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aggregate production controls and testing procedures are the same so that the aggregate characteristics declared by different producers are directly ... A recycled aggregate having 55% concrete, 25% brick, 19% asphalt and ≤1% clay would have the categories Rc50, Rb30-, Ra20- and X1-.
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For the former, it has been estimated an electricity consumption of 1.74 kWh per tonne of recycled aggregate produced; 0.38 l of diesel is used to produce 1 t of secondary raw material. Finally, 0.03 kg of steel is used in the production of 1 t of recycled aggregate from a fixed plant.
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The production of recycled coarse aggregate implies generating large amounts of fines – a minimum fraction of 35–40%. As Fig. 2 shows, the generation of fines increases with a reduction in porosity of the recycled coarse aggregate, which is an increase in quality. Some recycling processes generate water absorptions around 1% …
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This paper investigates the use of carbon-conditioned recycled aggregate (RA CO2) in concrete production.Experimental work is conducted for RA CO2 with varying chamber pressure (0 kPa, 75 kPa, 150 kPa), chamber duration (0 min, 30 min, 90 min) and RA CO2 replacement percentages (0%, 30%, ) for concrete production. Average …
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ons for processing general waste.Asphalt recyclingReusing fossil bitumen as well as aggregates in recycled. sphalt makes sense financially and environmentally. The …
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Construction and demolition activities consume large amounts of natural resources, generating 4.5 bi tons of solid waste/year, called construction and demolition …
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The figure shows that the production of fine aggregate from crushed stone has a single score environmental impact equivalent to 11.89 mPt (about 17% for extraction and handling, 23% for processing and 60% for transporting from extraction sites to the utilization sites), whereas 7.88 mPt is recorded from river sand (about 40% for extraction …
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Case Study 1: The first case study considers a cradle-to-gate LCA to quantify the GWP in terms of CO 2 equivalent (CO 2-e) emissions associated with the manufacture of 1 m 3 concrete containing blended OPC and SCM binders and natural and recycled aggregate (Fig. 1).In this analysis, emissions arising from cement production, …
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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. To this end, the six potential environmental impacts (i.e., abiotic …
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Carbon-conditioning or chemical permeation methods can provide excellent microstructural improvements to recycled concrete and brick aggregate; however, the applications have their limitations. Further, recycled brick aggregate cannot be effectively carbon-conditioned with conventional methods as it contains only trace amounts of …
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A comparative analysis of the experimental results of the properties of fresh and hardened concrete with different replacement ratios of natural with recycled coarse aggregate is presented in the paper. Recycled aggregate was made by crushing the waste concrete of laboratory test cubes and precast concrete columns. Three types of …
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The recycled aggregate obtained from demolished ... Milled waste glass was used as secondary cementitious material towards production of recycled aggregate concrete with improved strength and ...
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Recycled aggregate used to produce concrete differs from natural aggregate in t hat it contains old mortar attached to the surface of the aggregate. The RCA recycling process
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ASTM C1602 – Mixing Water Used in the Production of Hydraulic Cement Concrete; ASTM D558 / AASHTO T 134 – Moisture-Density (Unit Weight) Relations of Soil-Cement Mixtures ... ICFs systems has the potential to contain recycled materials, such as recycled aggregate (from crushed concrete) and recycled polystyrene.
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In this study, natural aggregates, recycled aggregates (RAs), and carbonated RAs were combined to prepare concrete. Strength, drying shrinkage, microstructures, and the carbon emissions of concrete prepared with different aggregate combinations were explored and compared.The results show that the compressive strengths of carbonated …
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Part II. Structural behaviour of recycled aggregate concrete and engineering applications. Resour Conserv Recycl 53:107–112. Article Google Scholar Liu S, Shen P, Xuan D, Li L, Sojobi A, Zhan B, Poon CS (2021) A comparison of liquid-solid and gas-solid accelerated carbonation for enhancement of recycled concrete aggregate.
