Production, characterization and investigation of thermal energy regulation properties of foam concretes with diatomite/capric acid composite

Phase change materials (PCM) can store or release energy depending on the ambient temperature. Therefore, the use of PCM in building materials is of great importance in terms of increasing the energy efficiency and improving the thermal comfort of buildings. In this thesis, diatomite, which has a porous form, was used as support material and subjected to direct impregnation with capric acid (CA). As a result of the applied leakage tests, it was determined that diatomite could absorb CA at most 50% by weight. The prepared diatomite/KA composite was included in foam concrete mixture as a sand substitute at four different ratios of 15%, 20%, 25% and 30% by weight. According to thermal analysis results, melting and freezing temperature; melting and freezing enthalpy values of diatomite/KA composite were determined as 28.73 ˚C ve 28.49 ˚C ile 101 J/g ve 193 J/g, respectively. Depending on increase in amount of diatomite/CA, water absorption and apparent porosity values increased, while the spreading diameter and dry unit weight values decreased. Thermal conductivity and compressive strength values decreased depending on the increase in amount of diatomite/CA. For foam concrete with 30% diatomite/CA, the highest water absorption, apparent porosity and compressive strength values were measured as 25.9%, 34% and 6.31 MPa, respectively. Thermal conductivity values varied in the range of 0.495-0.241 W/mK. Thermoregulation test results show that foam concrete slabs with 30% diatomite/CA composite provide a significant reduction (cooling) in surface and ambient temperatures and can contribute to the reduction of heating at night.