Mechanical Properties and Air Permeability of Concrete Containing Waste Tires Extracts

Nowadays, uncontrolled disposal of waste materials such as tyres can affect the environment. Therefore, careful management of waste disposal must be done in order to conserve the environment. Waste tyres can be use as a replacement for both fine aggregate and coarse aggregate in the production of concrete. This research was conducted to assess the durability of concrete containing recycled tyres which have been crushed into fine fragments to replace fine aggregate in the concrete mix. This study presents an overview of the use of waste rubber as a partial replacement of natural fine aggregate in a concrete mix. 36 concrete cubes measuring 100mm × 100mm × 100mm and 12 concrete cubes measuring 150mm × 150mm × 150mm were prepared and added with different percentages of rubber from recycled tyres (0%, 3%, 5% and 7%) as fine aggregate replacement. The results obtained show that the replacement of fine aggregate with 7% of rubber recorded a compressive strength of 43.7MPa while the addition of 3% of rubber in the concrete sample recorded a high compressive strength of 50.8MPa. This shows that there is a decrease in the strength and workability of concrete as the amount of rubber used a replacement for fine aggregate in concrete increases. On the other hand, the water absorption test indicated that concrete which contains rubber has better water absorption ability. In this study, 3% of rubber was found to be the optimal percentage as a partial replacement for fine aggregate in the production of concrete.

The global scientific research circle and government agencies face a number of serious environmental challenges, one of which is the recycling of “End of Life Tires” (ELT). An estimation of one billion tires is expected to end their useful life annually, of which only roughly 50% are recycled at the moment, with the remainder ending up in landfills. Consequently, to solve this gap in the ELT's utilization rate, it is imperative to enhance the current application and furthermore create new applications for recycled tire materials. One of such areas that is currently being investigated is the introduction of waste tire into concrete as partial replacement of natural aggregates in concrete production. This experimental study investigated the influence of elevated temperatures on the mechanical properties of M25 grade concrete, specifically its compressive strength, split tensile strength, and flexural strength. The study focused on the effect of incorporating crumb rubber as a partial replacement of fine aggregate at varying percentages 5%, 10%, 15%, and 20% along with a constant 2% of corrugated round steel fibers. After a standard 28 days water curing period, concrete specimens were subjected to a range of elevated temperatures 2000C, 4000C, 6000C, and 8000C, to simulate fire-like conditions. The results of the study revealed a significant and consistent reduction in all three mechanical properties as the exposure temperature increased, which is a common characteristic of concrete under thermal stress. However, the performance varied notably among the different mixes. For compressive and flexural strength, the concrete mix with 10% crumb rubber (CR) demonstrated superior performance, consistently retaining the highest residual strengths at higher temperatures compared to all other mixes. This finding suggests that a 10% replacement level strikes an optimal balance, where the crumb rubber helps to relieve internal thermal stresses through its melting and decomposition, while the steel fibers provide crucial internal reinforcement to prevent catastrophic failure. In contrast, the split tensile strength tests showed a different trend. The mix with 5% crumb rubber exhibited the best performance at all temperatures. This indicates that while the steel fibers effectively bridged cracks and enhanced tensile properties, higher percentages of crumb rubber led to a greater number of weak bonds within the concrete matrix, which negatively impacted its tensile strength. The study concludes that the strategic incorporation of crumb rubber and steel fibers can enhance the thermal performance of concrete, but the optimal percentage of crumb rubber is dependent on the specific mechanical property being optimized. The findings also led to recommendations for preventive measures against fire damage in concrete, such as the use of fire-resistant mixes, application of protective coatings, and ensuring adequate concrete cover over reinforcement.

Plastic is used in many forms in day-to-day life. Since Plastic is non-biodegradable, landfills do not provide an environment friendly solution. Hence, there is strong need to utilize waste plastic. This creates a large quantity of garbage every day which is unhealthy and pollutes the environment. In present scenario solid waste management is a challenge in our country. The production of solid waste is increasing day to day and causes serious concerns to the environment. In this study, the recycled plastics are used in the concrete as a partial replacement of fine aggregate in concrete. The main purpose of this study is to investigate the mechanical properties of concrete such as workability, compressive, flexural and split tensile strengths of concrete mixes with partial replacement of conventional fine aggregate with aggregate produced from plastic waste. The use of plastic aggregate as replacement for fine aggregate enhances workability and fresh bulk density of concrete mixes. The mechanical properties of concrete such as compressive, flexural, and tensile strengths of concrete reduced marginally up to 10% replacement levels.Plastic is used in many forms in day-to-day life. Since Plastic is non-biodegradable, landfills do not provide an environment friendly solution. Hence, there is strong need to utilize waste plastic. This creates a large quantity of garbage every day which is unhealthy and pollutes the environment. In present scenario solid waste management is a challenge in our country. The production of solid waste is increasing day to day and causes serious concerns to the environment. In this study, the recycled plastics are used in the concrete as a partial replacement of fine aggregate in concrete. The main purpose of this study is to investigate the mechanical properties of concrete such as workability, compressive, flexural and split tensile strengths of concrete mixes with partial replacement of conventional fine aggregate with aggregate produced from plastic waste. The use of plastic aggregate as replacement for fine aggregate enhances workability and fresh bulk density of concrete mixes. The mechanical properties of concrete such as compressive, flexural, and tensile strengths of concrete reduced marginally up to 10% replacement levels.

