AMBIENT TEMPERATURE PRODUCTION METHOD OF SILICA FUME-BASED HYBRID GEOPOLYMERS CONTAINING TUFF

Abstract

The invention relates to a method for producing low-carbon, environmentally friendly hybrid geopolymer-based building materials that can be cured at ambient temperature, as an alternative to Portland cement, in the fields of civil engineering and materials science.

Description

ENVIRONMENTAL EFFECTS OF SILICA FUME-BASED HYBRID GEOPOLYMERS CONTAINING TUFF PRODUCTION METHOD AT HIGH TEMPERATURE TECHNICAL FIELD The invention is in the field of civil engineering and materials science, related to Portland cement. Alternatively, it can be cured at ambient temperature, is low-carbon, and environmentally friendly. This relates to the production method of environmentally friendly hybrid geopolymer-based building materials. PREVIOUS TECHNIQUE Portland cement, the most widely used binder in the construction industry today, The production process involves both high energy consumption and significant carbon emissions, negatively impacting the environment. It has become a material that causes pollution. Every ton of cement produced contributes to global pollution. While responsible for a significant portion of CO₂ emissions, sustainable construction The need for these materials is becoming more and more apparent every day. At this point Geopolymers are high-strength and environmentally friendly with a lower carbon footprint. It stands out as an alternative. However, most existing geopolymers require high temperatures to set. This is necessary in terms of energy saving and on-site implementation. It fails to provide the expected ease of use, especially in countries like Türkiye where natural pozzolanic rocks are located. In countries with abundant resources, volcanic rocks such as tuff and fine silica fumes are found. The efficient use of mineral additives in these systems has great potential. It carries. Nevertheless, when these materials are used in appropriate proportions, the environment Research into systems that can harden (set) by curing at high temperatures is still ongoing. It is quite limited. This gap is filled by a new product that is both environmentally friendly and can be produced from local resources. This highlights the need for the development of next-generation connecting systems. In short, construction In order to achieve a green transformation in the sector, high-performance but There is an urgent need for environmentally friendly geopolymer formulations that can harden at ambient temperatures. It is needed in this way. THE PURPOSE OF THE INVENTION The invention relates to geopolymer-based hybrid binder systems at ambient temperature. It offers a new production approach that enables hardening of existing geopolymers. 1 While most require high-temperature curing, this system eliminates the need for high-calcium additives. Significantly reduced, low carbon footprint using only 5% cement. Emission-efficient and economical production is targeted. Silica fume is used as a binding agent and Tuff was preferred; in the literature, geopolymers can be obtained from these raw materials at ambient temperature. While it was not possible to do so before, this obstacle is overcome thanks to special formulation and production methods. This has been exceeded. Geopolymer samples obtained were subjected to pressures of 70 MPa and above in 28 days. The strength has been achieved; these strengths are obtained without additional heating or steam curing. It has been done. The most important feature of the method described in the invention is that it can produce high-performance products without requiring heating on site. It enables the production of a product with mechanical properties. Thus, not only A structure suitable for on-site production and application, not limited to prefabricated facilities. The material has been improved. The materials used are based on existing ready-mixed concrete and mortar production. They can be produced in the facilities without requiring additional equipment; this reduces both energy consumption. It also reduces production costs. In addition, the composition of the mixture is suitable for the project. It is adaptable to the specific requirements. Thus, the fresh mix is ​​ready for use in the field. It can be prepared and used in practice. The developed hybrid geopolimer system is suitable for construction, repair, reinforcement, and prefabrication. It can be applied in various fields such as component manufacturing. It can be cured at ambient temperature. Thanks to its (ability to plug into a power outlet) feature, it not only facilitates production; it also at the same time, in line with sustainability goals, low cost, energy efficient and environmentally friendly. It offers an environmentally friendly building material solution. DETAILED DESCRIPTION OF THE INVENTION The invention is a device that hardens at ambient temperature without requiring high-temperature curing. It is aimed at developing a new generation geopolymer binder system (capable of setting). Today, the integration of geopolymers into construction industry applications is... The most significant challenge is the thermal energy required for curing. The method described in this invention addresses this issue. By eliminating the problem, we both increase energy efficiency and improve production processes. It makes it more practical and easier. Binding material and basalt sand used in the production of hybrid geopolymers. The quantities used are in the ratios specified in the TS EN 196-1 standard. The method described in the invention. Portland cement constitutes only 5% of the total binder material. This has been used and as a result, the environmental impact of cement has been significantly reduced. The Portland cement used is of type CEM I 42.5 R and conforms to the TS EN 197-1 standard. 2 It is suitable. The specific gravity of cement is 3.13, and the specific surface area of ​​BET is 1.834 m² / g. Silica fume was used as the primary binder material in the binding system. Other The tuff, which is the binding component, constitutes 10%, 20%, 30%, and 40% of the total binder amount. It was used in proportions. Produced with binding materials and basalt sand. The hybrid geopolymer binder system offers high performance even when cured at ambient temperature. It forms a structure that will provide mechanical properties. Silica fume has a specific gravity of 2.37. and has a specific surface area of ​​20,897 m² / g BET. It is sourced from the Nevşehir region. The tuff was calcined at 750°C and ground in a steel ball mill. The calcined tuff... The specific gravity is 2.60, and the specific surface area is 11.3038 m² / g. These two materials, High surface area and reactive structure properties that support the geopolymerization process. Thanks to silica, it enables the formation of a binding structure without the need for heating. The smoke has an amorphous structure, a high specific surface area, and a high purity SiO₂ content. It reacts readily with alkaline activators. This situation affects sodium. OH⁻ ions in the hydroxide and sodium silicate solution reach the silica surface more quickly. penetration and the dissolution of Si–O bonds, transforming them into active silicate species. This facilitates the process. Similarly, since tuff is purified from crystalline phases by calcination... It acquires reactive aluminosilicate structures. This structure, Al–O–Si, is formed even