Limestone in cement could be a source of CO3^2- needed for thaumasite formation which will result in thanmasite form of sulfate attack （TSA） probably. TSA has more deterioration than ettringite or gypsum form of sul...Limestone in cement could be a source of CO3^2- needed for thaumasite formation which will result in thanmasite form of sulfate attack （TSA） probably. TSA has more deterioration than ettringite or gypsum form of sulfate attack because it targets the calcium silicate hydrates （C-S-H） which is the main binder phase in all Portland cement-based materials. By means of physical and mechanical property testing as well as erosion phases analysis, magnesium sulfate attack of cement-based material containing 35% limestone powder by mass at 5 ± 2 ℃ is investigated. The compressive strength and flexural strength of mortar specimen immersed in MgSO4 solution increase firstly, then decrease rapidly with the immersing age. Relative dynamic elastic modulus of mortar specimen changes in a phased process. After immersing in MgSO4 solution for 15 weeks, the main erosion phases in paste specimen change from four phases compounds, three phases compounds to two phases compounds from surface to inside. Deterioration course of limestone cement-based material exposed to magnesium sulfate aggressive environment appears progressive damage layer by layer, and every layer probably suffers four stages, which are property strengthening stage, initial degradation stage, thaumasite formation stage and cementation loss stage, respectively.展开更多
In the development process of the society nowadays,electrical engineering has been widely used with remarkable results,but there are still some problems in the course of actual management,which requires effective tech...In the development process of the society nowadays,electrical engineering has been widely used with remarkable results,but there are still some problems in the course of actual management,which requires effective technical measures to control the quality in electrical engineering and the enhancement of safety management work.Therefore,in order to better ensure safety management requirements in electrical engineering and strengthen related trainings and thus better carried out safety management and quality control to meet respective requirements in the real world,in this paper,a brief analysis is conducted in quality control and safety management in electrical engineering.展开更多
To apply automation in electrical engineering is to use a series of devices with functions of automatic detection and control to realize the realtime or remote control,management,and monitoring of the original electri...To apply automation in electrical engineering is to use a series of devices with functions of automatic detection and control to realize the realtime or remote control,management,and monitoring of the original electrical system.Therefore,the electrical automation technology has broad development space in the construction of electrical engineering,and it is worth of application and study for relevant electrical installation engineering and scientific research departments.In the actual production process,it is necessary to optimize the production mode,reduce the cost,and keep the good working performance of electrical equipment.Based on this,this article briefly analyzes the application of electrical automation in electrical engineering,hoping to provide an effective reference.展开更多
基金Funded by the National Natural Science Foundation of China(No.51109073)
文摘Limestone in cement could be a source of CO3^2- needed for thaumasite formation which will result in thanmasite form of sulfate attack （TSA） probably. TSA has more deterioration than ettringite or gypsum form of sulfate attack because it targets the calcium silicate hydrates （C-S-H） which is the main binder phase in all Portland cement-based materials. By means of physical and mechanical property testing as well as erosion phases analysis, magnesium sulfate attack of cement-based material containing 35% limestone powder by mass at 5 ± 2 ℃ is investigated. The compressive strength and flexural strength of mortar specimen immersed in MgSO4 solution increase firstly, then decrease rapidly with the immersing age. Relative dynamic elastic modulus of mortar specimen changes in a phased process. After immersing in MgSO4 solution for 15 weeks, the main erosion phases in paste specimen change from four phases compounds, three phases compounds to two phases compounds from surface to inside. Deterioration course of limestone cement-based material exposed to magnesium sulfate aggressive environment appears progressive damage layer by layer, and every layer probably suffers four stages, which are property strengthening stage, initial degradation stage, thaumasite formation stage and cementation loss stage, respectively.
文摘In the development process of the society nowadays,electrical engineering has been widely used with remarkable results,but there are still some problems in the course of actual management,which requires effective technical measures to control the quality in electrical engineering and the enhancement of safety management work.Therefore,in order to better ensure safety management requirements in electrical engineering and strengthen related trainings and thus better carried out safety management and quality control to meet respective requirements in the real world,in this paper,a brief analysis is conducted in quality control and safety management in electrical engineering.
文摘To apply automation in electrical engineering is to use a series of devices with functions of automatic detection and control to realize the realtime or remote control,management,and monitoring of the original electrical system.Therefore,the electrical automation technology has broad development space in the construction of electrical engineering,and it is worth of application and study for relevant electrical installation engineering and scientific research departments.In the actual production process,it is necessary to optimize the production mode,reduce the cost,and keep the good working performance of electrical equipment.Based on this,this article briefly analyzes the application of electrical automation in electrical engineering,hoping to provide an effective reference.