Concrete is mostly used construction material in the construction of structures, bridges. It contains natural aggregates and cement. The use of aggregates includes fine and coarse aggregates in concrete which is likely to deplete natural resources and also creating environmental problems. There is a need to use alternative materials which can reduce the requirement of natural resources. Nowadays, huge amount of tyre is generated as waste which creates the disposal problem. It has become a major environmental issue. Several researchers have been done to use tyre waste as an alternate material. In this paper, crumb rubber is used as a replacement for natural fine aggregates in concrete at 0, 5, 10, 15 and 20%. The compressive strength of M30 grade concrete using crumb rubber as partial replacement of fine aggregate was investigated as per IS10262-2009. The compressive strength of crumb rubber concrete was obtained satisfactory when concrete mix was made 10% partial replacement of fine aggregate with crumb rubber. In many applications, crumb rubber concrete may be useful as compared to conventional concrete in spite of less compressive strength. Crumb concrete has many desirable properties which are useful many structural applications.KeywordsConcreteCrumb rubberCompressive strengthFine aggregateWaste material

This study investigates the durability indicators for sustainable concrete produced by adding both crumbed rubber and steel fibres that are removed from waste tyres to the concrete mixes. Crumb rubber was treated by submersion in sodium hydroxide and then used to partially replace 10% and 30% of fine aggregates in the concrete mix. Extracted steel fibres were added at the rate of 1% and 2% per volume of each mix. The compressive strength was recorded, and a non- destructive air permeability test was used to assess permeation characteristics of studied specimens and to correlate the results with compressive strength results. It was found that with the increase in the steel fibres percentage while keeping the rubber content constant resulted in increased compressive strength of concrete. Rubberized concrete of 10% crumb rubber and 1% steel fibres exposed to oven drying at 105°C for 12 hours exhibited an increase in compressive strength. The addition of crumb rubber and steel fibres as a partial fine aggregate replacement resulted in increasing the air permeability of the concrete to different degrees depending on the percentages used. This study showed that waste tyres extracts can be a viable, economic, and environmentally friendly method for obtaining durable and sustainable concrete.

The Effect of Combination between Crumb Rubber and Steel Fiber on Impact Energy of Concrete Beams

Steel slag is a by-product which can be obtained from steel industry and generated as a waste during the production of steel. Besides, it has been declared a useful construction material, not an industrial waste by most of the developed countries. However, in Malaysia, the rate of utilization of steel slag is very low compared to other developed countries. This paper aims to experimentally study and investigate the effect of steel slag as partial replacement of fine aggregate incorporating superplasticizer in concrete. For this purpose, tested samples consisting of 150 mm concrete cubes and cylinder samples with 150 mm diameter and 300 mm height are prepared and mixed with superplasticizer, namely Sika Visco Crete(VC 2192). Compressive strength, split tensile strength, workability, and ultrasonic pulse velocity of concrete with replacement of fine aggregate by steel slag aggregate are examined and compared with control mix design without replacement of steel slag aggregate. The optimum percentage of replacement of fine and coarse aggregate by steel slag is found. Workability of concrete gradually increases, as the percentage of replacement increases. Yet when beyond 20% of replacement, it starts to decrease, which is found by using slump test. Moreover, compressive strength, tensile strength, and ultrasonic pulse velocity are experimentally investigated. The results point out that for conventional concrete, the partial replacement of fine aggregates by steel slag improves the compressive, ultrasonic pulse velocity, and tensile strength.

Experimental investigation on the effect of using crumb rubber and steel fibers on the structural behavior of reinforced concrete beams

Nowadays, the waste tires became a critical issue for many countries as the transportation industries increase around the world. Normally, the worn-out tires will be discarded and become an environmental threat or resourceful end product depending on the waste management of the country. Thus, the aim of this study is to investigate the effect of crumb rubber as partial replacement of fine aggregates in compressive and tensile strength of concrete. Based on the mechanical behaviour, the optimum content of crumb rubber as partial fine aggregates replacement in concrete is determined. The size of crumb rubber used in this study was between 2 mm and 3 mm with 5% to 15% replacements. The targeted strength of concrete at 28th days is 35 MPa with 0.32 water to cement ratio. The slump test was conducted to measure the workability of the mix. 24 concrete cubes with dimension of 150 mm x 150 mm x 150 mm were tested for compressive strength after 7 and 28 days of water curing. In addition, 12 cylinders (100 mm x 200 mm) were prepared for tensile strength test. Based on the results of compressive and tensile strength, generally both strengths decreased as the percentages of replacement increased. However, for 5% and 10% replacement, the targeted strength is still achieved. Hence, it can be concluded that, 10% of rubber crumb is the optimum percentages to be partial replacement of fine aggregates in concrete.

