Waste fibers for enhancing concrete strength performance that are used without being subjected to any treatment

Abstract

This invention relates to waste fibers that used as they are, without any treatment, to enhance the strength performance of concrete used in structures where flexural strength is important.

Description

[0001] WASTE FIBERS FOR ENHANCING CONCRETE STRENGTH PERFORMANCE THAT ARE USED WITHOUT BEING SUBJECTED TO ANY TREATMENT

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to waste fibers that used as they are, without any treatment ( / processing), to enhance the strength performance of concrete which can be used in structures where flexural strength is important.

[0004] STATE OF THE ART

[0005] It is known that the flexural strength of conventional concrete is approximately one- tenth compared to the compressive strength. Flexural strength is of great importance in terms of both strength and service life of concrete (Biricik O., et al., 2023). Both micro and macro sized fibers are used to increase the flexural strength of the concrete. These fibers used increase the performance of the concrete by showing different functions according to their size. However, the production processes of the fibers used are long and costly. For example, polypropylene fibers are produced by melting and shaping polymer raw materials at high temperatures. Although basalt fibers are produced from nature, very high temperatures are used to bring them to the fiber length. Considering the global climate crisis, it advocates for researching alternative products instead of those that consume high energy in their production. Accordingly, the use of materials generated as waste in the production of another product as a substitute for materials produced with high energy requirements provides significant advantages.

[0006] In prior technical research, it has been observed that waste fibers have been used in some studies. One of the document found in the research is numbered RU2781487C1 and is related to light fiber reinforced concrete based on industrial wastes. In the document numbered RU2781487C1 , it is seen that waste classified as hazardous from production and consumption were used in a study specified as a similar study.

[0007] Another document is numbered CN112408827B and relates to recycled concrete and its preparation method.

[0008] Another document is numbered CN114507044B and is related to high strength environmentally friendly concrete and its preparation method.

[0009] Although the said 3 documents are similar in subject, the advantages in terms of the solutions they offer and the materials used do not meet what is requested in terms of the advantage, material and solution in our current application.

[0010] DESCRIPTION OF THE INVENTION

[0011] The invention eliminates the disadvantages described in the state of the art and meets the needs.

[0012] The present invention relates to waste fibers that are used as is without any treatment to increase the strength performance of concrete, which can be used as an alternative to reinforcement fiber in structures, beams and floors where flexural strength is important.

[0013] Regarding the present invention, when we consider the differences from the similar issues primarily mentioned in the state of the art;

[0014] In said document numbered RU2781487C1 in the state of the art, it is seen that waste classified as hazardous from production and consumption are used. It is known that the waste materials used in our application does not have any hazards. In the document CN112408827B, it is seen that the fibers specified as waste are subjected to pretreatment by mixing with various materials. In this respect, the said invention differs from our application in terms of similarity.

[0015] In the document CN114507044B, asbestos fibers that are classified as potentially hazardous are used as in document RU2781487C1. It is seen that our invention proposal different from it with the fibers that does not contain any danger.

[0016] It is known that the tensile strength of concrete is quite low compared to the high compressive strength performance (Latifi et al., 2021 ). Improving the mechanical performance of concrete, which is a brittle material, by creating a more ductile structure with the use of fiber is a commonly researched subject (Mardani- Aghabaglou et al., 2018). It has been understood that it uses various types of fibers such as steel, basalt, polypropylene and polyethylene in concrete. The fibers used are expected to improve concrete strength, crack control, deformation capacity, impact strength and durability depending on many parameters such as type, length, slenderness ratio, geometry, amount of use, tensile strength and surface properties (Mardani-Aghabaglou et al., 2019; Yazici §, et al., 2023). In concrete composition, it is important to investigate fibers that are completely waste and can be used without any pretreatment, both in terms of allowing waste reuse and contributing to the circular economy (Durgun et al., 2022). Textile materials are commonly used in concrete mixtures thanks to their advantages such as lightness, flexibility, ease of procurement, antibacterial properties, durability and manufacturability in desired sizes (Mardani-Aghabaglou et al., 2013). It is understood from the literature that various surface modification processes are applied to fibers created from textile waste to prevent them from adversely affecting the fiber-matrix bond. It has been emphasized that plasma, UV, ozone and UV-ozone surface modification are the main processes performed for this purpose. However, waste fibers that can be used in concrete composition should be investigated without the need for additional processing (treatment) in terms of both energy used and cost. It can be seen from Table 1 that the waste fibers used within the scope of our application increase the compressive and flexural strength performance of the concrete. In addition, the effect of fibers on the workability performance of cemented systems is shown in Figure 1 . The naming of the blends in the Figure and Table is based according to the fiber type and fiber dosage contained in the blend. For example, fiberl -25 is characterized as a blend containing 0.25% of air conditioning dust waste. In addition, each fiber was used separately to more clearly examine the performance of the fibers in the prepared cemented systems.

[0017] Each result obtained is given as the average of 3 samples.

