scholarly journals Experimental Study on Mechanical Performance of Recycled Fine Aggregate Concrete Reinforced With Discarded Carbon Fibers

2021 ◽  
Vol 8 ◽  
Author(s):  
Osama Zaid ◽  
Syed Roshan Zamir Hashmi ◽  
Fahid Aslam ◽  
Hisham Alabduljabbar

With the development of technology in every field, it is necessary to recommend an eco-friendly material to be utilized in the construction industry. Recently, using waste/recycled materials in the concrete as a substitute is a trend to bring sustainability to the construction industry, but the recycled/waste materials has poor mechanical properties, thus to enhance these poor properties, this research studies the mechanical performance of sustainable concrete incorporating waste materials as aggregates, the study is performed in the three stages. In the first stage, the natural sand was substituted with recycled sand in the percentage of 0, 35, 70, and 100%, and all the tests i.e. compressive strength, split tensile strength and flexural strength were performed on concrete which was cured in water for 28 days. As the 35% substitution of natural sand with recycled fine aggregate presented the optimum mechanical performance, it was selected for the third stage of the research. In the second and the third stages, the discarded carbon fibers were utilized in concrete with 2, 4, and 6% by weight. A total of 90 samples were prepared for this research, in which 30 samples were cubes, 30 samples were cylinders and 30 samples were beams, all the samples were tested at 28 days. Comparative analysis was performed to validate and verify the results of this paper with the relevant literature. The SEM test was also performed on a fractured concrete surface to study its microstructure. The outcome of tests revealed that the utilization of discarded carbon fibers in concrete enhances compressive, split tensile and flexural strength by 27.8, 17.8, and 35.9% and acts as a crack bridging and also restrain the propagation of the first cracks. Fibers also helped the concrete to improve its energy absorption capacity and ductility.

2012 ◽  
Vol 253-255 ◽  
pp. 432-435
Author(s):  
Jiu Su Li ◽  
Chun Li Qin

Fine aggregate can be extracted from waste concrete by series of processing. The recycled fine aggregate can then be utilized to manufacture recycled fine aggregate mortar (RFAM) or recycled fine aggregate concrete (RFAC). Air entraining agent was added in RFAM to improve its mechanical performance. The influence of the dosage of the air entraining agent on both the compressive and flexural strength of the RFAM was explored after 7 days and 28 days curing. The optimum dosage of the air entraining agent was determined.


2021 ◽  
Vol 894 ◽  
pp. 95-101
Author(s):  
Sepehr Ghafari ◽  
Fereidoon Moghadas Nejad ◽  
Ofelia Corbu

In this research, a sustainable approach is followed to develop efficient mixtures incorporating recycled fine aggregate (RFA) remained from structure demolition as well as limestone filler (LF) from production of hot mix asphalt (HMA). The LF is a byproduct of the drying process in HMA production plant which is not entirely consumed in the production of the HMA and must be hauled and disposed in landfills. The maximum particle size of the LF is approximately 40 µm. Self-Compacting Concrete (SCC) mixtures were designed replacing 5% and 10% of the cement with LF. Incorporation of 50%, and 100% RFA with the fines in the mixtures were considered with and without addition of the LF. Due to the formwork and prefabrication restrictions, the paste volume and the high range water reducer content were tuned in such a way that the slump flow of the mixtures remained between 660 mm to 700 mm without segregation. Durability and mechanical performance of the mixtures were evaluated by resistance against freeze-thaw scaling exposed to deicing agents and compressive strength. It was observed that the SCC mixtures containing 10% LF outperformed those without the use of LF while 5% SCC mixtures did not exhibit tangible superiority. Incorporation of RFA as the fine fraction degraded the durability of all the mixtures. While replacing all the fine fraction with RFA significantly impaired durability and compressive strength, 50% RF mixtures could be designed containing 10% LF that remained in the allowable limits.


2018 ◽  
Vol 760 ◽  
pp. 193-198 ◽  
Author(s):  
Kristina Fořtová ◽  
Tereza Pavlů

This paper presents research results of recycled fine aggregate concrete testing. The main aim of this contribution is verification of properties of fine aggregate concrete with partial replacement of fine natural aggregate by recycled masonry aggregate originated from construction and demolition waste. The influence of partial replacement of natural sand to mechanical properties and freeze-thaw resistance is described. The compressive strength and flexural strength were tested at the age of 28 and 60 days and after 25, 50, 75 and 100 freeze-thaw cycles. Partial replacement of natural sand was 0, 25 and 50 % for all these tests. Prismatic specimens were examined.


Conventionally used cement –a primary binder also a necessitate element in producing concrete rates first in the construction industry. Production of conventional cement requires a greater skill and is energy intensive. The usage of waste materials in the production of concrete and reduction in cement content was only the possible alternative in the past decade. Associated risks with the production of Ordinary Portland Cement are well known. A greener aided with a natural friendly claim can be made only with the usage of the waste materials and reduction in evolving respiration gas to the atmosphere. Almost all works are carried out using source material fly ash, with fine aggregate and coarse aggregate. Concrete plays a vital role in the construction industry and on the other hand, river sand; one of the essential material has become very expensive which is a scarce material. Depletion of sand is a hectic issue due to increased usage of sand in construction. No other replacement materials such as quarry rock dust is not concentrated in casting geopolymer specimens. Even though in some research papers the replacement materials are added only in partial replacement without aiming on 100% replacement. Many researches mainly focus towards test results of GPC specimens using steel fibers, glass fibers. But the study related to natural fibers and hybrid fibers are found scarce. The main part of this work aimed at characterizing the engineering strength properties of geopolymer concrete by 100% replacement of fine aggregate with quarry rock dust. Hence, combination of flyash and quarry rock dust in GPC have been considered for evaluating the mechanical properties of geopolymer concrete. Also, investigation focuses on incorporation of three different fibers namely polypropylene fibers(PF), coir fibers(CF) and hybrid fibers(HF) in different percentage of proportions such as 0.5%,1%,and 1.5% to determine the maximum strength properties of GPC.