Today, scrap tire is disposed of by open burning which harms the environment. To reduce the wastage of the resource, a sustainable approach is needed to dispose of the waste tire as a partial replacement of the fine aggregate in concrete mixes. This research has been conducted with a focus on the chemical attack of an engineered cementitious composite (ECC) containing a high volume of crumb rubber in terms of durability, behaviour, and comparison with conventional concrete. Two variables have been considered in developing rubberized ECC mixtures, that is, the amount of crumb rubber as a replacement for fine aggregate by volume of 0%–30% and PVA fibres by volume of 0%–2% to cementitious materials. The resistance properties of ECC incorporating crumb rubber were investigated for 13 different variable combinations developed using response surface methodology (RSM). The experimental results revealed that the presence of crumb rubber in the ECC matrix enhanced the resistance of the ECC in both acidic and sulphate environments. It was also revealed that by incorporating 15% crumb rubber, the loss of compressive strength significantly reduced from 38% to 15%.

Researchers investigated the utilization of crumb rubber aggregate recycled from waste tire in concrete to solve the problem of discarded tire and to produce a green sustainable concrete. However, a reduction in the mechanical properties due to crumb rubber inclusion occurs. Steel fiber rubberized concrete used in this study to provide a balance between the strength loss and sustainable issue. An investigation on the mechanical properties of rubberized concrete combined with hooked – end steel fiber is presented. Rubberized concrete with different replacement ratios of crumb rubber was incorporated in plain and steel fiber concrete mixes via partial replacement of fine aggregate. Four replacement ratios (17.5%, 20%, 22.5%, and 25%) were used to investigate the effect of the partial replacement of fine aggregate by crumb rubber on the mechanical properties of plain and steel fiber concrete. In both mixes, reduction in mechanical properties was observed to be proportionate with the increment of crumb rubber. Finally, a successful combination of steel fiber and crumb rubber was obtained due to improvement of strain capacity under flexural loading.

Abstract: The aim of this study is to analyse the effect of addition of crumb rubber on the various properties of concrete. The crumb rubber is used as replacement over aggregates in the concrete mix. Crumb rubber is prepared from the scraps of tyres. In this study aggregates are replaced by 0%, 30%, 40%, 60%, 100% crumb rubber. The rubberized concrete is tested for slump and compression strength. It is found that the slump of rubberized concrete increases first but as the amount of rubber is increased the slump starts decreasing. It is observed that initial compression strength of rubberized concrete reduced significantly but the final strength is found to be more than that of ordinary concrete. Waste tyres cause tremendous pressure and ecological issues for the entire tyre industry when accumulated in cultivated land or combusted. Crumb rubber (<5 mm) grinded from waste tyres was introduced to substitute for natural fine aggregate in concrete and effectively solves the consumption challenge. This paper reviews the performance of concrete with crumb rubber as fine aggregate, providing evidence for crumb rubber concrete (CRC) materials design and application. Crumb rubber is characterized with light specific gravity, hydrophobicity and air entrapment in comparison with natural fine aggregate, inducing significant reduction in workability of fresh CRC and exhibiting poor bonding performance with cementitious matrix. By summarizing the compressive/tensile strength, elastic modulus and fracture behaviour of CRC at various rubber content, prediction models of strength reduction factors are proposed. The main reasons for strength deterioration are weak interface transition zone (ITZ) performance and non-uniform distribution of rubber particles. Water/chloride permeability, electrical/carbonation resistance and drying shrinkage of CRC are discussed for durability performance of CRC. Physical/chemical pre-treatments of rubber could alleviate the hydrophobicity and improve the mechanical and durability performance of transition zones between rubber and cement paste. Accordingly, scopes concerning the recycling of crumb rubber and its performance optimization are expected in future studies.

