Geopolymer concrete (GPC) is obtained by activating industrial wastes such as fly ash with chemical liquids such as sodium hydroxide (NaOH) and sodium silicate (Na2 SiO3). In order to use environmentally friendly GPC obtained from industrial wastes instead of portland cement concrete (OPC), its behavior in structural elements is important and should be investigated in detail. Load-displacement characteristics, flexural and shear stiffnesses and crack development of samples were obtained by numerical analysis. The GPC beams to be an alternative to OPC beams, their mechanical properties and fracture modes must be at least as much as OPC. As a result of the analyses, it was determined that the 110x20x15 cm GPC beams with compression reinforcements of 2Φ8 and tension reinforcements of 2Φ8, 3Φ14 and 2Φ18, respectively, showed similar flexural, shear and crack development with OPC beams. Simulations of GPC beams were made up to the breaking point, contributing to the understanding of its behavior.

One of the important areas of Phase Changing Materials (PCM) is to increase the heat retention capacity of building components. Researches are carried out on the heat retention capacities of PCMs to store energy in building components and to ensure building temperature control. The use of PCM in building components has become an important tool for energy saving, since ensuring building temperature control in summer and winter conditions is a situation that requires continuity. This feature provided to the building component provides an improvement in the energy identity of the building. In general researches, the use of macro, micro encapsulated PCM decreases the heat conduction coefficient as it increases the heat retention capacity of the building components, but effects compressive strength positive or negative. However, when the capsule size used in micro capsule applications is reduced to 7 microns and below, it is seen that the strength increases, while the thermal conductivity coefficient continues to decrease. When the PCM capsule particle sizes used in the building components are reduced, it provides an improvement in the granulometry of the component, so a positive effect on strength is seen in the building components. As a result of this research, differences in compressive strength were observed depending on the macro, micro and nano dimensions and mixing ratios of the pcm addition. However, due to the continuous increase in the PCM ratio of the building component, the heat holding capacity of the building component increases and its thermal conductivity decreases.