## 1 Introduction  
Lightweight concrete (LWC) is one of the types of concrete that receives the most attention. Research studies typically focus on its production technologies and the use of porous aggregate [1]. The variety of porous aggregates is very large. Depending on the intended use, LWC can be used for load transfer with the lowest possible density or as thermal insulation, in the form of floor-to-ceiling walls [2]. [PERSON] et al. [3] investigated the sound absorption of LWC and found that these materials are also useful for effective practical applications in indoor and outdoor environments. Lightweight aggregate (LWA) concrete is widely used in special projects or structures because it is lightweight, frost resistant, crack resistant, seismic resistant, and has energy dissipation and energy absorption properties [4]. In recent decades, expanded glass (EG) has been used as LWA. LWC made using EG as LWA, which is comparatively much lighter than conventional LWA, might lead to different performance in lightweight reinforced concrete elements [5]. [PERSON] et al. [6] stated that EG has been used in construction as a lightweight non-structural and semi-structural material. Due to the low density of the EG aggregate, the compressive strength of this material is relatively low [7, 8]. EG is a fine, porous building material with porosity of 85-90%. Its density may vary from 187 to 1600 kg/m\({}^{3}\)[9] and it is clean, light, flame resistant, efficient, environmentally friendly, and easy to handle. Despite the low density of the material, it has sufficient strength to be used in building constructions (0.45-0.55 N/mm\({}^{2}\)), having low water absorption, and high resistance to chemicals and frost action [10, 11, 12, 13, 14]. As described in [15], as the EG aggregate content increases, the density value drops from 2328 kg/m\({}^{3}\) (for the control mix) to 1401 kg/m\({}^{3}\), for concrete with 100% EG aggregate, and the compressive strength value drops from 30.67 to 14.97 MPa. To further lighten the LWC, polystyrene foam beads can be used. LWC made with polystyrene foam beads reduces thermal conductivity and water absorption [1]. [PERSON] [16] studied a composite material made of polystyrene foam waste, Portland cement, and various additives. The density of the obtained material ranged from 150-350 kg/m\({}^{3}\). The author found that the compressive strength of such a composite material was low (0.05-0.42 MPa) but reducing the density and compressive strength allowed a low thermal conductivity coefficient to be obtained, ranging from 0.0493-0.0955 W/(mK). [PERSON] et al. [17] performed tests on cellular concrete specimens using polystyrene foam pellets. They found that replacing sand with polystyrene foam beads in cellular concrete reduced compressive strength by 47.2%. The authors used 1.54-1.65 kg of polystyrene foam beads per 1 m\({}^{3}\) of cellular concrete. EG and expanded polystyrene (EP) aggregate are a lightweight potential replacement for thermal insulating LWC, because there are large amounts of glass and EP waste in the world, which can be used as a secondary, and environmentally friendly, raw material [18]. Several authors have emphasised that materials containing light aggregate are less resistant to frost but have sufficient frost resistance to be used in wall constructions [19; 20; 21]. The frost resistance of LWC especially decreases when the amount of LWA and the size of the aggregates themselves increase [22]. [PERSON] et al. [23] noted that the freezing resistance of LWC is mainly determined by the porosity of the product. [PERSON] et al. [24] indicated that a concrete's resistance to freezing is not only determined by the system of air gaps in the product, but also by the connections between the aggregate and the matrix.