广西大学学报(自然科学版)
廣西大學學報(自然科學版)
엄서대학학보(자연과학판)
JOURNAL OF GUANGXI UNIVERSITY (NATURAL SCIENCE EDITION)
2015年
4期
883-889
,共7页
混凝土%氯离子扩散系数%表面氯离子浓度%时变性%解析解
混凝土%氯離子擴散繫數%錶麵氯離子濃度%時變性%解析解
혼응토%록리자확산계수%표면록리자농도%시변성%해석해
concrete%chloride diffusion coefficient%surface chloride concentration%time depend-ence%close-form solution
为了准确分析氯离子侵蚀环境下混凝土结构的耐久性,同时考虑表面氯离子浓度和扩散系数的时变性对混凝土中氯离子扩散过程的影响。首先应用变量代换法、Laplace积分变换及其逆变换,建立了同时考虑混凝土表面氯离子浓度和扩散系数时变性的氯离子扩散解析解。通过算例分析验证了解析解的正确性,并对比研究了表面氯离子浓度和扩散系数的时变性对混凝土中氯离子扩散的影响。结果表明,两个参数的时变性都会对混凝土中氯离子浓度分布产生显著影响,且随着计算深度增大,双时变影响越显著,其中扩散系数的时变性影响更大。因而,混凝土结构耐久性分析和设计中应同时考虑表面氯离子浓度和氯离子扩散系数的时变性。
為瞭準確分析氯離子侵蝕環境下混凝土結構的耐久性,同時攷慮錶麵氯離子濃度和擴散繫數的時變性對混凝土中氯離子擴散過程的影響。首先應用變量代換法、Laplace積分變換及其逆變換,建立瞭同時攷慮混凝土錶麵氯離子濃度和擴散繫數時變性的氯離子擴散解析解。通過算例分析驗證瞭解析解的正確性,併對比研究瞭錶麵氯離子濃度和擴散繫數的時變性對混凝土中氯離子擴散的影響。結果錶明,兩箇參數的時變性都會對混凝土中氯離子濃度分佈產生顯著影響,且隨著計算深度增大,雙時變影響越顯著,其中擴散繫數的時變性影響更大。因而,混凝土結構耐久性分析和設計中應同時攷慮錶麵氯離子濃度和氯離子擴散繫數的時變性。
위료준학분석록리자침식배경하혼응토결구적내구성,동시고필표면록리자농도화확산계수적시변성대혼응토중록리자확산과정적영향。수선응용변량대환법、Laplace적분변환급기역변환,건립료동시고필혼응토표면록리자농도화확산계수시변성적록리자확산해석해。통과산례분석험증료해석해적정학성,병대비연구료표면록리자농도화확산계수적시변성대혼응토중록리자확산적영향。결과표명,량개삼수적시변성도회대혼응토중록리자농도분포산생현저영향,차수착계산심도증대,쌍시변영향월현저,기중확산계수적시변성영향경대。인이,혼응토결구내구성분석화설계중응동시고필표면록리자농도화록리자확산계수적시변성。
The time-dependency of the surface chloride concentration and diffusion coefficient of concrete was taken into consideration to investigate the process of chloride diffusion in concrete. The variable substitution method, the Laplace integral transformation and its inverse transformation were applied to yield the closed-form solutions ( CFS) of the governing partial differential equation descri-bing the diffusion process. The CFS was proved by the Finite Element Method. Examples were con-sidered to demonstrate the accuracy and applicability of the proposed CFS. Results show that the time-dependency of the two parameters has significant influence on the chloride diffusion, and as the computation depth increases, the influence becomes more significant. Moreover, the time-dependen-cy of the diffusion coefficient has a more important impact than the surface chloride concentration. The time-dependency of the surface chloride concentration and diffusion coefficient should be consid-ered to predict the service life and design the durability of concrete structures more accurately.