长期处于海洋或滨海环境的锚固体系会受到离子侵蚀导致耐久性下降。为研究离子侵蚀环境中锚固体的锚固性能,本文通过室内试验,分析了不同腐蚀环境和不同腐蚀时间下普通锚固体和预应力锚固体的表面损伤、锚杆强度以及砂浆-锚杆界面间的粘结强度。结果表明:腐蚀龄期增加以及给锚杆施加预应力会加速锚杆的腐蚀;锚杆在腐蚀初期会在表面形成一层氧化膜,所以不同腐蚀溶液对锚杆的腐蚀效果不明显;施加了预应力的锚杆会对腐蚀龄期更敏感,其极限抗拉强度下降得更快;砂浆-锚杆界面间的粘结强度随着腐蚀龄期近似呈线性变化,施加预应力后,界面间粘结强度下降得更快;腐蚀溶液对砂浆-锚杆界面粘结强度起削弱作用的强弱顺序为混合溶液＞硫酸钠溶液＞氯化钠溶液。研究成果可为长期处在海洋和滨海环境中服役的锚固体系的耐久性研究提供依据。
Anchorage body in long-term marine or coastal environments are subject to ionic erosion leading to durability degradation. In order to study the anchorage performance of anchorage body in ionic erosion environment, the surface damage, anchor strength, and bond strength between mortar and bolt of ordinary and prestressed anchorage body were analyzed under different corrosion environments and corrosion times through long-term immersion test. The results showed that the corrosion period and prestressing of the bolt accelerated their corrosion. In the initial stage of corrosion, an oxide film was formed on the surface of the bolt, so the corrosion effect of different corrosion solutions on the anchor rods was not significant. The bolt with prestress were more sensitive to the corrosion period, and their ultimate tensile strength decreases faster. The bond strength between mortar and bolt showed a linear change with the corrosion period, and the bond strength decreased faster with the increase of corrosion time if the bolt were prestressed. The weakening effect of corrosion solutions on the bond strength between mortar and bolt was in the order of mixed solution > sodium sulfate solution > sodium chloride solution. The research results can provide a basis for the durability study of anchorage body that serve in environments such as oceans and coastal saline soil for a long time.
[1] 李富民, 刘贞国, 陆荣, 等. 硫酸盐腐蚀锚索结构锚固性能退化规律试验研究[J]. 岩石力学与工程学报, 2015, 34(8): 1581-1593.
[2] 郝贠洪, 韩燕, 樊磊, 等. 冲击荷载下盐腐蚀水泥砂浆接触损伤研究[J]. 铁道学报, 2018, 40(10): 144-151.
[3] 张永兴, 徐洪. 砂浆受腐蚀锚固体的锚固特性试验研究[J]. 岩土力学, 2010, 31(10): 3058-3062.
[4] Huo R K, Li S G, Ding Y. Experimental study on physicochemical and mechanical properties of mortar subjected to acid corrosion[J]. Advances in Materials Science and Engineering, 2018, 2018: 2-10.
[5] Lee H S, Balasubramanian B, Gopalakrishna G V T, et al. Durability performance of CNT and nanosilica admixed cement mortar[J]. Construction and Building Materials, 2018, 159: 463-472.
[6] Chao L C, Kuo C P. Ternary blends of high aluminate cement, fly ash and blast-furnace slag for sewerage lining mortar[A] //IOP Conference Series: Materials Science and Engineering [C]. Bristol: IOP Publishing, 2018:012023.
[7] 牛全林, 张勇. 矿物质混合材对水泥砂浆抗硫酸盐腐蚀的影响[J]. 硅酸盐学报, 2006, 34(1):114-117.
[8] Xu Z, Viehland D. Observation of a mesostructure in calcium silicate hydrate gels of portland cement[J]. Physical Review Letters, 1996, 77(5): 952-955.
[9] Viehland D, Li J F, Yuan L J, et al. Mesostructure of calcium silicate hydrate (C-S-H) gels in portland cement paste: short-range ordering, nanocrystallinity, and local compositional order[J]. Journal of the American Ceramic Society, 1996, 79(7): 1731-1744.