at ambient temperature. breaking of bonds and early formation of a three-dimensional geopolimer network This makes it possible. Thus, the overall reaction kinetics of the system are accelerated, and the gel phase (N-A-S-H type) is developing rapidly and in classic systems it is only possible with heating. The matrix density that can be provided at room temperature within the scope of the invention This happens. Thus, at the end of the 28-day course, pressure of 70 MPa and above is achieved. The required strengths have been achieved, eliminating the need for conventional steam curing or heat treatment. Basalt sand was used as aggregate in the geopolimer system. Basalt aggregate, It is sourced from the Altunhisar region of Niğde and after being washed and dried... It was crushed. Then it was sieved through 2 mm or smaller sieves and the basalt sand gradation was determined using TS (Turkish Standards Institution). It has been adjusted according to the limit values ​​specified in the EN 196-1 standard. Basalt sand. Its density is 2.77 g / cm³. The developed method primarily uses silica fume, tuff, Portland cement, and basalt. The sand, in its dry state, was mixed in a blender to create a homogeneous mixture. This This stems from differences in density and grain size of the materials at each stage. A controlled mixing process was applied to prevent separation. The controlled mixing process ensures that each component of the mixture is mixed evenly and homogeneously. The mixing speed, duration, and sequence must be predetermined to ensure even distribution. 3 This means it will be implemented in a defined manner. In this process, first at a low speed. by mixing, binder materials (silica fume, tuff and Portland cement) and A dry, homogeneous mixture of basalt sand is prepared. This ensures that any part of the mixture is not damaged. No density difference or clumping occurs at any point; it is homogeneous and A repeatable structure is obtained. Then sodium hydroxide (NaOH), sodium A solution consisting of a mixture of silicate (Na₂SiO₃) and water is prepared. Na₂SiO₃... Its density is 1.41 g / cm³, and its composition is 65.5% water, 23% SiO₂, and 11.5% Na₂O, respectively; solid. NaOH, on the other hand, is 97% pure and has a density of 2.12 g / cm³. The prepared dry homogenous The mixture and solution are mixed in a mixer. The alkaline solution, silica in the mixture, and By dissolving the alumina phases, they initiate geopolymerization reactions and three It enables the formation of a three-dimensional network structure. All mixtures are fed into the mixer. After the additions, the mixture is stirred first at a low speed and then at a high speed. Homogeneous distribution of the components is ensured. The mixture is first mixed at a low speed, then... high-speed mixing, due to differences in density and particle size of the components It prevents the resulting separations, thus ensuring the formation of a homogeneous structure. The fluidity (workability) of the mixture with a low water / binder ratio. to provide a polycarboxylic ether-based superplasticizer additive This additive is used to increase the fluidity of the fresh batter, making it easier to pour the mixture into the molds. It ensures settling and also the density and surface area of ​​the mixture. It improves its smoothness. At the low speed stage, coarse-grained and heavy components (e.g., basalt sand and (cement) is evenly distributed in the mixture; this stage prevents the materials from settling. or prevents clumping. Then high-speed mixing is applied, fine-grained and light components (e.g., silica fume and tuff) make up the entire volume of the mixture. This ensures an even distribution. This change in speed provides both physical and... The interaction between the chemical components is increasing, the alkaline activator solution all they penetrate surfaces and geopolymerization reactions are more efficient This occurs. As a result, components with different densities separate without... By ensuring proper mixing, a homogeneous, repeatable and high-strength binder is obtained. The fresh mixture is then processed using a vibrating table measuring 40×40×160 mm. They are placed in molds of a certain size, thus eliminating air gaps in the mixture. The density is minimized and a dense structure is obtained. The hybrid geopolymer produced. The samples are left at room temperature for 24 hours, during which time Portland The limited amount of calcium ions provided by the cement inhibits early age reactions. 4 It helps to complete the erection process by providing support. Scientifically, "ambient temperature" is generally between 20°C and 25°C. It refers to the temperature range between [the specified range]. This range is used in materials science and chemistry. In engineering literature, the standard for experiments performed under laboratory conditions It is considered the reference medium. Therefore, the samples are kept in this medium for 24 hours. Keeping it within a temperature range, curing at ambient temperature is scientifically defined as... This corresponds to the technical effect arising from the method described in the invention, silica fume, tuff. This is due to the synergistic behavior created by the combination of low-percentage cement and the cement itself. Silica fume, thanks to its high specific surface area and high amorphous silica content. It dissolves rapidly in an alkaline environment, forming reactive silicate phases. Tuff is a natural substance. As an aluminosilicate material, it combines with these phases to form a three-dimensional geopolymer network. It supports the formation of its structure. It is used in the system at a rate of only 5%. Cement, with its calcium components, completes this network structure, thus creating the environment. This enables hardening at high temperatures. Thus, the curing process of the system is achieved at high temperatures. This occurs without requiring energy. This situation is consistent with classic geopolymers. By eliminating the 60–90 °C temperature requirement seen in systems, it saves energy. It saves money and also makes field applications possible. Another technical effect brought about by the invention is that despite the low water / binder ratio... The goal is to maintain the processability of the mixture. Polycarboxylic ether-based superplasticizer. The additive increases the fluidity of the mixture, allowing the fresh batter to easily settle into the molds. This additive increases the density and surface smoothness of the mixture. The final strength values ​​also increase. In addition, basalt sand is used as a filling material. Using it as such reduces the porosity, thereby improving both the mechanical properties of the samples. It also strengthens its chemical resistance. Consequently, the invention eliminates the need for energy-intensive processes such as heat or steam curing. a high-strength geopolymer that hardens at room temperature without being detected It enables the material to be obtained. The developed system uses low amounts of cement. It reduces environmental impact and recovers silica fume, an industrial waste. It ensures, promotes the efficient use of local natural materials and thus provides sustainability. It offers a new solution in terms of building technologies. Thanks to this, geopolimer technologies, It can be easily applied not only in laboratory settings but also on construction sites. will become.

