Mechanical Properties of Perlite Concrete in Context to Its Use in Buildings' External Walls

Nowadays, much of the attention paid to building construction is focused on sustainability and environmental protection. The materials applied in construction should be safe and free of toxins, but they should also follow the idea of circular construction. Quests for materials with an appropriate structure and composition, unifying features of a construction, insulation (thermally and acoustically), and environmentally friendly material turned our attention in this paper toward expanded perlite (EP). This study aimed to analyze the results of the experimental determination of the basic physical and mechanical parameters of expanded perlite and pure perlite concrete blocks (PPC), i.e., containing 100% EP instead of sand, while in contrast, most existing studies focus only on the partial replacement of sand with EP. This research aims to confirm that PPC containing 100% EP is the product that meets the requirements for load-bearing walls in single-family buildings in European countries such as Poland. The study aimed to determine the procedure for preparing the samples of PPC, i.e., the mixing procedure, the displacement speed during compaction, and the maximum loading force during compaction. It was determined that the appropriate speed of compaction to form the samples is 15 mm per minute, i.e., the same as during the compressive strength tests. The maximum compaction force of 10,000 N during the preparation of samples at a speed of displacement of 15 mm per minute guarantees a compressive strength greater than 3 MPa for dry density class 650, and the method of forming the samples in a single layer, i.e., solid samples.