[10] Zhang X G, Zuo G Q, Memon S A, et al. Effects of initial defects within mortar cover on corrosion of steel and cracking of cover using X-ray computed tomography[J]. Construction and Building Materials, 2019, 223: 265-277.
[11] Mcdonald P J, Korb J P, Mitchell J, et al. Surface relaxation and chemical exchange in hydrating cement pastes: a two-dimensional NMR relaxation study[J]. Physical Review E, 2005, 72(1): 011409.
[12] Mcdonald P J, Mitchell J, Mulheron M, et al. Two-dimensional correlation relaxation studies of cement pastes[J]. Magnetic Resonance Imaging, 2007, 25(4): 470-473.
[13] Monteilhet L, Korb J P, Mitchell J, et al. Observation of exchange of micropore water in cement pastes by two-dimensional T2-T2 nuclear magnetic resonance relaxometry[J]. Physical Review E, 2006, 74(6): 061404.
[14] 何真, 郑巧, 蔡新华. 水化硅酸钙纳米颗粒间水特性[J]. 水利学报, 2014, 45(2): 205-212.
[15] Filho F F, Copuroglu O, Schlangen E, et al. Determination of loss of reinforcement due to corrosion through X-ray computer micro-tomography[J]. Materials, 2021, 14(4): 893-907.
[16] 王玉杰, 尹韬, 孙兴松, 等. 丰满老坝加固预应力锚索服役近30年后性能评价研究[J]. 岩石力学与工程学报, 2022, 41(1): 62-69.
[17] 李铮, 汪波, 何川, 等. 多重防腐锚杆抗腐蚀性试验研究[J]. 岩土力学, 2015, 36(4): 1071-1077,1146.
[18] Shi J, Wu M, Ming J. Long-term corrosion resistance of reinforcing steel in alkali-activated slag mortar after exposure to marine environments[J]. Corrosion Science, 2021, 179: 109175.
[19] Zhang P, Liu Z L, Wang Y, et al. 3D neutron tomography of steel reinforcement corrosion in cement-based composites[J]. Construction and Building Materials, 2018, 162: 561-565.
[20] Qiu Q W, Zhu J H, Dai J G. In-situ X-ray microcomputed tomography monitoring of steel corrosion in engineered cementitious composite (ECC)[J]. Construction and Building Materials, 2020, 262: 120844.
[21] 李国维, 汪井秋, 吴建涛, 等. 侵蚀环境下预应力 GFRP 锚杆结构应力松弛特征[J]. 岩石力学与工程学报, 2020, 39(5): 877-886.
[22] 李聪, 朱杰兵, 汪斌, 等. 腐蚀环境下预应力锚筋的耐久性试验研究[J]. 岩石力学与工程学报, 2015, 34(增1): 3356-3364.
[23] 朱杰兵, 李聪, 刘智俊, 等. 腐蚀环境下预应力锚筋损伤试验研究[J]. 岩石力学与工程学报, 2017, 36(7): 1579-1587.
[24] 中冶集团建筑研究总院. 岩土锚杆(索)技术规(CECS22:2005) [S]. 北京: 中国计划出版社, 2005.
[25] 汪小刚, 陈益峰, 卢波, 等. 枢纽工程重要构筑物(群)与地质环境互馈作用机制与控制技术[J]. 岩土工程学报, 2022,44(7):1220-1238.
[26] 李英勇, 张思峰, 王松根, 等. 预应力锚固结构腐蚀介质作用下的耐久性试验研究[J]. 岩石力学与工程学报, 2008, 201(5): 1626-1633.
[27] 赵健, 冀文政, 曾宪明, 等. 应力腐蚀对锚杆使用寿命影响的试验研究[J]. 岩石力学与工程学报, 2007, 192(增1): 3427-3431.
[28] 陈庆玉,王桂林,徐洪,等.锚固砂浆硫酸盐腐蚀损伤试验研究[J].地下空间与工程学报,2011,7(2):291-295.
[29] 魏支援, 王勇, 龚晓南,等. 富水砂加卵石双地层锚索现场试验及数值模拟[J]. 地下空间与工程学报, 2021, 17(5): 1507-1516.
