Research On Construction Control Of Mass Concrete Structures

With the rapid development of our social economy,many large-scale bridge structures are using at the scene of the mass concrete pouring,and prevent concrete crack of mass concrete structure is very important link in construction control of mass concrete,during the construction process and curing,due to the effect of cement hydration heat,concrete structure deformation occurred during heating and cooling process,under the constraint condition,these produce tensile stresses inside and outside of the mass,the structural crack will appear.S0,in the mass concrete construction process control,the corresponding construction measures should be taken to avoid excessive temperature stress,prevent the formation of temperature cracks.According to the XXX bridge 36 # main piers and Jin-Mongolian Yellow River Bridge main pier bearing platform concrete pouring temperature control,temperature change,tracking observation after casting.Conducted with mass concrete construction control research: through the theoretical analysis of concrete structures,the choice of concrete materials,cooling circulating water pipe,heat preservation maintenance measures of the implementation of the temperature control,real-time monitoring of the entire construction process,realize the effective control of mass concrete construction,guarantee the engineering quality.In this paper,the main content is as follows:(1)Introduce the basic definition of mass concrete,the causes of cracks,the concept of temperature stress,the influence factors of mass concrete construction process control,control targets,construction measures,especially the construction of the importance of temperature control.(2)To understand the basic theory of hydration heat analysis,the finite element method of the fundamental equations of heat conduction,the methods of the main parameters.To understand the basic process and principle of temperature change in concrete structure,analyse the cause of the temperature of cracks,endanger the quality of the engineering entity,analyse the main influencing factors and control method of the temperature stress of mass concrete.(3)This paper introduces the detailed process of temperature control for the construction of main pier of 36# Main Bridge and Jin-Mongolian Yellow River Bridge,and simulates the simulation analysis of the full hydration heat temperature field of mass concrete construction by MIDAS/Civil.(4)Through the construction of the quality of engineering entities and data collected and analyzed,take corresponding temperature measures can be better controlled mass concrete temperature cracks occurrence,for similar projects summed up some experience,provide some reference value.