| Steel slag is the main by-product of the iron and steel metallurgy industry,currently about 70% of the steel slag is in the state of piling and landfill, causing the dispute with farming land, environmental pollution and ecological destruction. Steel slag contains the basic properties of strength, hardness and activity of building materials, in recent years, research on resource utilization of steel slag in concrete has gradually increased, but there still exist several problems, such as large emissions but low utilization, and consumption of secondary energy utilization, etc., the implementation of large amount and low-power resource utilization of steel slag has important research value and practical significance. In terms of thermal insulation material, research and application of foamed concrete has been quite widely, but its own structural defects which leading to low strength, poor stability of slurry and higher water absorption limit its further application. Therefore, based on the resource utilization of slag in the wall material, the steel slag material was prepared as aggregate steel slag foamed concrete, and focus on its thermal insulation properties, to provide new ways and theoretical support with large scale and low energy consumption and efficient resource utilization of slag in building materials.Around the study of steel slag foamed concrete preparation and its insulation properties, this paper carried out research on steel slag foamed concrete preparation,basic performance and insulation properties. By orthogonal experiment, this paper mainly research the influence laws of steel slag content, particle size and dosage of foaming agent to mechanical properties and thermal properties of steel slag foamed concrete. The results showed that: the performance and dosage of foaming agent have the most dramatic effect on dry bulk density, water absorption, compressive strength and thermal conductivity of steel slag foam concrete; compared with the particle size of steel slag, steel slag content has greater impact on concrete performances; with the increase of steel slag content, the compressive strength, dry density, water absorption and thermal conductivity increase. The dry density of prepared steel slag foamed concrete test specimen is between concrete and ordinary concrete. With the dry density of concrete increases, the compressive strength and water absorption rapidly decrease, and the thermal conductivity rapidly increases, and the maximum of thermal conductivity slightly bigger than pure cement matrix. In short, mechanical properties and thermal properties of steel slag foamed concrete is between concrete and foamed concrete properties, the thermal storage performance performed than ordinaryconcrete.On the basis of experimental research, we carried out the theoretical analysis and research on heat preservation performance and its mechanism of steel slag foamed concrete. First of all, we get the calculation formula of dry bulk density and compressive strength of steel slag foamed concrete through the multivariate nonlinear fitting. Secondly, according to the test results, we deduce the three phase coefficient of thermal conductivity model, and then verified and corrected it, the adjusted coefficient of thermal conductivity model is close to the test results. Correction parameters is not the only sure, it remains to be further revised. Finally, by using the MATLAB software to establish a two-dimensional random aggregate model, and the finite element software ANSYS to simulate the internal transient heat transfer process of steel slag foamed concrete, and then analyze the heat conduction rules between steel slag, bubble and slurry. |
