The Correlation of Chloride Diffusion Coefficient and Concrete Maturity Value and Its Application in Hong Kongâ•fiZhuhaiâ•fiMacao Bridge Engineering
نویسندگان
چکیده
The correlation of chloride diffusion coefficient and concrete maturity value within 56 days of curing was investigated by the chemically combined water content method, rapid chloride migration (RCM) test, and concrete maturity test. The experimental results showed that chloride diffusion coefficient of concretes decreased not only with increasing curing ages but also with increasing curing temperature, which can promote the hydration degree of cementitous materials. There is a significant correlation between the chloride diffusion coefficient of indoor cured specimens and the concrete maturity value when expressed as a power function (R2 = 0.976). In addition, the calculated values of concrete maturity for outdoor specimens, obtained using the power function, agree well with the measured values. As a result, the measured concrete maturity values can be used to predict the chloride diffusion coefficient of concrete. And then in this project, when the immersed tube tunnels were placed in seawater, the recommended value and the control values of concrete maturity were 21,064 and 13,926°C h-1, respectively. Furthermore, the ages of the tunnels placed in seawater can be appropriately adjusted by calculation when considering the external curing temperature and heat of hydration of cementitous materials.
منابع مشابه
Application of the Resistivity in Quality Control of Concrete Durability for the Hong Kongâ•fiZhuhaiâ•fiMacao Bridge
Engineering uses the chloride ion diffusion coefficient as the durability of concrete quality control indicators under the marine environment, due to the chloride ion diffusion coefficient and the electrical resistivity of concrete parameters are reflected in the concrete pore structure, and resistivity testing is convenient, fast advantages, the resistivity alternative chloride ion diffusion c...
متن کاملModification of Displacement Coefficient Method in Estimation of Target Displacement for Regular Concrete Bridges Based on ASCE 41-06 Standard
Displacement Coefficient Method (DCM) stipulated in the ASCE 41-06 standard is becoming the preferred method for seismic rehabilitation of buildings in many high-seismic-hazard countries. Applications of the method for non-building constructions such as bridges are beyond the scope of this standard. Thus its application to this kind of structure should be approached with care. Target displaceme...
متن کاملبررسی شاخص کاهش پخش کلراید در بتن از روشهای تجربی و تحلیلی
Diffusion coefficient is one of the parameters which can describe the rate of chloride ion diffusion in concrete. This can be obtained by the chloride ion profile. By determining this factor,one can predict when the chloride ion concentration on the reinforcement surface reaches a critical value,and the cover tickness which is needed for preventing corrosion. Time and distance dependency of ...
متن کاملApplication of J-BMS to Performance Evaluation and Remaining Life Prediction of an Existing RC Bridge
This paper describes a method of performance evaluation and remaining life prediction for an aged reinforced concrete (RC) T-girder bridge by J-BMS RC version via close visual inspection data, and also verifies the assessment results obtained as outputs from the Bridge Rating Expert System (RC-BREX) which is a subsystem of the J-BMS, to evaluate the effectiveness of the system. The Bridge Manag...
متن کاملPrediction of Service Life in Concrete Structures based on Diffusion Model in a Marine Environment using Mesh Free, FEM and FDM Approaches
Chloride-induced corrosion is a key factor in the premature corrosion of concrete structures exposed to a marine environment. Fick's second law of diffusion is the dominant equation to model diffusion of chloride ions. This equation is traditionally solved by Finite Element Method (FEM) and Finite Difference Method (FDM). Although these methods are robust and efficient, they may face some numer...
متن کامل