Research On Temperature Gradient Limit And Remote Monitoring Technology Of Mass Concrete Construction

Mass concrete structure is widely applied to the main stress parts of civil engineering structures.The cracks caused by the runaway temperature of mass concrete will affect the bearing capacity and durability of the structure.It is not only difficult to repair the cracks later,but also causes great economic losses.In the construction of mass concrete,the temperature of concrete is increased by the heat released by the hydration reaction,the temperature of the concrete surface is reduced because of the influence of the atmosphere temperature.The temperature gradient and temperature gradient inside and outside the concrete are too large.When the temperature stress caused by the concrete exceeds the present tensile ability of the concrete,the concrete surface will crack.The process of concrete cracking is not completed instantaneously,and temperature stress leads to concrete cracks,which is the result of temperature change at a time.And how to prevent the cracks from controlling the temperature gradient of mass concrete is a major difficulty in practical engineering.At present,the common method of monitoring the construction temperature of mass concrete is to bury the heat sensor in the concrete of the mass concrete pouring site.The monitoring personnel measure the pre buried measurement point,record the measured data,analyze the internal data,and draw the conclusion of temperature change,thus guide the construction and maintenance of the concrete.Because there are many different parts of the mass concrete structure,the monitoring points are also more scattered,the temperature measurement work is large and complex,so the temperature monitoring value is poor,the manual reading data error is large,the monitoring is difficult under the bad weather condition,the monitoring frequency is limited and can not deal with the data and feedback in time,and the influence of the monitoring personnel quality,resulting in the temperature measurement is not good.Some big problems,such as timely and inaccurate,often occur.This method of temperature monitoring is no longer able to meet the needs of modern mass concrete temperature monitoring.In this paper,according to the temperature monitoring of the construction stage of the large volume concrete of the pile foundation,the floor and the floor steel beam of acertain square basement,it is found that the cracking of the concrete is related to the temperature difference and the temperature gradient of the concrete at the actual age.The temperature gradient corresponding to the temperature gradient over the present tensile capacity of the concrete will lead to the concrete.Crack。 In the construction stage of mass concrete,there is a correlation between the temperature difference and the temperature gradient of concrete and the distance between the concrete and the inside and outside of the concrete.The important technical methods to reduce the temperature stress by controlling the temperature gradient and prevent the development of the harmful cracks are put forward.ANSYS finite element software is used to analyze the temperature and stress variation of large volume concrete with different sizes.During the construction process,the change of temperature gradient affects the development process of the cracks.According to the comparison with the actual monitoring data,the maximum temperature gradient allowable for different depth of the concrete at different ages is studied and the construction of the mass concrete is discussed.The influence mechanism of technology on its cracks is to lay a theoretical foundation for controlling its temperature cracks.In view of the shortage of existing monitoring technology,combined with the demand of actual engineering environment,an intelligent remote monitoring system composed of remote monitoring technology and monitoring instrument is developed by integrating various technologies of Internet and automation.The internal and external temperature of large volume concrete is collected by wireless transmission,and the remote data processing is completed,so that the monitoring personnel can be remotely operated through mobile phones and computers.Login,if the technology is applied to practical engineering,it can provide guarantee for the smooth operation of mass concrete temperature control operation.