## 1 Introduction  
Concern about the environment and sustainability has driven industries to research and rethink more sustainable methods with a view to minimizing impacts. For example, geopolymeric materials, which can be considered a cementitious material, have been developed with the purpose of replacing Portland cement and, consequently, reducing the environmental impacts caused by the cement industry through a decrease in energy consumption and CO\({}_{2}\) emissions [1, 2]. Another way to minimize environmental impacts (generating excessive waste, littering public roads and streets because of irregular disposal and depleting natural resources) and achieve sustainability is to increase the use of construction civil waste (CCW) in the development of materials for civil construction. This has not yet been widely applied. For example, in Brazil, only, approximately 20% of CCW is reused [3, 4, 5]. From the perspective of sustainability, using this type of waste can reduce both the consumption of raw materials (for example, small and large aggregates) and the consumption of energy spent on extraction/comminution/finishing processes [6]. However, using these recycled aggregates in concrete and mortar can be hampered by the limitations imposed by the composition of CCWs, since recycled materials present high water absorption, lower specific mass, and lower mechanical resistance when compared to materials (concretes, adhered or bonded mortar) developed only with natural aggregates [7; 8; 9]. Therefore, using recycled aggregates becomes more attractive in cases where high mechanical resistance and low water absorption are not required. In addition, studies have shown that this type of aggregate obtained from CCW does not result in good durability when exposed to aggressive media [3; 10]. A construction material that does not require a structural function is so-called \"aerated\" or \"cellular\" concrete, the apparent specific mass of which ranges from 320 kg/m\({}^{3}\) to 1920 kg/m\({}^{3}\)[11]. Cellular concretes can be obtained by introducing air bubbles into the mixture. Air bubbles may be generated in the mortar itself by chemical additives or by introducing preformed foam into the mortar. The aerated concretes prepared by incorporating the preformed foam into the mortar are known as foamed concrete (FC) [12]. Also, there are types of lightweight structural concretes that are obtained by totally or partially replacing conventional aggregates with lightweight aggregates, which have an apparent specific mass of between 900 kg/m\({}^{3}\) and 2000 kg/m\({}^{3}\)[13; 14]. FCs present excellent performance in terms of thermal and acoustic insulation and fire resistance. For example, the study by [PERSON] et al. [15] evaluated the thermal performance of FCs developed with different additives (fly ash, lime, and polypropylene fiber) and densities, and found thermal conductivity values between 0.18 W/mK and 0.56 W/mK. [PERSON] and [PERSON] [16] analyzed the acoustic qualities of three types of aerated concrete (gas cement concrete; gas cement concrete with combined binder-Portland cement and lime; and foam cement concrete) and showed that the acoustic absorption coefficient values of normal materials depend on permeability and porosity and increase the coefficient of sound absorption by up to 0.6. [PERSON] and [PERSON] [17] evaluated the thermal conductivity at high temperatures of FCs with different densities in order to obtain data on material properties to predict fire resistance and concluded that FCs may be an alternative that can replace gypsum in partition walls. In spite of the positive properties of FC, due to the lack of the compressive strength of this type of material, its use becomes limited, which points to a need for studies on optimizing the mixtures that seek to improve this property of the material [18; 19]. However, it should be noted that there is no Brazilian standard for foamed concrete.