Construction and Demolition Waste Utilisation as Recycled Concrete Aggregate in Concrete: A State of Art (original) (raw)
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RECYCLED CONCRETE AGGREGATE (RCA) FOR THE USE IN CONSTRUCTION: GENERAL REVIEW
This paper aims to make a genereal review between the other research due to the topic of Recycled Concrete Aggregate (RCA). In this developing era, the construction plays a big role in creating new environment. In facing this global challenge, the use of Recycled Concrete Aggregate (RCA) to create sustainable construction is the alternative solution to minimize the impact of construction waste. This paper is generally a brief review of the Production, characteristic/mechanical properties, optimization, and application for the RCA. It is then compared to the Natural Concrete Aggregate (NCA). It can be enhanced by some of solution including the mixing to the natural aggregate, admixture, etc. Generally, the quality will be lower but as a part of solution towards the green construction, this result remains good to the point of view. The use of RCA especially gives a big impact in the use of non-structural concrete, even it could be well performed too in the structural matters. Keywords: Recycled Concrete, Aggregate, Demolition, Waste, CDW
RECYCLING OF CONSTRUCTION AND DEMOLITION WASTE FOR SUSTAINABILITY – AN OVERVIEW OF THE USE OF RECYCLED CONCRETE AGGREGATES
Repair, remodeling and reconstruction works are often associated with huge amounts of construction and demolition wastes. The call for sustainable development is answered by the process of recycling this construction and demolition waste (CDW). This paper reviews the potential of materials by recycling CDW, with special reference to concrete waste as aggregates in new concrete. The manufacturing process, processing techniques and their influence on different characteristics of aggregates and thereby the consequent concrete properties associated with non-structural applications are discussed in detail. A case study of the non-structural application of recycled concrete aggregates (RCA) is also mentioned with reference to the above mentioned factors and their influences. It is observed in testing thus far that, no significant underperformance in terms of durability could be observed. Further, its performance in a pervious pavement is under study.
ASSESSMENT OF RECYCLED CONCRETE AGGREGATE (RCA) USAGE IN CONCRETE
Recycling concrete is a significant step towards eco-friendly construction practices. The use of recycled concrete aggregates in new structures provides a sustainable development. Initially, recycling of demolition waste was first carried out after the Second World War in Germany and henceforth, there have been reduction in the quantity of construction and demolition waste; and at the same time, it lessened the depletion of natural resources by providing an alternative. There have been recorded cases of application of recycled aggregate(RA) in a large number of construction projects of many European, American, Russian and Asian countries. The test results of ductility and the stiffness of beams with RA are equal or higher than those with natural aggregate. However, concrete made with recycled concrete aggregates exhibits different engineering properties. This difference is mainly due to the attached mortar paste on recycled concrete particles. Recycled aggregates have been found to have high water absorption capacity, which affects various properties mainly mechanical performance of the resulting concrete mix. Based on previous research, this paper presents a comprehensive overview of the recycled concrete material characteristics and the effect of using recycled concrete material on the mechanical properties, the durability properties and structural performance of concrete so as to help relevant units and staffs in the practical work.
Use of recycled concrete aggregate in concrete: a review
Journal of Civil Engineering and Management, 2013
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 virgin aggregate. In addition, the use of RCA leads to a possible solution to the environmental problem caused by concrete waste and reduces the negative environmental impact of the aggregate extraction from natural resources. This paper presents a comprehensive review on the use of RCA in concrete based on the experimental data available in the published research. The most important physical, mechanical, and chemical properties of RCA are discussed in this paper. However, more emphasis has been given to discuss the effects of RCA on the fresh and hardened properties and durability of concrete. This paper also identifies the gaps existing in the present state of knowledge on RCA and RCA concrete and provides some recommendations for future research.
Using Construction Demolition Waste (CDW) as Recycled Aggregate in Non-Structural Concrete Elements
The main objective of this research is to study the feasibility of using the construction and demolition wastes (CDWs) in the non-structural concrete elements. The tests were carried out in the laboratory by replacing the natural aggregate (NA) with recycled concrete aggregate (RCA) in different percentages 50%, 75% and 100%. The physical properties of RCA were evaluated for crushed and graded concrete rubble gathered from different demolition sites and landfill areas. Measurements of the hardened concrete were carried out for compressive strength and indirect tensile strength. The fresh concrete mixes were tested for slump or workability to ensure the quality of prepared combinations. The total number of casting mixes were 32 samples forming four groups to measure the mechanical characteristics. Groups were divided into four percentages 50%, 75%, 100% RCA and the percent 100% NA which used as a reference sample. The values of the slump were considered acceptable for the RCA up to 50.0%. The results of the tests on the hardened concrete showed that a significant reduction in the mechanical properties of the RCA concrete made of 100% RCA was registered when compared with NA concrete. The properties of RCA concrete made of a blend of 50% NA and 50% RCA showed no significant change in the properties of the hardened concrete. The conclusions of this research have indicated that NA can be replaced with RCA until 50% percent and for the non-structural concrete with strength 25 N/mm 2 .
International Research Journal of Multidisciplinary Technovation, 2019
Solid wastes are the inevitable production of the operations of various industries like construction Industry, Machines Manufacturing Units, Textile industry etc. In India the construction industry generates large amounts of waste, which can be composed of different origin materials, most of them classified as non-hazardous. Construction and Demolition waste (CDW) constitutes a major portion of total solid waste production in the world and most of it is used in landfills. Dumping of these construction and demolition waste in landfill causes contamination of soil, water and air from toxic substances. Research by structural concrete engineers has clearly suggested the possibility of appropriately treating and reusing such waste as aggregates in new concrete. The aim of this paper is to explore the separation process of CDW and further use of recycled aggregates from construction and demolition waste (CDW) in concrete mixes. A review of most recent research and legislation applied in I...
Use of Recycled Concrete Aggregate in Construction: An Overview
– Recycled aggregates have germinated towards a valuable preference for virgin aggregates. RA is created from concrete rubble which has undergone years of services; the resulting RAC carries the weakness of lower density, higher water absorption & higher permeability that limit them to lower grade applications. In order to achieve the best ecology-to-quality ratio considering materials, befitting selections should be made. Concrete mix proportioning is enhanced in order to maximize the usage of C&D waste without the reduction of mechanical & enduringness properties. The experimental follow up were carried out by using detailed strength & durability related tests are explained here for different fusion of recycled aggregates with virgin aggregates. The compressive strength of RAC is found to be higher than the strength of virgin concrete. RAC is in proximity to virgin concrete in terms of split tensile strength, flexural strength and wet density. The slump of RAC is depressed and that can be regenerate by using full substituting of SSD RCA aggregates to the VA. At last it is confirmed that the use of RCA is likely a possible call for structural use. Index Terms-Recycled concrete aggregate (RCA), recycled aggregate (RA), saturated surface dry (SSD), coarse aggregate (CA), virgin (natural) aggregate (VA), C&D.