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Using environmental product declarations to support pavement green public procurement
Published in John Harvey, Imad L. Al-Qadi, Hasan Ozer, Gerardo Flintsch, Pavement, Roadway, and Bridge Life Cycle Assessment 2020, 2020
M. Rangelov, H. Dylla, N. Sivaneswaran
PCR for construction aggregates was issued in 2016 under the American Society of Testing and Materials (ASTM) as a program operator (ASTM International 2017). The category of construction aggregates encompasses sand, gravel, crushed stone, crushed concrete, iron slag, steel slag, or any combination thereof. Interested parties involved in PCR development were producers and suppliers of construction materials (aggregates, primarily), industry associations, and academia.
Reuse of mining waste into innovative alkali-activated-based materials for road pavement applications
Published in Sandra Erkens, Xueyan Liu, Kumar Anupam, Yiqiu Tan, Functional Pavement Design, 2016
Cesare Sangiorgi, Claudio Lantieri, Piergiorgio Tataranni, Joao Castro-Gomes, Marco Gabriel
In the area of road construction aggregates, from medium to coarse size, are essential for the production of workable loose materials that, when compacted, form the bearing skeleton of pavement layers and foundations. Nevertheless, added value should be given to the artificial aggregates to overcome the production and marketing costs, especially when used in rich layers such as the bituminous ones.
Utilization of Laterite Waste in Concrete
Published in Karra Ram Chandar, B. C. Gayana, P. Shubhananda Rao, Mine Waste Utilization, 2022
B. Manjunath, Karra Ram Chandar
In general, concrete is a mixture of cement, fine aggregate, coarse aggregate and water. In order to utilize waste produced from different sources in concrete, laterite waste was used in place of fine aggregate, and GGBS from steel and iron industry waste was used to replace cement partially. The details of the respective materials used for the specimen preparation are discussed in the sections below.Cement: Cement is a binder substance that sets and hardens and can bind other materials together. Cement used in construction can be characterized as being either hydraulic or non-hydraulic in nature, depending upon the ability of the cement to be used in the presence of water. The most important uses of cement is as a component in the production of mortar in masonry and in concrete as combination of cement and as an aggregate to form a strong building material. Ordinary Portland cement is the most common type of cement generally used around the world. Locally available 43 grade cement of ACC brand is used for experimental purpose. The physical properties of cement are given in Table 4.1.Aggregates: Construction aggregate, or simply aggregate, is a broad category of coarse particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates are the most mined materials in the world. The aggregate serves as reinforcement to add strength to the overall composite material. These aggregates are mainly classified into two types, namely, fine aggregate of size less than 4.75 mm and coarse aggregate of size more than 4.75 mm. Locally available river sand is used as fine aggregate. Gravels constitute major part of coarse aggregates. The sample of coarse aggregates in a pan is shown in Figure 4.2. The physical properties of aggregates are given in Table 4.2.Laterite soil: Laterite is well known in Asian countries as a building material for more than 1000 years (Schellmann et al. 1994). Laterites are the products of intensive and long-lasting tropical rock weathering which is intensified by high rainfall and elevated temperatures. These soils are rich in iron and aluminium and are rusty red in colour due to the presence of iron oxides (Schellmann et al. 1994). Figure 4.3 shows sample of laterite soil in a pan.Ground-Granulated Blast-furnace Slag (GGBS): GGBS is waste product obtained from Iron ore industries. GGBS is obtained by quenching molten iron slag (a by-product of iron and steel-making) from blast furnace in water or steam to produce a glassy granular product that is then dried and ground into a fine powder (Siddique and Kaur 2012). This powder is added to concrete to improve the strength properties of concrete and hence called admixture. The specific gravity of GGBS used for the experimental purpose is 2.9.
Design for deconstruction using a circular economy approach: barriers and strategies for improvement
Published in Production Planning & Control, 2020
Olugbenga Akinade, Lukumon Oyedele, Ahmed Oyedele, Juan Manuel Davila Delgado, Muhammad Bilal, Lukman Akanbi, Anuoluwapo Ajayi, Hakeem Owolabi
Deconstruction is a building end-of-life scenario that allows the recovery of building components for building relocation, component reuse, recycling or remanufacture (Kibert 2008). Although the recovered material may be utilised for reuse, recycling or remanufacturing, the focus of deconstruction is material reuse. One could argue that the recycling and remanufacturing of building components is now common practice. However, a more beneficial and challenging task is the ability to relocate a building or reuse its components without reprocessing (Akinade et al. 2015). This is because building relocation and components reuse require minimal energy compared to recycling and remanufacturing. Figure 1 shows how deconstruction enables a closed material loop and circular economy conditions at the end of life of buildings. Reuse is a process where salvaged building components are used ‘as-is’ without any repair or upgrade (Nordby et al. 2009). Reuse is the most preferred end-of-life scenario because it requires no energy input compared to remanufacturing and reuse. Examples of building materials that could be reclaimed “as-is” and reused include brick, blocks, tiles and building components (doors, windows, radiators, etc.). Remanufacturing is the process of restoring salvaged materials to “like-new” condition. Remanufacturing sometimes require repair and replacement of damaged bit of the salvaged items to make them fit for usage. The process of remanufacturing usually requires intensive manual labour to isolate damages, repair and restore the item. Recycling is the process of converting salvaged materials into raw materials into the manufacturing of other building materials. Even so, recycling also includes the conversion of salvaged materials into aggregates and additives. Georgakellos (2006) argues that the process of transforming salvaged materials into raw materials could be criticised because its environmental impact could exceed the environmental benefits. However, a recycling process that requires less energy for processing and production will be more plausible to justify the adoption of recycling (Blengini 2009). Example of recycling would be the use of rubbles as construction aggregate that is used as infilling materials and recycling reinforcement steel bars.