The rate of waste tire generation globally continues to escalate due to increase in vehicle usage. Scrap tires continue to pose serious environmental, health and aesthetic problems. Due limitation in the recycling of scrap tires, one of the most viable solution is to used crumb rubber from scrap tire as partial replacement to fine aggregate in concrete industry. This is rationalized as the production of concrete hit more than 3.8 billion cubic meters annually, therefore, it could provide a solution on conservation of natural aggregate and as well as improve properties of concrete. However, the major setback in the use of crumb rubber in concrete is loss in strength. In this paper, crumb rubber was used to partially replaced fine aggregate at 0%, 10%, 20% and 30% by volume in roller compacted concrete for pavement applications to produce roller compacted rubbercrete (RCR) to improve its flexural strength and ductility. Several trials were done to achieve the combined grading as recommended by ACI 211.3R, and finally a combination of 55% fine aggregate, 40% coarse aggregate and 5% fine sand as mineral filler was used. In order to mitigate the effect of strength loss, silica fume and fly ash were used to replace natural fine sand as mineral fillers. The Results showed that fresh density, compressive, splitting and flexural strengths decreases with increase in partial replacement of fine aggregate with crumb rubber. However using silica fume as a mineral filler was successful in mitigating loss in compressive, tensile and flexural strengths for up to 20% crumb rubber replacement level, while fly ash as a mineral filler mitigated loss in strength for up to 10% crumb rubber compared natural fine sand mineral filler. The flexural strength was found to increase with 10% crumb rubber for all type of mineral filler

Production of cement generates a huge amount of carbon dioxide emissions into the environment, utilization of pozzolanic materials in concrete is a better solution for this environmental problem. Several studies are conducted for using of pozzolanic materials such as fly ash, ground granular blast furnace slag, and silica fume as a pozzolanic material in concrete. A few studies were available on using bentonite in concrete. Bentonite is mainly clay contains rich amount of silicain which obeys the pozzolanic properties. The objective of present study is to find out the effectiveness of using bentonite and waste rubber crumb in the design mix of concrete. An experimental investigation is performed on concrete mixtures to study the effect of using bentonite as a partial replacement of cement and conducting an environmentally friendly concrete using crumb rubber in the concrete mixtures as a partial replacement of fine aggregates. Cement is partially replaced by volume (2%, 5%, 10%, 15%, 20%) with Bentonite and fine aggregate is partially replaced (5%, 20%, 25%, 30%, 40%) with crumb rubber. Slump tests were conducted to evaluate the workability of fresh concrete. Compressive strength of cubes at 7days and 28 days, splitting strength and abrasion strength at 28 days are studied and compared with conventional concrete. A part of research work addresses the effect of using bentonite and waste rubber crumb on durability of concrete. For this purpose, specimens were submerged in solution containing 50 g/l of NaOH and H2SO4. Based on the test results, the ideal percentage of mix which shows maximum compressive strength is identified. The results showed that the compressive strength of the concrete was generally increases when bentonite replaced a part of the cement and decreases with the replacement of fine aggregates by the waste crumb rubber. Although the using of bentonite and crumb rubber decreases the compressive strength. The optimal mixture from the laboratory experimental investigation is 5% reduction of cement content and 20% of fine aggregates replacement that exhibited a compressive strength of 30 MPa at 28 days. The test results substantiate the feasibility to develop environmentally friendly concrete using bentonite and crumb rubber in the concrete mixtures. فى هذا البحث ،تم دراسة استخدام البنتونیت کبدیل جزئی للأسمنت ومخلفات المطاط کبدیل جزئى للرکام الناعم فى الخرسانة الصدیقة للبیئة، تم مقارنة نتائج إختبارات قابلیة التشغیل ومقاومة الضغط و مقاومة الشد الغیر مباشر (الانفلاق) ومقاومة البرى والإستدامة بالخرسانة التقلیدیة.أوصت الدراسة بإمکانیة إستخدام البنتونیت حتى 5% کبدیل للأسمنت وإستخدام مخلفات المطاط حتى 20% کبدیل للرکام الناعم فى الخلطات الخرسانیة.

The use of waste material as a partial replacement has become popular in concrete mixture studies. Many research has utilized waste materials like cement, fine aggregate, coarse aggregate, and reinforcing materials substitute. The current paper focuses on some of the waste elements that are utilized in a concrete mortar (use in roof tile) as a partial replacement for fine aggregates such as rubber ash, sawdust, seashells, crumb rubber, pistachio shells, cinder sand, stone dust, and copper slag. There are many variations of mix proportion and water-cement ratio for every waste material. Compressive strength was compared and found that stone dust and the combination of seashell and coconut fiber shows an incensement when used to replacing fine aggregate. The suitable replacement level for stone dust is 25% and 50%. While the suitable replacement levels for the combination of sea shell and coconut fiber are 20% and 30%. Material from the rubber families such as rubber crumb and rubber ash is only suitable for replacement levels. Rubber families especially rubber crumbs have shown low water absorption value which is good in the production of roofing products. As we know, the roof should have waterproof properties to prevent any leaks from happening when it rains. Most of the waste materials added as fine aggregates in concrete have increased the amount of water absorption and found that sawdust is the most abundant material with a high percentage of water absorption compared to the others. Research on the partial replacement of fine aggregates replaced with waste materials is needed more extensively to provide more confidence about their use in concrete mortars, especially on roof tiles.