Study On The Temperature And Humidity Response Law Of Bulk Concrete With Artificial Temperature Compensation

In order to ensure the long-term safe operation of the whole life cycle of the dam,the time has entered the stage of intelligent construction.In the process of construction and service,the cracking of concrete dam caused by temperature stress is one of the important reasons to threaten its safety.Whenever,concrete dam has been under the influence of the temperature of the external environment.inside and outside of the concrete temperature gradient is always cyclically changing,.After adopting traditional way to pouring temperature gradient control temperature in construction period,there is no effective means can run in a subsequent period to continue to control the temperature of the concrete,not active at other times compensation according to the change of environmental temperature on concrete temperature adjustment.Especially when the concrete structure is in an area with harsh environment and a large temperature change,it is more important to carry on the continuous temperature compensation and moisture preservation measures for concrete.In the present,the way to control concrete temperature can not initiativly and chronically adjust the temperature of dam when the environment temperature is changing.So seeking a new method,which can reduce concrete temperature gradient and adjust temperature stress,will be greatly and practical significance.Based on the experiment,it has got the following conclusions:(1)To the bulk concrete,the heat exchange rate of concrete and the external environment can be effectively reduced by covering the insulation layer on the surface;Through the pipeline water temperature for temperature control,the concrete surface covering the area of the thermal insulation layer and their internal response was found to be inversely associated with the heat source temperature rise time,positively correlated with the internal temperature rise rate,therefore increase the thermal insulation of concrete surface area covered,can improve efficiency of the temperature rise of concrete.Through the pipe cooling,temperature control,water temperature,concrete surface covering the area of the thermal insulation layer with internal heat source temperature rise time there was a positive correlation between response and positively correlated with the internal temperature drop rate.(2)When the heat preservation measures are complete,the temperature of the heat source increases linearly in the temperature rise and control,except that the temperature in the other parts of the concrete is increased linearly.In the regulation of temperature drop,the cooling water temperature drops linearly,and the temperature of other parts of the concrete is reduced by the "convex parabola".For the same specimen,the temperature change rate of different parts of concrete in the same horizontal interface has a quadratic function relationship with the vertical distance to the heat source surface.(3)For bulk concrete,the humidity diffusion driven by temperature gradient effect obviously,change the temperature of the concrete can effectively to drive the humidity,the performance of concrete temperature gradient,the greater the driving effect of humidity,the better,and manifests through the concrete cover insulation can make concrete effect on driven by temperature variation of humidity is more sensitive.(4)When the temperature control pipe is used to adjust the concrete,the farther the distance from the heat source is,the less the response is.Compared with the effective temperature control range,the effective temperature control range of concrete is smaller than that of the pipe in the same position.