## 1 Introduction  
The earliest documented references to the use of porous concrete date back to the nineteenth century. In particular, [PERSON] and [PERSON] [1] observed in their literature review that the earliest documented application of porous concrete was in the United Kingdom in the year 1852. At the beginning of the 20 th century, the concept of developing porous concrete, characterized by a significant volume of voids, was first proposed by [PERSON] [2]. Subsequently, the technology of this type of lightweight concrete was studied by many researchers [3, 4, 5, 6, 7, 8, 9]. The production of porous concrete requires the use of both lightweight porous aggregates and conventional heavy aggregates such as gravel or crushed stone. Along with other types of lightweight concrete, porous concrete can be employed as a material for monolithic and prefabricated wall structures, as well as for drainage systems and filters [5, 10]. Porous concrete, also referred as pervious concrete, permeable concrete, or no-fines concrete, is a sandless concrete that is typically produced from a mixture of dense or porous gravel or crushed stone, cement, and water with a limited content of cement paste [7, 11]. The defining characteristic of porous concrete is its distinctive structure, which comprises a greater volume of voids between the grains in comparison to conventional concrete [12, 13]. The applications of porous concrete in various construction fields can be broadly classified into two main areas. The first area encompasses the utilization of porous concrete'sfavorable heat-insulating properties, as evidenced by [4; 14; 15; 16]. The second area pertains to the exploitation of its high permeability, as demonstrated in [7; 9; 17]. This definition, which may appear contradictory at first glance, reflects the specific characteristics of the material's structure, which determine its diverse applications. The density of porous concrete with normal-weight aggregate usually is typically limited to 1800 kg/m\({}^{3}\), which makes it effective for products and structures requiring enhanced strength at a relatively low density [10; 18]. Due to its high water-passing capability, porous concrete is employed in pavement applications that facilitate the direct passage of water from precipitation and other sources, thereby reducing runoff from a site and fostering groundwater recharge [7; 19; 20]. One of the areas of application for porous concrete is in the construction of wall structures. To date, there has been some experience gained in the construction of such structures with porous concrete. Additionally, porous concrete has been employed for the insulation of brick walls and in conjunction with other materials to construct two- or three-layer enclosing structures [3; 21]. Additionally, there is evidence in the literature of the construction of monolithic walls made of porous concrete, particularly for low-rise buildings [3; 5; 10]. The design of porous concrete compositions can be realized in any way, provided that a material with the specified strength, frost resistance, and density is obtained from a mixture that has the required workability with minimum cement consumption [9; 22]. The grain size of aggregates for porous concrete is usually in the range of 5 to 40 mm. The use of more homogeneous aggregates increases the void content and reduces the density and thermal conductivity of the concrete. It also has a positive effect on lower cement consumption [5; 7; 23]. The consumption of cement, aggregate, and water determines the test mixes used to produce the control cubic specimens. At the same time, the selected composition should not result in the porous concrete mix stratification. A concrete mix with a correctly selected composition is characterized by [17; 24; 25; 26; 27; 28]:  
* A homogeneity and uniform coating of aggregate grains with cement paste;
* An absence of cement paste trickling from aggregate grains during concrete pouring;
* The absence of the stratification of the concrete mix during transport and pouring.