A review of recycled aggregate in concrete

May 01, 2018 · Although the researches on recycled aggregate concrete (RAC) has been going on for nearly 70 years , the use of RA in concrete structures is still limited due to its long-term durability concerns. With the decrease of natural aggregate resources and the increase of waste concrete generation, RAC has become a hot research topic around the world.

One such material is recycled aggregate concrete. Utilizing recycled aggregate is certainly an important step towards sustainable development in the concrete industry and management of construction waste. Recycled aggregate is variable properties. Quality of the recycled aggregate depends

May 30, 2018 · The paper reviews the production and utilisation of recycled aggregate in concrete. • Critically analysed the globally published data on recycled aggregate standards. • This review may help to alleviate the concerns of consumers. • This paper can encourage and further promote the use of recycled aggregate.

In this study, recycled aggregate concrete (RAC) with a 0%, 30%, and 50% recycled coarse aggregate substitution rate and a 0% and 15% recycled fine aggregate replacement rate was used as the ...

Mar 29, 2013 · After demolition of old roads and buildings, the removed concrete is often considered worthless and disposed of as demolition waste. By collecting the used concrete and breaking it up, recycled concrete aggregate (RCA) is created (Fig. 1). This paper focuses on coarse RCA which is the coarse aggregate from the original concrete that is created ...

(2013). Use of recycled concrete aggregate in concrete: a review. Journal of Civil Engineering and Management: Vol. 19, No. 6, pp. 796-810.

What is recycled concrete good for?

Recycled Aggregate Concrete (RAC) is concrete that using Recycled Aggregate (RA) as partially or fully replacement in coarse and fine aggregate. It is believed RA have been used from 1945 in concrete producing and started when World War II damaged a large quantity of concrete structures and the high demand of aggregate to rebuild the structures.

mechanical properties for the recycled aggregate concrete. Meanwhile, the alkalinity of recycled aggregate concrete, chloride and sulphate contents of recycled aggregate have not been adversely affected. In the procedure shown in [12], the coarse recycled concrete aggregates were kept immersed in HCl with a molarity of 0.5 mole for 24 h.

The use of recycled concrete aggregate (RCA) in concrete as partial and full replacements of natural coarse aggregate is growing interest in the construction industry, as it reduces the demand for ...

of recycled aggregate in concrete prior to 1996, it was from 1996 until 2002 that the main knowledge base on use of recycled concrete aggregate (RCA) was formed since at that time these materials reflected the highest and most consistent quality of all recycled aggregates available. Mobile crushers whilst often more economical

A literature review of the latest advancements in recycled aggregate concretes with regards to identifying properties, improving performance, and numerical modeling is presented in this paper.

the recycled aggregate concrete is almost 85% and 80% of natural aggregate concrete. Amn on.et.al (2002), concrete having a 28 -day compressive strength of 28 MPa was crushed at ages 1, 3 and 28 days to serve as a source of aggregate for new concrete,

There have been some studies that considered the utilization of recycled concrete aggregate in different construction applications than in production of new concrete. For example, Al-Ali et al. [24, 25] investigated the suitability of using recycled concrete aggregates as subbase for pavement construction. A test model was built in the ...

Jul 07, 2020 · Recycled aggregate concrete is an eco-friendly material that is increasingly being used in new constructions. Nowadays, this application is mainly limited by user’s lack of confidence, as coarse recycled aggregate (CRA) is usually more porous, i.e., it has a higher water absorption, than coarse natural aggregate.

The states that do use recycled concrete aggregate (RCA) in new concrete report that concrete with RCA performs equal to concrete with natural aggregates. Most agencies specify using the material directly in the project that is being reconstructed. Recycling of concrete is a relatively simple process.

recycled aggregate was found useful if the replacement level is about 30% .This type of concrete has been used in many applications. Recycled aggregate can be seen as future material which will be eco -friendly and will decrease in project cost. Keywords: Recycled aggregate, concrete utilizing recycled aggregate, construction and demolition waste.

Purpose: This paper aims to review the effect of using recycled aggregates (RA) on the properties of recycled aggregate concrete (RAC) following the steady rise in global demand for concrete and the large generation of construction and demolition waste.

This paper based on the related recycled concrete aggregate (RCA Recycled Concrete Aggregate) literature, mainly involve its properties, preparation and performance of RCA concrete, construction application etc..This has got a lot of reliable conclusions, so as to give some inspiration and help to the related scholars.

Oct 26, 2020 · Abstract: This study aims to compare the potential environmental impact of the manufacture and production of recycled and by-product aggregates based on a life cycle assessment and to evaluate the environmental impact and cost when they are used as aggregates in concrete.

Based on existing norms and specifications that allow the use of recycled aggregates in the production of concrete, a comparison is made of the parameters involved, such as density, water absorption and contaminants ratio within the recycled aggregates and maximum strength allowed for the recycled aggregate concrete, among others.

The main problem in using recycled concrete aggregate (RCA) as a construction material is due to the weak adhered mortar which usually has higher porosity and water absorption. It also has lower strength compared to natural aggregate (NA), and it often forms weak interfacial transition zones in the recycled aggregate concrete (RAC). These weak ...

The use of recycled concrete aggregate (RCA) as an alternate for dense-graded aggregate base course (DGABC) applications over the recent years have been approximately 10% to 15%.Presently 60 to 70 percent of demolished concrete is using as sub-base course aggregate for road construction.

[14] Yan hongsheng, Experimental study on recycled aggregate concrete sulfate at tack, Concrete, Number 5 in 2013（Total No. 283）, 13-15(In Chinese). [15] An xin zheng, Experiment research on properties of recycled concrete in sulfate environment, Concrete, Number 7 in 2010（Total No. 249）, 31-33 (In Chinese).

Recycled concrete aggregate (RCA) is generally produced by two-stage crushing of demolished concrete, and screening and removal of contaminants such as reinforcement, paper, wood, plastics and gypsum. Concrete made with such recycled concrete aggregate is called recycled aggregate concrete (RAC). The main purpose of this work is to determine

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.

Dec 19, 2019 · listing the potential applications of recycled concrete materials, as highlighted in yellow. Table 1 - Maximum Allowable Percent of Recycled Material. Maximum Allowable Percent (by weight) of Recycled Material. Fine Aggregate for Concrete 9-03.1(2) 0 0 0 0 Coarse Aggregates for Concrete 9-03.1(4) 0 0 0 0

The extensive research on recycled concrete aggregate and recycled aggregate concrete (RAC) as started from year 1945 in various part of the world after second world war, but in a fragmented manner. First effort has been made by Nixon in 1977 who complied all the work on recycled aggregate carried out between 1945-1977 and prepared a state-of ...

This work studies the physical and mechanical properties of recycled concrete aggregate (recycled aggregate from concrete waste) and their influence in structural recycled concrete compressive strength. For said purpose, a database has been developed with the experimental results of 152 works selected from over 250 international eferr ences.

Oct 12, 2016 · The use of recycled concrete aggregate (RCA) is recommended based on a review of literature that investigated the properties and characteristics of RCA, the physical properties of fresh and hardened concrete containing RCA, the mechanical behavior of concrete containing RCA, and special considerations for concrete pavements using RCA to achieve suitable levels of workability, durability, and ...