| Nowadays,environmental protection has become one of the most thorny social issues.As a kind of common solid waste,steel slag’s output accounts for about 15%to 20%of crude steel production,while the comprehensive utilization rate is less than10%.The accumulation of steel slag not only occupies a large amount of land,but also causes serious pollution,therefore,it is imminent to realize large-scale comprehensive utilization of steel slag.At present,recycling utilization of steel slag in building materials is one of the major approaches for the comprehensive utilization of steel slag.Among of them,the researches on preparation of foamed concrete insulation materials with steel slag have been quite extensive,but most of researches still focus on the material itself and ignore the impact of the service environment on its performance.Therefore,in this project,the thermal performance test of steel slag foamed concrete was carried out from two scales of materials and models,and the influence of environmental temperature and humidity on the thermal insulation performance of slag foamed concrete was discussed based on the periodic temperature and humidity environment to be simulated the natural environment.The main research work and results are as follows:(1)Basic performance test of steel slag foamed concrete was carried out.The test results show that:the dry bulk density of steel slag foamed concrete was concentrated in 1000kg/m~3;the water absorption rate was between 30%~35%;the compressive strength was about 10MPa on 28d;the thermal conductivity was about0.21W/(m·K).(2)The test on thermal conductivity of steel slag foamed concrete under different temperature and humidity was carried out.The test results show that:with the increase of water content,the thermal conductivity of steel slag foamed concrete didn’t increase along a line and the increasing trended to be lower and lower;the thermal conductivity of steel slag foamed concrete increased with the increase of temperature,and there was a good linear-relationship between them;the thermal conductivity of steel slag foamed concrete increased with the cycle of periodic temperature and humidity,and the increasing trended to gentle.(3)Steel slag foamed concrete room models were set up and then were put into the temperature and humidity alternating humidity test chamber to be suffered periodic temperature and humidity,at the same time,the temperature and humidity inside the models were monitored,what’s more,the effect of periodic temperature and humidity on the thermal insulation performance of steel slag foamed concrete wall materials was studied with difference of temperature and humidity as the evaluation index,the test results show that:as the temperature and humidity of the environment fluctuated wildly,the temperature inside the room models also responded accordingly.Among of them,the change of ordinary concrete was the most intense,foamed concrete was the gentlest,and steel slag foamed concrete was between the two,so the thermal insulation performance of steel slag foamed concrete was slightly worse than foamed concrete but far superior to ordinary concrete.As the temperature and humidity of the environment fluctuated wildly,the humidity in the room models also changed.The change of the ordinary concrete was the most intense,the foamed concrete was the gentlest,and steel slag foamed concrete was slightly lower than ordinary concrete,so the moisture transfer performance of the steel slag foamed concrete was slightly poor.For steel slag foamed concrete,the condensation phenomenon was unavoidable because of the strong water absorption of steel slag,the solutions to the condensation of steel slag foamed concrete wall were put forward in this paper.(4)Solid modeling analysis of steel slag foamed concrete external insulation system was conducted by ANSYS software,the results showed that the insulation performance of steel slag foamed concrete was much better than that of ordinary concrete. |
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