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Recycled aggregate is a sustainable solution for environmental depletion of construction sector. ... This article presents a literature review on the production and utilization of recycled aggregate in concrete. Because of its higher water absorption and lower density, the use of recycled aggregate can cause a slight reduction in workability ...
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The best estimates for 2015, of total aggregate production and recycled aggregate production of European Union countries including Ireland and the United Kingdom are depicted in Fig. 3 while Table 2 shows values for 6 years from 2010 to 2015. In European Union, the processing of construction waste (concrete, brick, asphalt and stone) into ...
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Electric arc furnace (EAF) slag is a by-product of steel production in electric arc furnaces. Several studies have tried to demonstrate its suitability in civil engineering application, such as in bituminous mixtures and cement-based materials, due to its good physical, chemical and mineralogical properties. Particularly the re-use as coarse …
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It is a good way to use recycled aggregate produced by waste concrete to replace natural aggregate to prepare Recycled Aggregate Concrete (RAC), which improves the recycling rate of CDW and reduces the pressure of over-exploitation of natural resources. ... Research on RAC production plays a pivotal role in Chinese …
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Blengini et al. propose a management approach, i.e. sustainable aggregates resource management project (SARMa), which proposed guidelines for the sustainable management of aggregates.As per diversified studies conducted in recycling CDW, recycled concrete aggregate (RCA) can replace a significant portion of NA in the …
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In addition, methods for enhancing the mechanical characteristics of recycled aggregate and long-term efficiency such as improving the properties without modifying the recycled aggregate (namely, different concrete mixing designs and the addition of reinforcing fibers) were reviewed. ... Journal of Cleaner Production. Elsevier; …
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A field study of recycled aggregate concrete in structural and non-structural element. • Compressive strength and rebound hammer correlation of recycled aggregate concrete. • Long term (up to 5 years) in-situ performance of recycled aggregate concrete. • The long-term strength of recycled aggregate concrete was comparable to conventional ...
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In addition, the crushing in the recycled aggregate production process further develops cracks in the pores of the recycled aggregates. These cracks eventually result in a large number of weak structural planes in the recycled aggregates and a significant reduction in the particle strength. The pores and cracks of the recycled …
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Fig. 10 shows concrete containing natural coarse aggregate and recycled brick coarse aggregate (Liu et al., 2021). Hence, the RCA's physical, chemical, and mechanical characteristics must be investigated before use (Mills-Beale and You, 2010). As previously discussed, it is important to note that these properties would differ from the …
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Recycled aggregate concrete2.1. Recycled aggregate. Recycled aggregates include coarse recycled aggregates (CRA) with a typical particle size range of 4.75–31.5 mm and fine recycled aggregates (FRA) between 0.16 and 4.75 mm [27]. Since RA obtained from CDW contains hardened cement paste or mortar and the surface of …
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Recycled aggregates (RAs) have been playing an important role in replacing natural aggregates (NAs) in concrete production, thereby contributing to a reduction in the extraction of natural resources and the promotion of a circular economy. However, it is important to assess the global impacts of this replacement, in both environmental and …
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Recycled Aggregate Types Recycled Type 1 (Sub-Base) Type 1 recycled aggregate is a type of recycled construction material that is produced from crushed concrete and sometimes includes other materials such as brick, asphalt, or rock. It is often used as a sub-base material for road construction, pathways, and hard-standing areas.
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Reuse of recycled aggregate in the production of alkali-activated concrete. P. Chindaprasirt, T. Cao, in Handbook of Alkali-Activated Cements, Mortars and Concretes, 2015 19.2 A brief discussion on recycled aggregates. Recycled aggregate is defined as aggregate resulting from the processing of inorganic or mineral material previously used …
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Martinez-Arguelles G., Acosta M. P., Dugarte M., Fuentes L. Life Cycle Assessment of Natural and Recycled Concrete Aggregate Production for Road Pavements Applications in the Northern Region of Colombia: Case Study. Transportation Research Record: Journal of the Transportation Research Board, 2019. 2673: 397–406.
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