發(fā)布時間：2019-05-10 04:23

【摘要】：隨著我國城市化進程和基礎(chǔ)建設(shè)的加快，混凝土耐久性問題也越來越得到人們的重視。本文依托于國家科技支撐計劃項目-跨海集群工程混凝土結(jié)構(gòu)120年使用壽命保障關(guān)鍵技術(shù)，研究了無損檢測技術(shù)在混凝土耐久性質(zhì)量控制方面的應(yīng)用。根據(jù)FICK第二定律可知，氯離子擴散系數(shù)與鋼筋保護層厚度對混凝土結(jié)構(gòu)使用年限有著非常重要的影響。因此，本文重點研究了利用WENNER、探地雷達等無損檢測技術(shù)方法對混凝土耐久性質(zhì)量進行控制的應(yīng)用，具體研究成果如下 1、通過開展現(xiàn)場試驗、足尺模型與室內(nèi)試驗，建立WENNER法與RCM法兩種試驗方法所測得的混凝土電阻率與混凝土氯離子擴散系數(shù)的相關(guān)性。試驗表明，足尺模型試驗測得電阻率隨齡期變化規(guī)律更加符合實體構(gòu)件的電阻率隨齡期變化規(guī)律，，混凝土電阻率ρ與混凝土氯離子擴散系數(shù)D的關(guān)系式為D=128.486。通過試驗建立了實體構(gòu)件混凝土電阻率ρ與氯離子擴散系數(shù)D的關(guān)系式D=128.4861.02ρ3.05，解決了現(xiàn)場構(gòu)件無法進行破損性的氯離子擴散系數(shù)檢測這一問題，實現(xiàn)了現(xiàn)場簡單快速的控制混凝土耐久性質(zhì)量的目標(biāo)。 2、通過開展港珠澳大橋沉管隧道足尺模型試驗確定了探地雷達測混凝土保護層厚度的偏差修正值為0.87mm。使用探地雷達對港珠澳大橋沉管隧道預(yù)制構(gòu)件的10個管節(jié)共計64個節(jié)段的5600多根鋼筋位置的混凝土保護層厚度進行了檢測，分析總結(jié)了沉管隧道預(yù)制構(gòu)件墻外側(cè)、墻內(nèi)側(cè)、底板外側(cè)的保護層厚度的偏差分布，達到了精準控制混凝土耐久性質(zhì)量的要求。 3、對比分析了沉管隧道預(yù)制構(gòu)件墻外側(cè)、墻內(nèi)側(cè)、底板外側(cè)保護層厚度偏差分布的差異。沉管隧道預(yù)制構(gòu)件底板外側(cè)保護層厚度偏差比墻外側(cè)、墻內(nèi)側(cè)的偏差都小，因此要加強沉管隧道預(yù)制構(gòu)件墻外側(cè)、墻內(nèi)側(cè)綁扎鋼筋、模板支護時的質(zhì)量監(jiān)測。
[Abstract]:With the acceleration of urbanization and infrastructure in China, the durability of concrete has been paid more and more attention. Based on the key technology of 120 years service life guarantee of concrete structure in cross-sea cluster project, the application of nondestructive testing technology in durability quality control of concrete is studied in this paper. According to FICK's second law, the chloride diffusion coefficient and the thickness of steel bar cover have a very important influence on the service life of concrete structures. Therefore, this paper focuses on the application of WENNER, ground penetrating radar and other nondestructive testing techniques to control the durability quality of concrete. The specific research results are as follows: 1. Through field test, full-scale model and laboratory test, The correlation between the concrete resistivity measured by the WENNER method and the RCM method and the chloride diffusion coefficient of the concrete is established. The test results show that the variation of resistance with age is more in accordance with the law of resistance of solid members with age, and the relationship between resistance of concrete and chloride diffusion coefficient D of concrete is D 鈮

本文編號：2473336