The contents and release behavior of heavy metals in construction and demolition waste used in freeway construction

2019 ◽  
Vol 27 (1) ◽  
pp. 1078-1086
Author(s):  
Yuyun Chen ◽  
Yiqiang Zhou
2015 ◽  
Vol 768 ◽  
pp. 333-339 ◽  
Author(s):  
Sheng Huang ◽  
Xiao Feng Gao ◽  
Tian Xie ◽  
Yan Qiu Sun ◽  
You Cai Zhao

Distribution of hazardous substances and their release potential were investigated in industrial construction and demolition waste (ICDW) of several chemical and metallurgical factories. Results showed that inorganic matters like heavy metals, organic matters like pyrethroids exist as a result of industrial pollution, which might pose a potentially serious threat to the nearby surroundings while abandoned. In this study, wash-off coupled with ultrasonic process, immobilization and natural degradation experiments were performed on the simulated ICDW on basis of different pollutants. Up to 65% of Cl was reduced through ultrasonic wave pretreatment. Addition of CaO and construction & demolition waste(C&D) powder inhibited the mobilization of heavy metals with rainfall tremendously, among which Cr and Cu, in particular, was cut by 80-100% in aqueous. Compared with being stacked and abandoned inside the workshop, heat and direct sunlight largely accelerated the degradation of pyrethroids. This study provides a new insight into strategies to the ICDW management, and the achievement of source pollution control as well.


2020 ◽  
Vol 12 (5) ◽  
pp. 2055 ◽  
Author(s):  
Gianluca Bianchini ◽  
Igor Ristovski ◽  
Igor Milcov ◽  
Alojz Zupac ◽  
Claudio Natali ◽  
...  

In the Republic of Macedonia, construction and demolition (C&D) waste is often dumped, underestimating the potential recycling and re-use as raw materials for civil engineering works and/or cement/ceramic industries. SAMCODE (Sustainable Approach to Managing Construction and Demolition Waste) is a know-how exchange program, the focus of which is chemical characterisation in terms of major and trace elements in order to evaluate the possible Macedonian C&D waste recycling. Thirty-nine C&D waste samples were collected from different dumps in Skopje and surroundings. X-ray fluorescence analyses, carried out on powdered samples, show i) highly variable concentrations, indicative of the heterogenous nature of C&D waste, and ii) high concentration in Cr, Ni, and Zn with respect to Italian, Chinese, and Dutch tolerance limits, probably due to the presence of these elements in ophiolitic rocks and sulphide-bearing deposits, used as raw material in building activity. Inductively coupled plasma mass spectrometry analyses of leachates, performed to assess the mobility of heavy metals, show significant concentrations of Cr, and to a lesser extent, Ni. Results suggest that homogenisation processes of the recycled materials should be implemented and preliminary screening of C&D waste should be performed to eliminate heavy metals-bearing components.


2019 ◽  
Author(s):  
A.P.K.D. Mendis ◽  
◽  
A. Samaraweera ◽  
D.M.G.B.T. Kumarasiri ◽  
D. Rajini ◽  
...  

2020 ◽  
Vol 6 (9) ◽  
pp. 73169-73180
Author(s):  
Kelly Patrícia Torres Vieira Brasileiro ◽  
Bacus de Oliveira Nahime ◽  
Michell Macedo Alves ◽  
Pâmela Millena Kunan ◽  
Vitor Alvares ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2247
Author(s):  
Fernando da Silva Souza ◽  
José Maria Franco de Carvalho ◽  
Gabriela Grotti Silveira ◽  
Vitória Cordeiro Araújo ◽  
Ricardo André Fiorotti Peixoto

The lack of usable aggregates for civil construction in Rio Branco (capital of Acre, a Federal State in the Amazon region) makes the production and use of recycled aggregates from construction and demolition waste (CDW) an alternative of great interest. In this study, a comprehensive characterization of CDW collected from 24 construction sites of six building types and three different construction phases (structures, masonry, and finishing) was carried out. The fine and coarse recycled aggregates were produced and evaluated in 10 different compositions. The aggregates’ performance was evaluated in four mixtures designed for laying and coating mortars with a total replacement of conventional aggregates and a mixture designed for a C25 concrete with 50% and 100% replacement of conventional aggregates. CDW mortars showed lower densities and greater water retention, initial adhesion, and mechanical strength than conventional mortars. CDW concretes presented lower densities and greater resistance to chloride penetration than conventional concrete, with a small mechanical strength reduction. The recycled CDW aggregates proved to be technologically feasible for safe application in mortars and concrete; for this reason, it is believed that the alternative and proposed methodology is of great interest to the Amazonian construction industry, considering the high costs of raw materials and the need for defining and consolidating a sustainable development model for the Amazon region.


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