Analysis Of Temperature To Concrete Bridge Cracking Causes

When the bridge is in use after its construction and completion,the cracks on it will seriously affect the quality and service life of the bridge.As a result,making a comprehensive analysis of the causes of cracks in the bridge concrete and taking positive and effective initiatives is of great significance.The article discussed the causes of cracks in bridge concrete,and analyzed the control measures and treatment methods regarding cracks so as to extend the service life of concrete bridges.Distress in mass concrete is a problem in highway and bridge engineering.These mass concrete structures craze not by external loads,the temperature variation caused by heat of hydration and the temperature stress caused by concrete shrinkage are the main causes for the leaks [1].Therefore,the thermal stress and the temperature control have significant meaning in the mass concrete structures.Thermal cracks will break the structure globality and also decrease the durability of the structures during the construction time.In addition,the temperature variation will have a remarkable affection on the stresses variation of the structures during the service time [2].This paper will discuss the temperature monitoring and the crack control projects of the mass concrete based on the cushion cap of an extradosed cable-stayed bridge which is being constructed.Heat generation of concrete during hardening causes early age temperature rise,and if the associated tendency of volume change is restrained,thermal stresses would be induced and early thermal cracking would result.This issue should be duly considered in concrete bridge construction as the bridge piers as well as other structural members are typically mass concrete members.In this paper,a real-life bridge pier is selected for study.The pier was instrumented to measure its early age temperature rise on site.Finite element analysis was conducted to evaluate the time variations of temperature distributions and thermal stresses induced in the bridge pier.The measurement and analysis results threw light on the evaluation of risk of thermal cracking and planning of temperature control measures in similar projects.To address the problem of sluice concrete easily cracking during construction,this study introduces the crack mechanism of concrete structures.Temperature differences and constraints are the main causes of cracks.Anti-cracking measures should focus on optimizing concrete mixing ratio and improving construction technology.Using simulation calculation to model the actual construction process and temperature control measures,this study analyzes the causes of crack and selects timely and reasonable temperature control measures,which are necessary links in engineering construction.A three-dimensional finite element analysis was conducted for a huge concrete sluice structure.The causes of cracks are discussed,and timely and feasible anti-cracking measures are proposed to provide technical support for project constructionSteel pipe-concrete composite pier,in recent years have been adopted many construction sites of expressways and so on,has been developed for improvement of rapid construction and seismic resistance suitable for the tall bridge pier.It is easy to be cracked by influence of thermal stress accompanying the casting its concrete due to the feature of the structure.So,we carried out the inquiry about some construction sites and made simulation of actual change of temperature by the three dimension thermal analysis.And we executed thermal stress analysis for making clear the mechanism of cracking and some case mainly concerning construction,using the thermal values of materials gained by the simulation.According to the results,we suggested some efficient measurements for control of cracks.