| Over the years,the experience provided by a variety of practical engineering show that over a period of time after concrete pouring,it will generate a lot of hydration heat to promote the internal temperature rising to a higher value.Especially for mass concrete,because of its relatively thick volume,the internal heat generation due to hydration reaction is extremely difficult to release out,leading to the internal temperature will rise more sharply than in the general concrete structure.Of course is that much more prone to a variety of harmful cracks.When the rising temperature reaches a certain value will slowly begin to cool,at this point the concrete structure is now in a cooling stage.In this process,the concrete structure is easy to cause shrinkage and all kinds of harmful cracks.In brief,when the concrete is in the whole process of heating and cooling,due to the huge difference in temperature will cause internal stress changes,causing the building structure appear all kinds of cracks,directly affects the performance of concrete structure.The cracks control of mass concrete is a complex technology and the theory and practice there often exists a certain deviation.This paper based on actual engineering,solving the common phenomenon of cracks appear easily in the process of mass concrete construction,improving the construction of XiangHu tunnel from the two aspects of construction technology and proportion of mixture,using the orthogonal experimental method to determine the optimal proportion of mixture.This paper first explains the concept of mass concrete in detail and introduces domestic and foreign development and current situation,secondly discusses the reasons of the crack formation and destruction,finally puts forward the methods for the prevention and control of temperature cracks,summarizes the primary technical measures to control concrete cracks.The main research of this paper includes the following aspects:1.The construction technology research of crack control to mass concrete2.Determine the optimal proportion of mixture by orthogonal experimental design theory3.The application of "Three mixed" technology in the mass concrete engineering... |