Concrete is a material which widely used in construction industry. The present investigation deals with the study of partial replacement of fine aggregate by Nylon Glass Granules in concrete. The fine aggregates are replaced by 0%, 10%, 20% and 30% by Nylon Glass Granules by volume of natural sand in M35 grade of concrete. Additionally, to increase the tensile strength of concrete 1% of Steel Fiber by volume of cement were added to all the mixes containing Nylon Glass Granules. The concrete produced by such ingredients were cured for 7 and 28 days to evaluate its hardened properties. The 28days hardened properties of concrete revealed that maximum strength is observed for the mix which possesses 20% replacement of fine aggregate by Nylon Glass Granules compared with the conventional concrete, thus it is said to be the optimum mix


Disposal problem of waste materials and excessive demand on naturally available resources due to rapid urban development has opened possibilities for use of waste materials in construction industry. Many waste materials are used in concrete as replacement to cement, fine aggregate, coarse aggregate and reinforcement. Here review of some waste materials, whose ash is used as partial replacement to cement in concrete, is presented. Different properties of fresh and hardened concrete, when admixed with ash of waste materials are reviewed. Concrete containing sugar cane bagasse ash, ground nut shell ash, rice husk ash, saw dust ash, and tobacco waste ash are reviewed. After review, it is observed that further studies are required on all waste ashes replacing cement, which will reveal more potential on their usage in concrete. Concrete containing ash of waste materials attained demanded strength within 5% to 20% replacement.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jawad Ahmad ◽  
Fahid Aslam ◽  
Rebeca Martinez-Garcia ◽  
Jesús de-Prado-Gil ◽  
Shaker M. A. Qaidi ◽  
...  

AbstractIndustrial waste has been rapidly increased day by day because of the fast-growing population which results environmental pollutions. It has been recommended that the disposal of industrial waste would be greatly reduced if it could be incorporated in concrete production. In cement concrete technology, there are many possibilities to use waste materials either as cement replacement or aggregate in concrete production. Two major industrials waste are glass and marble waste. The basic objective of this investigation is to examine the characteristics of concrete waste glass (WG) as binding material in proportions 10%, 20% and 30% by weight of cement. Furthermore, to obtain high strength concrete, waste marble in proportion of 40%, 50% and 60% by weight cement as fine aggregate were used as a filler material to fill the voids between concrete ingredients. Fresh properties were evaluated through slump cone test while mechanical performance was evaluated through compressive strength and split tensile strength which were performed after 7 days, 28 days and 56 days curing. Results show that, workability of concrete decreased with incorporation of waste glass and marble waste. Furthermore, mechanical performance improved considerably up 20% and 50% substitution of waste glass and waste marble respectively. Statistical approach of Response Surface Methodology (RSM) was used optimize both waste materials in concrete. Results indicate better agreement between statistical and experimental results.


2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Musa Adamu ◽  
Bashar S. Mohammed ◽  
Nasir Shafiq

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


2014 ◽  
Vol 548-549 ◽  
pp. 1663-1666
Author(s):  
Fu Xing Wang ◽  
Guo Zhong Li ◽  
Juan Chen

The effect of admixtures on the mechanical properties of recycled fine aggregate cement mortar was studied. The result indicated that compared with blank samples the 28d flexural strength, the compressive strength and osmotic pressure of cement mortar were increased by 15.6%, 35.5%, 41.1% respectively when adding silicone waterproofing agent 0.2wt%, naphdalin series water reducer 1.0wt%, polycarboxylate superplasticizer 0.8wt%. The micro-morphology and hydration products of mortar specimens was observed by SEM, XRD respectively.


2014 ◽  
Vol 803 ◽  
pp. 325-329 ◽  
Author(s):  
Roszilah Hamid ◽  
M.A. Zubir

In this study, recycled glass is used to replace the natural fine aggregate in different mix proportions. The control samples are Grade 30 ordinary Portland cement concrete (OPCC) containing 100% natural sand and coarse aggregate. The recycled glass concretes contain 70% natural fine aggregate + 30% size 300 micron crushed glass (Sample 2), and 70% fine aggregate + 15% size 300 micron crushed glass + 15% size greater than 300 micron crushed glass (Sample 3).The recorded strength of the control, Sample 2 and 3 at 90 days are 47, 61 and 55 MPa. Although the compressive strength for the concrete samples with recycled glass are higher than the control samples, the flexural test results show that, concrete with recycled glass has less ability to be fully functioning as a reinforced concrete by exhibiting their flexural strength at 91 % and 84% of the theoretical flexural strength whereas for the control specimen, its flexural strength is 10% higher than the theoretical value. Nonetheless, the toughness index of recycled glass concrete with 30% replacement of fine sand with recycled glass powder is at par with the control samples, which shows the ductile behavior of the recycled glass concrete.


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