Research On Temperature Effect Of Hydration Heat Of Mass Concrete Of Bridge Structure Cap

In the process of pouring and forming large-volume concrete,the hydration heat reaction will cause the temperature difference between inside and outside to change rapidly,causing micro-defects in the interior or surface of the concrete.Will cause cracking and affect the normal use of the structure.Therefore,it is of great significance to study the reasonable selection of temperature control parameters and the development law of temperature damage caused by concrete hydration heat.Therefore,on the basis of summarizing the previous research results,this paper studies the selection of temperature control parameters of mass concrete and the temperature damage caused by hydration heat,relying on the construction of the main pier cap of a bridge.The main research are as follows:1.In the analysis of temperature control of large-volume bearing platform,the adjustable parameters are often determined based on experience,and the construction cannot be guided according to local conditions.For this problem,the adjustable parameters are proposed as temperature control technical indicators,and their research on concrete hydration heat and cooling pipes is studied.Based on this,the determination principle and the parameter selection range under the principle are given,and the applicability analysis of the principle and parameter selection is carried out.The research results show that the parameters determined according to this principle can be used to guide the preliminary analysis of temperature control of mass concrete.2.Relying on the construction of the main pier platform of the project,the influence of seasonal construction on the temperature field distribution of mass concrete is analyzed.The results show that the measured temperature values are in good agreement with the finite element simulation results.The surface temperature of the concrete is greatly affected by the ambient temperature.The performance during winter construction is more obvious.The internal temperature is basically unaffected and temperature peak affect long time.3.Based on the hydration heat analysis and damage calculation of the construction methods used for mass concrete,the effects of different construction methods such as layered pouring and water cooling on the concrete strain field and damage field are obtained.The results show that the amount of concrete temperature damage has a positive correlation with the equivalent strain.The peak occurrence time and duration of the two are synchronized,but the action directions are different.The layered pouring bias changes the structure damage distribution and damage range,and the water cooling bias Reduce peak damage and peak duration.4.The influence and applicability of different damage models on the hydration heat temperature damage of the cap are discussed.The analysis results show that the different damage models are inconsistent in application scope,and the damage models should be selected reasonably in different damage areas.