[0018] Table 1 . Compressive and flexural strength results of concrete produced using fiber

[0019] Graph 1 . Workability performances of the mixtures The properties of the waste fibers are below:

[0020] DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention is waste fibers that used as they are, without any treatment, added to the production of concrete to increase the strength performance of concrete, characterized in that; these fibers used are comprised of at least one of the following types of fibers

[0022] • air conditioner waste fiber accumulated in air conditioner ducts in spinning mills, comprising 40-60% cellulose and 40-60% dust gin trash

[0023] • feeder fiber consisting of cotton-rich waste accumulated under the compactor in the production of OE yarn (Open-end yarns are yarns that are mostly produced from short fibers) approximately 68% cellulose and 32% cottonseed, gin trash, dust materials

[0024] • subduct fiber comprising 45-70% cotton and 30-55% PES blended strip, wick and lint accumulated under the channel in ring yarn production,

[0025] In the invention, at least one of said fibers mentioned in the production of concrete is mixed at a percentage of 0-0.1 by weight.

[0026] In the invention, at least one of said fibers mentioned in the production of concrete is mixed at a percentage of 0.025-0.05 by weight.

[0027] In the present invention, the following method steps are basically used in the preparation of concrete;

[0028] A. The mixing of water-cement

[0029] B. The addition of aggregate and fiber with said properties into the mixture

[0030] C. Pouring into molds.

[0031] It’s detailed explanation is; Water and cement are mixed after being weighed. They are mixed at the speed of 62.5 revolutions / minute for 30 seconds. Then aggregate and fibers are added together and mixed for 30 seconds at the same speed. The speed is increased, and mixing goes on for 30 more seconds. The mixture is rested for 1.5 minutes. Afterwards, it is mixed again at 125 revolutions / minute for 1 more minute. Then, it is placed into molds. The mixture should not be mixed for more than 3 minutes in total.

[0032] The use of waste materials as fibers in concrete mixtures both enables the production of high-performance concrete and prevents environmental pollution. In this context, it has been understood that many innovative studies on concrete mixtures produced with the use of plant, animal and textile waste fibers are available in the literature. However, in most of the studies, it was understood that the fibers underwent some processes before they were used. It is clear that this situation negatively impact on sustainability in terms of energy, time and cost.

[0033] In this invention, the mechanical properties of the mixtures have been improved by using 3 different fibers, which are completely waste without any processing (treatment), separately in different proportions of concrete mixture. The mechanical properties of concrete mixtures have been improved by providing energy conservation, reducing the amount of waste and contributing to the economy.

Claims

CLAIMS1 . The invention is waste fibers that used as they are, without any treatment, added into concrete production to enhance the strength performance, characterized in that; these fibers that used are comprising at least one of the following types of fibers:• air conditioner waste fiber accumulated in air conditioner ducts in spinning mills, comprising cellulose and dust, gin trash• Feed fiber consisting of cotton-rich waste cellulose and cottonseed, gin trash, dust materials accumulated under the compactor in the production of OE yarn (Open-end yarns are yarns that are mostly produced from short fibers)• Sub-duct fiber comprising cotton and PES blended strip, wick and lint accumulated under the channel in ring yarn production.

2. Waste fibers that used as they are, without any treatment, added into concrete production to enhance the strength performance according to claim 1 , characterized in that; these fibers that used are comprising at least one of the following types of fibers:• air conditioner waste fiber accumulated in air conditioner duct in spinning mills, comprising 40-60% cellulose and 40-60% dust and gin trash,• feeder fiber consisting of cotton-rich waste accumulated under the compactor in the production of OE yarn (Open-end yarns are yarns that are mostly produced from short fibers) approximately 68% cellulose and 32% cottonseed, gin trash, dust materials• sub-duct fiber comprising 45-70% cotton and 30-55% PES blended strip, wick and lint accumulated under the channel in ring yarn production.

3. Waste fibers according to claim 1 , characterized in that; at least one type of fiber is comprised in concrete production content in a ratio of 0-0.1 by weight.

4. A method for adding waste fibers that used as they are, without any treatment, into concrete production to enhance the strength performance, characterizedin that; at least one of the following fiber types is added to the mixture together with aggregate after water-cement has been mixed before they are poured into molds:• air conditioner waste fiber accumulated in air conditioner ducts in spinning mills comprising cellulose and dust, gin trash,• Feed fiber consisting of cotton-rich waste cellulose and cottonseed, gin trash, dust materials accumulated under the compactor in the production of OE yarn (Open-end yarns are yarns that are mostly produced from short fibers)• Sub-duct fiber comprising cotton and PES blended strip, wick and lint accumulated under the channel in ring yarn production.

5. The method for adding waste fibers that used as they are, without any treatment, into concrete production to enhance the strength performance according to claim 4, characterized in that; at least one of the following fiber types is added to mixture together with aggregate after water-cement has been mixed before they are poured into molds:• air conditioner waste fiber accumulated in air conditioner ducts in spinning mills comprising 40-60% cellulose and 40-60% dust and gin trash,• feeder fiber consisting of cotton-rich waste accumulated under the compactor in the production of OE yarn (Open-end yarns are yarns that are mostly produced from short fibers) approximately 68% cellulose and 32% cottonseed, gin trash, dust materials• sub-duct fiber comprising 45-70% cotton and 30-55% PES blended strip, wick and lint accumulated under the channel in ring yarn production.

6. The method for adding waste fibers that used as they are, without any treatment, into concrete production to enhance the strength performance according to claim 4, characterized in that; after mixing water and cement, and before pouring into molds, the mixture is stirred for 30 seconds at the same speed while adding the aggregate, then increase the speed and mixed for another 30 seconds and after resting the mixture for 1 .5 minutes, it is stirred for an additional 1 minute at 125 rpm.

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