon production, is well-known for its excellent ability to improve concrete's strength, durability, and resistance to chemical attacks.

However, there is a need for an efficient method to combine silica fume and zeolite in a ternary blend, optimizing their complementary properties to produce high-performance, sustainable concrete. The present invention addresses this need by providing a method for the preparation of ternary blended concrete using silica fume and zeolite, thus improving concrete's sustainability and mechanical performance.

Brief Summary of the invention

The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key/critical elements of the invention or delineate the scope of the invention. Its sole purpose is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later.

The present invention provides a novel method for preparing a sustainable ternary blended concrete using silica fume and zeolite as supplementary cementitious materials. The method includes the following steps:

1. Selection of Raw Materials:
i) Portland cement, silica fume, and zeolite are selected as the primary materials for the concrete mix.
ii) The silica fume and zeolite are sourced from environmentally friendly and sustainable production methods to ensure the sustainability of the concrete mix.

2. Preparation of the Zeolite and Silica Fume Blend:
i) The zeolite and silica fume are processed to the desired particle size (e.g., fine grinding) to ensure uniform dispersion and compatibility with the Portland cement matrix.
ii) The zeolite may be treated, such as through activation processes like acid or thermal treatment, to enhance its pozzolanic reactivity.
iii) The ratio of silica fume to zeolite in the ternary blend is optimized to balance strength development, workability, and durability. Typical ratios range from 5-20% silica fume and 5-15% zeolite by weight of cement, depending on the specific requirements of the application.

3. Blending Process:
i) The Portland cement, silica fume, and zeolite are mixed with water and other concrete ingredients (such as aggregates, superplasticizers, and other additives) to form a homogeneous concrete mix.
ii) The blending process ensures uniform distribution of silica fume and zeolite particles in the concrete matrix, promoting improved microstructure and enhanced properties.

4. Casting and Curing:
i) The mixed concrete is cast into molds and cured under controlled conditions (e.g., standard curing or accelerated curing) to ensure proper hydration and strength development.
ii) The curing process is optimized for the ternary blend to achieve maximum strength and durability, taking into consideration the slower hydration characteristics of the silica fume and zeolite components.

5. Testing and Performance Evaluation:
i) The prepared concrete mix undergoes standard testing for compressive strength, workability, setting time, and durability, including resistance to sulfate attack, chloride ingress, and shrinkage.
ii) The performance of the ternary blended concrete is compared with conventional Portland cement-based concrete and binary blended mixes (e.g., Portland cement + silica fume or Portland cement + zeolite) to evaluate the benefits of the ternary blend.

Detailed Description of the invention

It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. In addition, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

The use of "including", "comprising" or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. Further, the use of terms "first", "second", and "third", and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

The invention is based on the development of a ternary blended concrete mix, which incorporates Portland cement, silica fume, and zeolite in specific proportions to optimize both environmental and mechanical performance. The concrete mix is designed to reduce the environmental impact by lowering the use of Portland cement, thereby reducing CO₂ emissions associated with concrete production.

Raw Materials:

i) Portland Cement: The primary binder material in the concrete mix, typically comprising between 70% and 85% by weight of the total binder content.

ii) Silica Fume: Silica fume is used to enhance the mechanical properties and durability of concrete. It improves the microstructure by filling the voids in the concrete matrix and contributes to the formation of calcium silicate hydrate (C-S-H) gel. Silica fume also reduces the permeability of concrete, making it more resistant to water and chemical penetration.

iii) Zeolite: Zeolite is used as a supplementary material to improve the overall sustainability and performance of the concrete. Its natural pozzolanic properties allow it to react with calcium hydroxide (Ca(OH)₂) produced during the hydration of Portland cement to form additional C-S-H gel. Zeolite can also reduce the heat of hydration, making it ideal for mass concrete applications.

iv) Blending Ratios: The ideal blend of silica fume and zeolite is between 5-20% silica fume and 5-15% zeolite by weight of Portland cement. The proportion of silica fume can be increased to enhance early strength, while zeolite helps to improve long-term durability and reduce environmental impact.

The total binder content (Portland cement + silica fume + zeolite) typically ranges from 15% to 40% of the total concrete mix by weight, depending on the application and desired performance characteristics.

Mixing and Application: The mixing process involves the standard procedure for preparing concrete, ensuring that the ternary blend of silica fume and zeolite is thoroughly dispersed throughout the mix.

The water-to-binder ratio (W/B ratio) is optimized to achieve the desired workability and strength development. A lower W/B ratio (typically around 0.3 to 0.4) is used for high-strength concrete, while a higher W/B ratio may be used for concrete requiring enhanced workability.

Curing Conditions: The concrete is cured at ambient or elevated temperatures, depending on the desired strength development and the type of structure being built.
The curing period for the ternary blend may be slightly longer than that of conventional concrete due to the slower reaction rates of the silica fume and zeolite components.

ADVANTAGES OF THE INVENTION

The method for preparing sustainable ternary blended concrete offers several advantages over conventional Portland cement-based concrete:

i) Reduced Environmental Impact: The use of silica fume and zeolite reduces the need for Portland cement, thus lowering the carbon footprint of the concrete. Both silica fume and zeolite are industrial by-products, making them sustainable alternatives that help reduce waste.

ii) Improved Durability: The ternary blend enhances the concrete's resistance to chemical attacks, shrinkage, and cracking. The combined effects of silica fume and zeolite contribute to a denser microstructure, reducing the permeability of the concrete and increasing its longevity.

iii) Enhanced Mechanical Properties: The combination of silica fume and zeolite improves the compressive strength and tensile properties of the concrete, making it suitable for high-performance applications such as pavements, bridges, and high-rise buildings.

iv) Cost-Effectiveness: By utilizing industrial by-products like silica fume and zeolite, the cost of producing concrete can be reduced while maintaining or improving the quality of the material.

It will be recognized that the above described subject matter may be embodied in other specific forms without departing from the scope or essential characteristics of the disclosure. Thus, it is understood that, the subject matter is not to be limited by the foregoing illustrative details, but it is rather to be defined by the appended claims.

While specific embodiments of the invention have been shown and described in detail to illustrate the novel and inventive features of the invention, it is understood that the invention may be embodied otherwise without departing from such principles.
, Claims:1. A method for preparing a sustainable ternary blended concrete, the method comprising:
a) mixing Portland cement with silica fume and zeolite as supplementary cementitious materials in proportions of 5-20% silica fume and 5-15% zeolite by weight of the total binder content;
b) blending the mixture with water, aggregates, and additives to form a concrete mix;
c) casting the concrete into molds and curing under controlled conditions to achieve desired strength and durability.

2. The method as claimed in claim 1, wherein the Portland cement comprises 70-85% by weight of the total binder content.

3. The method as claimed in claim 1, wherein the concrete mix is tested for compressive strength, workability, setting time, and durability after curing.

4. The method as claimed in claim 1, wherein the concrete exhibits improved resistance to chemical attack, reduced permeability, and enhanced mechanical properties compared to conventional concrete.

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