Study On Concrete Performance And Maintenance Measures Of Bridge Pier Under Dry Cold And Large Temperature Difference Environment

When the raw materials,mix ratio,construction technology and the environment in a certain time,the concrete performance will depend on the post-pouring conservation effect.China's northwest region is dry,cold,large temperature difference between day and night,the temperature will affect the hydration of cement in concrete,thereby affecting the strength of concrete and pore structure,and conservation once the end,will not be able to draw moisture from the air to maintain the hydration reaction to continue Development,so in the conservation period to ensure that the concrete hydration required temperature and humidity,while preventing the emergence of temperature cracks.The experience and research results of concrete conservation in conventional areas can not be fully applied to such a harsh environment.In order to keep up with the pace of infrastructure construction in Northwest China and provide practical and theoretical support for the concrete project in this area,The performance and maintenance measures of concrete under the environment of dry and large temperature difference are studied in the background of bridge engineering in the Lake Tema Lake.In this paper,according to the special climatic and environmental conditions in the region,the following three aspects are studied:(1)According to the typical construction mix ratio,the concrete with strength class of C35 and C50 is taken as the research object.The concrete test piers are poured according to the drawing design dimensions at the engineering construction site,and then the concrete of the test piers is repaired by different maintenance methods.At the corresponding age,cores were drilled and sampled,and then the compressive strength of the test pier concrete was tested.The pore structure of the concrete at different ages was tested with the pore-hole analyzer,and the frost resistance of the concrete could be analyzed by using the pore structure parameters.Finally,the electrical flux of concrete was tested to compare the chloride ion permeability of concrete under different curing methods.(2)Using the same batch of concrete with pouring test piers,150 mm × 150 mm × 150 mm cubic compressive specimens and 425 mm × 305 mm × 100 mm crack resistant circular specimens were cast separately.Compressive test specimens are treated with standard maintenance to compare with pier concrete;crack resistant test specimens are placed next to test piers under the same conditions to maintain,test and record the cracking time and width of cracks after each test specimen to compare different maintenance The early crack resistance of concrete is relatively strong.(3)Considering the cost and time consuming of indoor test and field experiment,the numerical simulation method is used to simulate the hydration heat temperature field of the pier by finite element analysis software ANSYS.The concrete strength grade,Different wrapping materials and different package thickness under the piers temperature field distribution,so as to compare the different package conservation program conservation effect.