مقاله انگلیسی رایگان در مورد بررسی چرخه عمر بلوک بتنی با استفاده از مصالح بتن بازیافتی – الزویر 2018

In recent years, the rapid developments of the building industry in China led to a huge quantity of construction and demolition (C & D) waste. On the other hand, a considerable number of nonrenewable natural resources (i.e., limestone and river sand) are depleted every year, resulting in a serious environmental problem. As of today, the rapid growth of the economy in China is at a cost of over-consumption in resources and severe destruction in the environment. In 2015, 3.9 billion tons of C & D wastes were generated in China, while approximately 5% of them were recycled. At the same time, 5 billion tons of natural aggregates were exploited (Fu, 2016). Over the last several decades, there are various solutions used for improving green footprint in concrete industry, such as the addition of Electric Arc Furnace (EAF) slags (Faleschini et al., 2015a, b), textiles (Awal and Mohammad Hosseini, 2016; Zhan and Poon, 2015) and fly ashes (Faleschini et al., 2015c; Alaka and Oyedele, 2016) as well as rubberized concretes (Hesami et al., 2016; Thomas and Chandra Gupta., 2016). In addition, recycling and reusing the waste concrete as recycled aggregates to produce RAC can conserve natural resources and reduce C & D wastes. Therefore, from the viewpoint of sustainable development of concrete, the successful application of RAC is of significant importance (Poon and Lam, 2008; Ling et al., 2013; Shan et al., 2017; Mallick and Radzicki, 2014). Extensive programs have been carried out to study the physical, mechanical and durability properties of RAC in the last two decades (Dilbas, 2014; Zhang et al., 2017; Gao et al., 2012). In 40 comparison with natural aggregates, recycled aggregates have lower strength and higher water absorption ability and are generally weaker, more porous. It is well known that the use of RCAs in RAC will jeopardize the mechanical and durability properties of RAC to a certain extent depending on the quality of the RCAs and the replacement percentage (Kwan et al., 2012; Kou et al., 2011; Gonzalez and Etxeberria, 2014). In addition, the structural performances of RAC elements and structures are a little inferior to those of structures made with conventional concrete. However, through reasonable design and proper mix procedure, RAC elements meet the requirement and can be used in practice as well as some successful applications of RAC in civil engineering have been obtained around the world over the last ten years (Nassar and Soroushian, 2012; Hanif et al., 2017; Mohammed et al., 2014).