A Review of the Durability of Recycle Aggregate Concrete

2015 ◽  
Vol 744-746 ◽  
pp. 1357-1360 ◽  
Author(s):  
Hong Bo Liu ◽  
Jing Sun ◽  
Xiao Hong Cong

Analyzing the related literature at home and abroad, this paper summarized the results and shared them with reasearchers involved in the field on the recycled aggregate concrete (RAC). In this paper, the durability of RAC will be described from the following several aspects: absorption, chloride permeability, freezing and thawing resistance, carbonation, the sulfate corrosion resistance, drying shrinkage, creep and abrasion resistance. This paper expounded the present situation and progress in the study of the durability of recycled aggregate concrete.Then, some key technical problems needed to be studied were pointed out and many suggestions were put forward.

2019 ◽  
Vol 9 (9) ◽  
pp. 1935 ◽  
Author(s):  
Jung-Ho Kim ◽  
Jong-Hyun Sung ◽  
Chan-Soo Jeon ◽  
Sae-Hyun Lee ◽  
Han-Soo Kim

In recent years, the amount of construction waste and recycled aggregate has been increasing every year in Korea. However, as the recycled aggregate is poor quality, it is not used for concrete, and the Korean government has strengthened the quality standards for recycled aggregate for concrete. In this study, research was conducted on the mechanical and durability characteristics of concrete using recycled aggregate, after developing equipment to improve the quality of recycled aggregate to increase the use of recycled aggregate for environmental improvements. The results illustrated improvements in the air volume, slump, compressive strength, freezing and thawing resistance, and drying shrinkage. Furthermore, this study is expected to contribute to the increased use of recycled aggregate in the future.


Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 843
Author(s):  
Yuji Miyazaki ◽  
Takeshi Watanabe ◽  
Yuji Yamada ◽  
Chikanori Hashimoto

Since high quality natural aggregates are becoming scarce, it is important that industrial recycled products and by-products are used as aggregates for concrete. In Japan, the use of recycled aggregate (RG) is encouraged. Since, strength and durability of recycled aggregate concrete is lower than that of normal aggregate concrete, the use of recycled aggregate has not been significant. In order to improve physical properties of concrete using recycled coarse aggregate, blast furnace slag sand has been proposed. Recently, blast furnace slag sand is expected to improve durability, freezing, and thawing damage of concrete in Japan. Properties of fresh and hardened concrete bleeding, compressive strength, and resistance to freezing and thawing which are caused by the rapid freezing and thawing test using liquid nitrogen is a high loader than the JIS A 1148 A method that were investigated. As a result, concrete using treated low-class recycled coarse aggregate and 50% or 30% replacement of crushed sand with blast furnace slag sand showed the best results, in terms of bleeding, resistance to freezing and thawing.


2013 ◽  
Vol 567 ◽  
pp. 119-122
Author(s):  
Yue Qin Tang

This paper addresses problems of aggregate concrete of construction wastes, which were featured as large water absorption, quick slump loss, as well as easy bleeding and low strength of concrete. A comparative analysis by experiment between recycled aggregate concrete and ordinary concrete was made on aspects of water absorbability, compressive strength, slump loss, bleeding rate, drying shrinkage and economic efficiency. It has found possible to preparing the recycled aggregate concrete of high performance through the prewetting recycled aggregate. It is concluded that construction wastes can be recycled by obtaining the optimum mole of preparing recycled aggregate concrete of construction wastes and evaluating their reliability on cost-lefficiency and mechanic capability,thus, it also recycled the limited resources and solve some environment problems.


2013 ◽  
Vol 7 (1) ◽  
pp. 232-236
Author(s):  
Yuanchen Guo ◽  
Xue Wang ◽  
Jueshi Qian

Material adsorption, the reverse process of evaporation diffusion, directly reflects the wettability of materials. Wettability is one of the main factors that affect the drying shrinkage of materials. A device that measures the wettability of recycled aggregate concrete (RAC) with fly ash is proposed in this study based on pore structure theory. The isothermal absorption curve of RAC is examined with different fly ash contents. Results show that as the recycled aggregate replacement rate increases, the moisture absorption capacity of RAC gradually increases. The addition of fly ash improves the porosity of RAC structures and reduces material wettability.


2011 ◽  
Vol 335-336 ◽  
pp. 1223-1226
Author(s):  
Yuan Chen Guo ◽  
Xue Wang

Material adsorption process is the reverse process of evaporation diffusion, reflecting directly the wetting degree of material, is one of the main factors of material drying shrinkage. Based on pore structure theory, this article designed a device measuring the wetting properties of materials, tested different recycled aggregate replacement rate recycled aggregate concrete isothermal absorption curve. The article proposes the water contact angle can be calculated from the initial absorption curve, and analyzes its impact on drying shrinkage of recycled aggregate concrete.


2008 ◽  
Vol 400-402 ◽  
pp. 447-452 ◽  
Author(s):  
Hong Bing Zhu ◽  
Xiu Li

Recycling old concrete as an alternative source for production new concrete can solve the environment produced by old concrete. To make such recycling feasible, the strength and durability of the recycled aggregate concrete (RAC) must be assured. Prepared recycled coarse and fine aggregate using natural concrete specimens produced by compressive strength test of cubic concrete. Prepared recycled aggregate concrete which replacement ratios is 50% and 70%. Processed compressive strength test of cubic RAC specimens. Carried through the test for resistance of concrete to rapid freezing and thawing on both RAC and natural concrete. As a result of the experiment, the strength of the RAC can reach the design strength, however, the index for the resistance of concrete to rapid freezing and thawing depressed to a certainty degree relative to that of common concrete. Replacement ratio of aggregate influenced relative dynamic modulus of elasticity of RAC seriously. The weight change increased as long as the number of freezing and thawing cycles increased, and the weight change increased when replacement ratio elevation. RAC showed a sharp weight loss during the testing period, and reduce the water cement ratio can increase the durability characteristics of RAC. Also, absorption of the recycled aggregate influenced durability properties of RAC badly.


Sign in / Sign up

Export Citation Format

Share Document