As an alternative to natural aggregates, steel slag aggregate (SSA) has been investigated widely and has shown good performance and benefits in concrete applications. ... The ISC process generates little dust pollution, has a high degree of automation, and reduces the risk of steam explosion as it lays a thin steel slag layer …
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Aggregate production methods can be classified under the following three categories: Obtaining natural aggregates from quarries (the first scenario). Obtaining …
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V.L.S. Gschwenter et al. [61] concluded that a jigging process allows to produce recycled aggregates, containing more than 99.5 % mass of concrete, with adequate properties to replace natural aggregate in new concrete production. Also, the results indicated the possibility of recovering more than 75 % of the original concrete in …
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A literature review comprising 163 publications published over a period of 26 years from 1992 to 2018 is presented in this paper. This review discusses the generation and recycling of construction and …
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Lightweight aggregate (LWA) is defined as solid substance with an apparent density of less than 2.0 g/cm 3 and a bulk density of less than 1.2 g/cm 3 1.LWAs are porous and often granular materials ...
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Aggregates are raw materials that are produced from natural sources and extracted from pits and quarries, including gravel, crushed stone, and sand. When used with a binding medium, like water, cement, …
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Crushing is one of the most energy-consuming technological processes. The purpose of grinding is to achieve the desired grain size of mineral raw materials. The process of grinding consists of many factors, for example, the size and form of crushed grains, as well as their mutual arrangement inside the crushing machine chamber, the …
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This article reviews the geological aspects of aggregates, their production, consumption, and environmental impacts. It covers the main types, sources, and modes …
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1. Introduction. The construction sector is responsible for approximately 6 billion tons of CO 2 emissions [1].Furthermore, the demand for raw material as aggregate for concrete is around 2.7 billion tons/year in EU countries altogether [2], 900 million tons/year in the USA [3], and 700 million tons/year in Brazil [4].Besides, at the end of the …
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supplement natural aggregate would also be beneficial because it will minimise depletion of natural resources such as limestone and sand. The continuous exploitation of these natural resources can result in environmental problems or high project costs (Hainin et al., 2012; Ziari & Khabiri, 2007). Due
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Recycled concrete aggregates get less than with natural aggregate density. According to a study by Limbachiya et al, the relative density of recycled concrete aggregate (saturated surface in the dry state) is about 7-9% lower than natural aggregate. 2. Recycled Concrete Aggregate Vs Natural Aggregate: Porosity and Water Absorption
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The components were determined based on the qualitative composition of the components (presented in Table 1) and available literature on recycled lightweight aggregates.The silicon and aluminum oxides present in the components were the basis for forming lightweight ceramics, glass as a flux to lower the melting point, and tailings …
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There are two main categories of aggregates used in construction: natural aggregates and manufactured aggregates. Let's take a closer look at each type and explore their characteristics and applications. Natural Aggregates. Natural aggregates are sourced from naturally occurring materials such as rocks, gravel beds, and riverbeds.
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The first step in the process of creating natural aggregate is identifying the perfect place to blast for the required stone. Once the right place in the quarry has …
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The aggregate fraction was composed of three types of crushed limestone aggregates of different granulometric sizes and coarse and fine natural siliceous sand. The average compressive strength of SC at 28 days was 46.2 MPa.
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The extraction process of natural aggregates included crushing and screening. In the case of limestone ("Limestone, crushed, for mill {GLO} (GLOBAL)"), the infrastructure data in Ecoinvent were estimated based on a normalized infrastructure with an annual production capacity of about 145,000 tonnes of product per year, which is …
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Its particle shape was quite different from that of natural aggregates. For example, the shape of natural aggregates is rounder and less sharp. The recycled coarse aggregate (RCA) contains fewer needle flakes than natural aggregates. This is mainly affected by the collision, peeling during the crushing process and the location of the …
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Utilization of recycled concrete aggregates (RCA) as a replacement for natural aggregates in innovative concrete has gained fame around the world as a way to decrease natural aggregate use. ... Gokceb A, Saekic T, Hisada M (2004) Assessment of recycling process induced damage sensitivity of recycled concrete aggregates. Cem …
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The purpose for which aggregates are sampled impacts the process and care required when sampling aggregates. The purpose for obtaining samples also establishes the procedure, frequency and size of the sample required. Aggregate samples might be obtained for source evaluation or aggregate production control,
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What are aggregates? Aggregates are raw materials that are produced from natural sources and extracted from pits and quarries, including gravel, crushed stone, and sand. When used with a binding medium, like water, cement, and asphalt, they are used to form compound materials, such as asphalt concrete and Portland cement concrete.
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Obtaining natural aggregates from quarries (the first scenario). ... As shown by Fig. 4, the recycling process of the aggregates is considered for the next computations based on a Chinese proposal plan (a 200-ton/h plant proposed by Zhengzhou Machinery Co., Ltd). Fig. 4. Scheme of the aggregates recycling process for the …
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cement to produce concrete or mortar. Aggregates may be natural such as gravels and sands and may also be product from crushed rocks as in quarries. The absence of natural aggregate at cost effective transportation distances has prompted extensive use of manufactured aggregates. The US aggregate industry produces 1.1
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The NA consisted of crushed natural aggregate obtained from a local quarry, while the RCA was obtained from concrete cylinders crushed with an ad hoc machine (see Figure 5). The crushed material was sieved to obtain aggregates that passed through a 20 mm sieve and was retained on a 4.75 mm sieve.
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The objective of this study was to evaluate and compare the environmental impacts of obtaining natural aggregate and recycled aggregate, taking Spain as a case study. ... Technology of the process ...
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Procedures for obtaining aggregate samples from project sites for quality tests. Aggregate Sampling, Testing, and Quality Assurance 33 and porosity to also report the testing procedures, for example, ASTM, AASHTO, or agency- developed specification. The number of agencies at each category for individual tests are summarized in Table 3-3.
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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 waste (C&DW) and other wastes, such as ceramic, polyethylene terephthalate (PET), glass, and slag. Furthermore, around 32 bi tons of natural aggregate (NA) are extracted …
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1. Introduction. In the pursuit of sustainable development in construction industry, there is a pressing need to find alternative aggregates for the production of concrete since approximately three-quarters volume of concrete is occupied by aggregates (Behera et al., 2014), and especially when the extraction of natural aggregates has …
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A. Arun proposed that recycled coarse aggregate (RCA) will be an ideal option to reduce the amount of concrete waste going into landfills since coarse aggregate accounts for a major volume of concrete [6]. However, the quality of RA from construction and demolition waste may not be as good as that of natural aggregate (NA).
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This chapter explains the origin, classification, and properties of natural aggregates for concrete, derived from igneous, sedimentary, and metamorphic rocks. It also covers the …
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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 concrete …
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