Study On Character Of Rock Wool Waste Cement-based Cementious Materials

As the shortage of resources, global warming and other issues have become more and more prominent, improving building energy saving rate and utilizating resources comprehensively has been treated as an inevitable trend. Rock wool has played an important role in building energy saving. However, there are some by-product after producing rock wool have become a burden to the environment, and a direction for their comprehensive utilization is needed urgently. This paper used experiment method, supplemented by theoretical research methods, analyzed and studied rock wool fibers and furnace bottom slag, which are two components of rock wool waste, aimed at its use in cement-based cementitious material. Some relevant research were did for rock wool waste and the properties rock wool waste used in cement-based cementitious material, including:(1)Chemical composition analysis, mineral composition analysis, thermal analysis, chemical stability analysis and microstructure analysis were did for rock wool fibers and furnace bottom slag respectively. Additionally, the stability analyze of different morphology wastes in alkaline solution draw a conclusion that rock wool fibers is suitable for reinforcement fiber used in cement-based cementitious material directly, while furnace bottom slag is suitable as a mineral admixture added to cement-based cementitious material.(2)Index of strength, volume stability of furnace bottom slag and impermeability, frost resistance, pore structure of furnace bottom slag cement-based cementitious materials were studied. Compared with the performance of fly ash and blast furnace slag cement-based cementitious materials, it is found that furnace bottom slag can be used as mineral admixtures, the influence of strength, impermeability and pore structure of cement-based cementitious materials are between fly ash and blast furnace slag. Furnace bottom slag cement-based cementitious materials also has good frost resistance.(3) Fluidity, compressive strength and flexural bending strength of rock wool fibers cement-based cementitious materials were studied. It had shown that the impact of rock wool fibers to the fluidity of cement-based cementitious materials is less than polypropylene fibers and basalt fiber under the same conditions. Rock wool fibers can increase the compressive and bending strength of cement-based cementitious materials in a proper mixing amount.(4) Uniaxial compression, complete stress-strain curve′s characteristics and elastic modulus of rock wool waste cement-based cementitious materials were studied in double mixing conditions. Based on test results, this paper proposed compression constitutive model of rock wool waste cement-based cementitious materials, combined with damage theory studied the damage constitutive model and evolution curve of rock wool waste cement-based cementitious materials. Experiment results and analysis showed that the amount of rock wool waste can improve the strength and toughness, restrain the development of cracks in a certain extent and improve the deformation ability of cement-based cementitious materials.