Thermal and strength properties of lightweight concretes with the addition of aerogel particles

The aim of this work was to examine the influence of the addition of aerogel particles on the properties of cement composites manufactured using fly ash aggregate. The composites were tested at three different concentrations of water saturation of the coarse aggregate. Moreover, two methods of aerogel particle application were used – plasticising the mix with superplasticiser and aerating with an air-entraining admixture. An assessment of the thermal properties was made during the first 28 d of curing of the composites and compressive strength tests were conducted after 7 and 28 d. For pore structure characterisation, mercury pore structure analysis was carried out on the pure aerogel, the cement composites and the composites with the addition of granulate. The data obtained indicate that adding aerogel particles to concrete composites is an appropriate method of improving thermal parameters: thermal conductivity coefficients were two times smaller compared with control samples without aerogel and, simultaneously, the volumetric specific heat was comparable to that of the control samples. However, the addition of aerogel resulted in a reduction in compressive strength to approximately only 30% of that of the control samples.