scholarly journals Crushing Characteristics of Single Particle of Recycled Aggregate from Waste Concrete

2016 ◽  
Vol 32 (12) ◽  
pp. 23-32
Author(s):  
Sung-Sik Park ◽  
Sang-Jung Kim ◽  
Hong-Duk Moon
Keyword(s):  
Single Particle ◽  
Recycled Aggregate ◽  
Waste Concrete

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.

scholarly journals Study on Properties of Waste Concrete Powder by Thermal Treatment and Application in Mortar

2020 ◽  
Vol 10 (3) ◽  
pp. 998 ◽  
Author(s):  
Yuwu Sui ◽  
Chuping Ou ◽  
Shu Liu ◽  
Jinshuai Zhang ◽  
Qingbo Tian
Keyword(s):  
Particle Size ◽  
Thermal Treatment ◽  
Treatment Process ◽  
Activity Index ◽  
Recycled Aggregate ◽  
Thermal Treatments ◽  
High Quality ◽  
Active Elements ◽  
Waste Concrete ◽  
Mechanical Strengths

Waste concrete must be crushed, screened, and ground in order to produce high-quality recycled aggregate. In this treatment process, 15–30% waste concrete powder (<0.125 mm) can be generated. Hydration activity and the reuse of waste concrete powders (WCPs) were studied in this work, and the results illustrated that the particle size changed after a series of thermal treatments at temperatures from 400 ℃ to 800 ℃. The particle size of waste concrete powder decreased by 700 ℃ thermal treatment, and by 600 ℃ thermal treatment, it increased. More active elements appeared in WCP heated by 800 ℃. Nevertheless, the activity index (AI) of WCP, measured by the ratio of mechanical strengths between mortar with a 30% replacement of the cement with WCP and normal mortar without WCP, indicated that the WCP by 700 ℃ thermal treatment had an optimal AI value, which meant WCP treated at 700 ℃ could be used in mortar or concrete as an admixture.

Experimental Research on Main Properties of New Recycled Coarse Aggregate Concrete

2011 ◽  
Vol 261-263 ◽  
pp. 19-23 ◽  
Author(s):  
Da Xing Qian ◽  
Ying Wei Yun ◽  
Ii Young Jang ◽  
Jong Hoe Kim
Keyword(s):  
Concrete Beam ◽  
Coarse Aggregate ◽  
Economic Benefits ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Secondary Process ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Waste Concrete

Recently reutilization of waste concrete becomes one of the hottest issues in civil engineering field throughout the world. However, most of the concerned research focuses on the RCA (recycled coarse aggregate) by simply crushing waste concrete. In this paper shucking technique is developed to secondary process the simply crushing waste concrete for improving the performance of RCA concrete. Test has been done to demonstrate that performances such as strength, elastic modulus et al. of shucking RCA concrete is better than those of common recycled concrete. Simultaneously, beam specimens are made to test the flexural behavior of shucking RCA concrete. Results showed that the deflection of shucking RCA concrete beam is approximately same with that of natural coarse aggregate concrete beam, which solves current problem that recycled aggregate concrete beam has bigger deflection than common concrete beam. The new shucking technique developed in this paper has many advantages to be applied in practical engineering and it has obvious economic benefits and social effect.

Experimental Study on Recycled Concrete Coarse Aggregate Crushed Index

2014 ◽  
Vol 584-586 ◽  
pp. 1750-1755
Author(s):  
Xiao Lei Chang ◽  
Song Gu ◽  
Zhi Zheng
Keyword(s):  
Coarse Aggregate ◽  
Production Quality ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Waste Concrete ◽  
Concrete Materials ◽  
The Stability ◽  
Index Value ◽  
Different Sources

Compared with natural aggregate, recycled aggregate apparent density, bulk density, porosity, water absorption, large crushing index value, which corresponds to aggregate different sources have different indicators, which largely of recycled concrete limits on the application.. In order to more efficiently improve the utilization of recycled aggregate, ensure the stability production quality of recycled concrete, source unknown and difficult to directly measure its intensity of waste concrete materials, at the time of the preparation of recycled aggregate, it is recommended to repeat loading, using different pressures from different standard strength of recycled concrete coarse aggregate crushed curve to use as a criterion to determine the source of their overall strength. Different in different sources of strength recycled aggregate crushing value mainly reflected on the bond strength.

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.

