Abstract: In order to eliminate the error caused by multiple factors on the test results, the effect of different preparation water temperatures on the performance and internal pores of the foamed concrete was studied. The orthogonal test (three factors and three levels) was set, and the optimal water binder ratio is 0.6, the optimal content of fly ash is 15%, and the optimal content of rubber powder is 2%. Seven different water temperatures(15、20、25、30、35、40、45 ℃) were set on above basis, and theeffect of water temperature on the main physical and mechanical properties and internal pore size of foam concrete was studied by collecting the experimental data of compressive strength, dry density, water absorption of foam concrete specimens and micro data of internal morphology. The test results showed that there is a numerical relationship between the compressive strength, dry density, water absorption and water temperature of the foam concrete, and there is a correlation between the physical and mechanical properties. When the foaming water temperature is 30℃ and 35℃, the foamed concrete has the best foaming effect. The number of interconnected pores in the foamed concrete is small, the pore size is uniform, the porosity is high, the average pore size is about 1.9mm, and the physical and mechanical properties meet the requirements of the specification.

Key words: foamed concrete, foaming water temperature, pore size, dry density, compressive strength, factor correlation