Strengths Investigation of Air Entrained Recycled Fine Aggregate Mortar

2012 ◽  
Vol 253-255 ◽  
pp. 432-435
Author(s):  
Jiu Su Li ◽  
Chun Li Qin
Keyword(s):  
Flexural Strength ◽  
Mechanical Performance ◽  
Fine Aggregate ◽  
Aggregate Concrete ◽  
Optimum Dosage ◽  
Recycled Fine Aggregate ◽  
Waste Concrete

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.

Technique Development of Recycling and Utilizing Waste Concrete as Building Material

2012 ◽  
Vol 174-177 ◽  
pp. 275-279
Author(s):  
Da Xing Qian ◽  
Ying Wei Yun ◽  
Il Young Jang ◽  
Woo Young Park
Keyword(s):  
Building Material ◽  
Coarse Aggregate ◽  
Recycled Concrete ◽  
Fine Aggregate ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Recycled Fine Aggregate ◽  
Waste Concrete ◽  
Technique Development ◽  
Recycled Material

In this paper shucking technique is developed to improve the performance of recycled coarse aggregate concrete. Comparison test has been done to demonstrate the good performance of shucking recycled coarse aggregate concrete than that of common recycled concrete. Simultaneously recycled fine aggregate concrete and recycled finely grinded admixture are extracted and studied too. Results show that this new technique can not only improve the performance of recycled material and enlarge recycled material type, but also make waste concrete to be reused completely.

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
Keyword(s):  
Flexural Strength ◽  
Construction Industry ◽  
Carbon Fibers ◽  
Mechanical Performance ◽  
Relevant Literature ◽  
Waste Materials ◽  
Fine Aggregate ◽  
Natural Sand ◽  
The Third ◽  
Recycled Fine Aggregate

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.

Recycling of Waste Concrete and Fly Ash for Recycled Aggregate Concrete: Fundamental Characteristics Evaluation

2009 ◽  
Vol 620-622 ◽  
pp. 255-258 ◽  
Author(s):  
Cheol Woo Park
Keyword(s):  
Fly Ash ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Experimental Program ◽  
Concrete Aggregate ◽  
Fine Aggregate ◽  
Recycled Concrete Aggregate ◽  
Aggregate Concrete ◽  
Waste Concrete

As the amount of waste concrete has been increased and recycling technique advances, this study investigates the applicability of recycled concrete aggregate for concrete structures. In addition fly ash, the industrial by-product, was considered in the concrete mix. Experimental program performed compressive strength and chloride penetration resistance tests with various replacement levels of fine recycled concrete aggregate and fly ash. In most case, the design strength, 40MPa, was obtained. It was known that the replacement of the fine aggregate with fine RCA may have greater influence on the strength development rather than the addition of fly ash. It is recommended that when complete coarse aggregate is replaced with RCA the fine RCA replacement should be less than 60%. The recycled aggregate concrete can achieve sufficient resistance to the chloride ion penetration and the resistance can be more effectively controlled by adding fly ash. It I finally conclude that the recycled concrete aggregate can be successfully used in the construction field and the recycling rate of waste concrete and flay ash should be increased without causing significant engineering problems.

Durability and Mechanical Properties of Self-Compacting Concrete Incorporating Recovered Filler from Hot Mix Asphalt Plants and Recycled Fine Aggregate

2021 ◽  
Vol 894 ◽  
pp. 95-101
Author(s):  
Sepehr Ghafari ◽  
Fereidoon Moghadas Nejad ◽  
Ofelia Corbu
Keyword(s):  
Compressive Strength ◽  
Hot Mix Asphalt ◽  
Mechanical Performance ◽  
Fine Fraction ◽  
Production Plant ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Limestone Filler ◽  
Recycled Fine Aggregate ◽  
Maximum Particle

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.

scholarly journals Effective utilization of recycled fine aggregate powder as reinforcement particles in polyethylene composite

2020 ◽  
pp. 096739112095138
Author(s):  
Yasuyuki Kanda ◽  
Mohammed Abass
Keyword(s):  
Composite Material ◽  
Flexural Modulus ◽  
Homogenization Method ◽  
Fine Aggregate ◽  
Element Analysis ◽  
Polyethylene Composite ◽  
Recycled Fine Aggregate ◽  
Waste Concrete ◽  
Dispersion State ◽  
Concrete Recycling

Effective waste concrete recycling is desirable from the viewpoints of environmental protection and extending the working lives of waste concrete final disposal sites. Recycled fine aggregate powders (RFAP) were obtained by milling waste concrete, and in this paper, we attempted to use RFAP as reinforcement particles in a polyethylene (PE) composite material. The PE powder and RFAP were blended together, and composites were fabricated using compression molding. Our results showed that the flexural strength and flexural modulus of the created composites improved with increased RFAP content. The RFAP dispersion state was honeycomb-like in the composite material, and from inspecting the specimen side view after three-point bending tests, it was apparent that crack propagation proceeded into the RFAP part of the composite, between PE particles. We then performed elastic stress analysis on the composites, in order to define the RFAP reinforcing behavior, using finite element analysis based on the homogenization method. As a result, it was revealed that the Mises stress decreased with increased RFAP content, confirming that there is a potential role for RFAP as reinforcement particles in PE-based composites.

The Properties of Fine Recycled Aggregate Concrete Containing Recycled Bricks from Construction and Demolition Waste

2018 ◽  
Vol 760 ◽  
pp. 193-198 ◽  
Author(s):  
Kristina Fořtová ◽  
Tereza Pavlů
Keyword(s):  
Recycled Aggregate Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Demolition Waste ◽  
Natural Sand ◽  
Aggregate Concrete ◽  
Freeze Thaw ◽  
Recycled Fine Aggregate

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.

On Properties of Recycled Fine Aggregate for Structural Concrete from Repeatedly Recycling Concrete Waste

2014 ◽  
Vol 665 ◽  
pp. 163-166
Author(s):  
Ping Hua Zhu ◽  
Fei Fei Xie ◽  
Qun Xia
Keyword(s):  
Structural Properties ◽  
Experimental Research ◽  
Performance Degradation ◽  
Recycled Aggregate ◽  
Fine Aggregate ◽  
Preparation Process ◽  
Structural Concrete ◽  
Recycled Fine Aggregate ◽  
Waste Concrete

In order to explore the possibility of using repeatedly recycling waste concrete as aggregate to produce structural concrete, experimental research was carried out on the structural properties of three kinds of recycled fine aggregate (RFA) with two-regeneration cycles, two single and one mixed. The results showed that the quality of all RFAs meet the needs of Grade Ⅲ in GB/T25177-2010 and Level L in JISA 5023-2000. The degree of performance degradation is observed to enhance with increasing recycling cycle when taking the same preparation process of recycled aggregate.

Basic Mechanics Characters of Recycled Fine Aggregate Concrete

2012 ◽  
Vol 446-449 ◽  
pp. 2028-2032
Author(s):  
Jian Geng ◽  
Yong Yong Chen ◽  
Jia Ying Sun ◽  
Wei Chen
Keyword(s):  
Fine Aggregate ◽  
Aggregate Concrete ◽  
Recycled Fine Aggregate
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