Effect of functional fillers on the thermal insulation performance of polyurea/fluorocarbon-based concrete protective panel materials

Aiming at the shortcomings of traditional polyurea protective coatings in weather resistance and thermal insulation performance when face slab concrete in plateau regions is under fatigue action caused by intense ultraviolet radiation and large temperature variations, this paper uses polyurea/fluorocarbon as the base fluid and investigates the effects of two functional fillers — flaky aluminum powder and hollow glass microspheres — on the thermal insulation property of protective materials. The results demonstrate that the base fluid achieves optimal comprehensive performance at a polyurea-to-fluorocarbon mass ratio of 6∶4. The optimum single dosages of flaky aluminum powder and hollow glass microspheres were 10% and 15%, respectively. The protective material fabricated with the optimal compound doping formula (10% aluminum powder + 15% hollow glass microspheres) significantly narrows the internal-external temperature difference of concrete. The temperature difference drops from 19.4℃ in the scenario without protective material coating to 12.2℃, marking a reduction of 37.1%, which effectively mitigates the accumulation risk of temperature stress damage. Flaky aluminum powder is arranged in parallel in the coating to form a reflective layer, and hollow glass microspheres are evenly dispersed to form a barrier layer, which are complementary in space. The combined use of the two fillers delivers a "reflection-barrier" synergistic thermal insulation effect. This composite has promising application prospects in plateau environments featuring strong UV radiation and drastic temperature fluctuations.