_Article_  
**Characterization and Use of Construction and**  
**Demolition Waste from South of Brazil in the**  
**Production of Foamed Concrete Blocks**  
**[PERSON] 1, [PERSON] 2, [PERSON] 2,**  
**[PERSON] 1 and [PERSON] 1,***  
Footnote 21: foot  
and demolition comprise the most significant part of all potentially recyclable residues, and in some cases, such as the Netherlands and Denmark, the reuse of the produced CDW can be up to 80% [5]. In the United States, approximately 136 million tons of waste were generated by construction and demolition activities, of which only about 28% were recycled [6]. However, recently in China, only less than 10% of CDW was recycled, while the majority of the waste remained to be simply landfilled or just dumped [7]. CDW from Brazil represents more than 40% of solid urban residues [8]. In many medium (population from 100,000 to 500,000 inhabitants) and large size (population higher than 500,000 inhabitants) Brazilian cities, CDW residues are produced by activities such as renovation and demolition (60%), and new buildings (20%) and house (20%) construction [9]. In Passo Fundo, the CDW produced comes from renovation and demolition (42.5%), the cleaning of urban lots (16.7%), the construction of buildings (11.1%) and houses (18.6%), and from soil excavation (11.1%) [10]. The irregular and clandestine dumping of these residues is a problem that generates significant environmental impacts such as degrading roads and public places, the uncontrolled generation of residues, the silting up of waterways, unpleasant odors, burning, noise, and the depletion of natural resources, among others [11]. Aside from the environmental impacts, discarding these residues occupies spaces that could be used for housing, since the Passo Fundo region has a significant deficit of land for such purpose [12]. On the other hand, this material presents positive reuse potential, whenever it is properly separated and transformed into new feedstock [13]. In Brazil, CDW is mainly composed of bricks, ceramics, ceramic blocks, concrete and mortar, wood and wood boards, plaster, and metallic materials, among other materials [14; 15]. The Brazilian legislation classifies CDWs into four classes: A, B, C, and D. Class A contains the reusable or recyclable residues produced by construction, demolition, renovation, paving repairs, and other infrastructure works, as well as from the construction and/or demolition of precast concrete objects such as ceramic (bricks, blocks, tiles, floor boards, etc. ); mortar and concrete; and even soil derived from earthwork. Class B contains residues such as plastics, paper, cardboard, metals, glass, and wood, among others. Residues for which there are still no developed reuse technologies or applications are included in Class C; for example, residues derived from products that use plaster in their composition. Class D includes hazardous residues derived from fabrication processes such as paint, solvents, oils, etc., or those contaminated or harmful to health arising from demolition, renovations, and repair in radiological clinics and industrial facilities; it also includes roofing tiles, and other objects and materials containing asbestos or products harmful to human health [15]. In Brazil, CDW constituents are included predominantly in Class A--around 91% of mass--and Class B, (9%). The CDW constituents in Classes C and D have not been quantified [14]. In Passo Fundo, according to [PERSON] et al. [10], 94.5% of CDW constituents are included in Class A, 3.1% in Class B, 2.4% in Class C, while Class D did not contain significant amounts. According to [PERSON] et al. [16], four main kinds of construction and demolition wastes have reuse potential as recycled aggregate such as concrete, mortar, ceramic materials, and road residues.