On Properties of Recycled Coarse Aggregate from Repeatedly Recycling Waste Concrete

2011 ◽  
Vol 368-373 ◽  
pp. 2185-2188
Author(s):  
Ping Hua Zhu ◽  
Xin Jie Wang ◽  
Jin Cai Feng
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Fine Aggregate ◽  
Recycled Coarse Aggregate ◽  
Coarse Aggregates ◽  
Recycled Fine Aggregate ◽  
Waste Concrete

The properties of recycled coarsee aggregates from repeatedly recycling waste concrete were determined. In this study, five series of concrete mixtures using coarse and fine natural aggregates were prepared, which have the same objective slump value from 35mm to 50mm and different compressive strengths ranging from 25MPa to 60 MPa. These five concretes were crushed, sieved, washed with water, hot treatmented at 300°C before they were used as recycled aggregates. After that, recycled aggregate concrete (RAC) was produced with an objectively compressive strength of 30MPa, in which the recycled coarse aggregate was used as 30%, 70% and 90% replacements of natural coarse aggregate and recycled fine aggregate as 10%, 20%, and 30% replacements of natural fine aggregate. After that, these recycled concretes were used as second recycled aggregates to produce RAC with the same objectively compressive strength of 30MPa. The physical properties of coarse aggregates including apparent density, water absorption, attached mortar content and crushing value were tested and their mineral characteristics were analyzed. The results showed that the quality of recycled coarse aggregates from twicely recycling waste concrete reached the requirements from structural concrete.

Crushing characteristics of a recycled aggregate from waste concrete

2018 ◽  
Vol 160 ◽  
pp. 100-105 ◽  
Author(s):  
Sung-Sik Park ◽  
Sang-Jung Kim ◽  
KeQiang Chen ◽  
Young-Jae Lee ◽  
Sae-Byeok Lee
Keyword(s):  
Recycled Aggregate ◽  
Waste Concrete

The High Quality Technical Research of Road Concrete Recycled Coarse Aggregate

2011 ◽  
Vol 346 ◽  
pp. 47-51 ◽  
Author(s):  
M. Mandula ◽  
Xiao Yu Hu ◽  
Feng Jin Chen ◽  
Wen Long Zhang
Keyword(s):  
Coarse Aggregate ◽  
Chemical Characteristic ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Cement Slurry ◽  
High Quality ◽  
Ordinary Concrete ◽  
Recycled Coarse Aggregate ◽  
Waste Concrete ◽  
Physical And Chemical

This paper studies the recycling of solid waste concrete of the foundational content. Through the experimental research on the use of recycled aggregate and recycled concrete powder, I propose recycled coarse aggregate, recycled powder of various physical and chemical characteristic and the powder mixed with cement slurry mixed with recycled coarse aggregate on the surface of the mechanical properties after treatment. The results show that the coarse aggregate crushing value after surface treatment, strength characteristics of concrete can meet the requirements of ordinary concrete.

Evaluation of High Grade Recycled Coarse Aggregate Concrete Quality Using Non-Destructive Testing Technique

2015 ◽  
Vol 776 ◽  
pp. 53-58 ◽  
Author(s):  
Ni Nyoman Kencanawati ◽  
Jauhar Fajrin ◽  
Buan Anshari ◽  
Akmaluddin ◽  
Mitsuhiro Shigeishi
Keyword(s):  
Ultrasonic Wave ◽  
Coarse Aggregate ◽  
Surface Hardness ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
High Grade ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Waste Concrete ◽  
Non Destructive

A large amount of waste concrete generates an environmental problem due to demolition of old concrete structures. To solve this problem, it is necessary to collect recycled aggregate from waste concrete. The conventional recycling technique of recycled aggregate from waste concrete does not indicate a significant quality to be re-used for making a new concrete. We proposed new techniques to produce high grade recycled aggregate by heating-grinding (H-G) method and heating-grinding-acid (H-G-A) method. To ensure the quality of the concrete made from recycled coarse aggregate concrete, the non-destructive evaluation was conducted in this research. High grade recycled aggregate concrete were prepared in advanced using two methods mentioned earlier. Then, new concrete specimens were produced using those types of recycled aggregate concrete. After 28 days curing time, rebound hammer test and ultrasonic pulse velocity test were performed on recycled coarse aggregate concrete to examine the surface hardness and ultrasonic wave velocity of the concrete. Almost similar quality to natural coarse aggregate in terms of density, water absorption, sieve analysis achieved by both H-G recycled coarse aggregate and H-G-A recycled coarse aggregate. However, the surface hardness and ultrasonic wave velocity of H-G-A recycled coarse aggregate concrete is better than those of H-G recycled coarse aggregate concrete. That acid solvent enables to dismantle the cement paste from aggregate surface more effectively, so this types of recycled aggregate shows a better performance than the other one. Continued delamination reduces pores in the interfacial transition zone resulting better bonding mechanism between new cement paste and recycled aggregate surface.

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