Claims

1. Production of tuff-containing silica fume-based hybrid geopolymers at ambient temperature. It is a method, and its characteristic is; - Silica fume, tuff, Portland cement, and basalt sand at low speed. ensuring homogeneous mixtures, - Sodium hydroxide (NaOH), sodium silicate (Na₂SiO₃), and water with alkali. Preparation of activator solution, - Prepared with dry binder materials and basalt sand. The homogeneous mixture is mixed at low speed with the alkaline activator solution. ensuring homogeneous mixtures in the mixer, - To ensure the fluidity of the mixture with a low water / binder ratio. for the purpose of adding a polycarboxylic ether-based superplasticizer to the mixer addition, - In the mixer, all mixtures are first mixed at low speed and then... homogeneity and fluidity are ensured by mixing at high speed. - The resulting homogeneous mixture is poured into molds using a vibrating table. placement and compression, - Allowing the geopolymers placed in the molds to set for 24 hours. for this purpose, it should be left at room temperature and the binding materials ensuring it hardens, - The stages of removing hardened geopolymers from the molds. It is characterized by its inclusion.

2. The method according to Claim 1, its characteristic feature is that the proportion of tuff as a binding material, It is characterized by having a total binder content ranging from 10% to 40%.

3. The method according to Claim 1, characterized by its use of Portland cement as a binder. It is characterized by its ratio being 5% of the total binder amount. 6