合肥工业大学学报(自然科学版)
閤肥工業大學學報(自然科學版)
합비공업대학학보(자연과학판)
JOURNAL OF HEFEI UNIVERSITY OF TECHNOLOGY(NATURAL SCIENCE)
2015年
6期
804-809
,共6页
盐渍土%半埋混凝土%氯离子%耐久性%寿命预测
鹽漬土%半埋混凝土%氯離子%耐久性%壽命預測
염지토%반매혼응토%록리자%내구성%수명예측
saline soil%partially-exposed concrete%chloride ion%durability%service life prediction
文章在现场调查的基础上,针对青海察尔汗盐湖至格尔木高速公路上使用的混凝土进行氯盐快速腐蚀试验和氯离子测试实验。试验结果表明:混凝土相对动弹性模量先上升后下降;混凝土吸附区氯离子的分布规律为先随着距表层距离的增加而增加,在0.75 cm处达到最大值,之后随着距表层距离的增加而下降。结合半埋状态下混凝土各部位和周围盐渍土之间的离子交换传输机理,以及氯离子的腐蚀机理,对半埋混凝土状态下钢筋混凝土的使用寿命进行了预测。结果表明:半埋状态下混凝土和周围盐渍土之间的离子交换机理是外部“蒸发‐浓缩”和毛细管吸附,内部为扩散;氯离子在半埋混凝土靠近表层处浅层区域的传输机理主要是毛细管吸入,深层区域为扩散;钢筋混凝土腐蚀的主要原因是氯离子使钢筋表面钝化膜破坏,形成腐蚀电池并产生孔蚀,随着铁锈体积增大,导致混凝土保护层开裂。最后,研究得出的青海氯盐渍土地区的半埋钢筋混凝土使用寿命和钢筋保护层厚度之间的关系与调查结果基本一致,说明了文中的寿命预测方法的合理性。
文章在現場調查的基礎上,針對青海察爾汗鹽湖至格爾木高速公路上使用的混凝土進行氯鹽快速腐蝕試驗和氯離子測試實驗。試驗結果錶明:混凝土相對動彈性模量先上升後下降;混凝土吸附區氯離子的分佈規律為先隨著距錶層距離的增加而增加,在0.75 cm處達到最大值,之後隨著距錶層距離的增加而下降。結閤半埋狀態下混凝土各部位和週圍鹽漬土之間的離子交換傳輸機理,以及氯離子的腐蝕機理,對半埋混凝土狀態下鋼觔混凝土的使用壽命進行瞭預測。結果錶明:半埋狀態下混凝土和週圍鹽漬土之間的離子交換機理是外部“蒸髮‐濃縮”和毛細管吸附,內部為擴散;氯離子在半埋混凝土靠近錶層處淺層區域的傳輸機理主要是毛細管吸入,深層區域為擴散;鋼觔混凝土腐蝕的主要原因是氯離子使鋼觔錶麵鈍化膜破壞,形成腐蝕電池併產生孔蝕,隨著鐵鏽體積增大,導緻混凝土保護層開裂。最後,研究得齣的青海氯鹽漬土地區的半埋鋼觔混凝土使用壽命和鋼觔保護層厚度之間的關繫與調查結果基本一緻,說明瞭文中的壽命預測方法的閤理性。
문장재현장조사적기출상,침대청해찰이한염호지격이목고속공로상사용적혼응토진행록염쾌속부식시험화록리자측시실험。시험결과표명:혼응토상대동탄성모량선상승후하강;혼응토흡부구록리자적분포규률위선수착거표층거리적증가이증가,재0.75 cm처체도최대치,지후수착거표층거리적증가이하강。결합반매상태하혼응토각부위화주위염지토지간적리자교환전수궤리,이급록리자적부식궤리,대반매혼응토상태하강근혼응토적사용수명진행료예측。결과표명:반매상태하혼응토화주위염지토지간적리자교환궤리시외부“증발‐농축”화모세관흡부,내부위확산;록리자재반매혼응토고근표층처천층구역적전수궤리주요시모세관흡입,심층구역위확산;강근혼응토부식적주요원인시록리자사강근표면둔화막파배,형성부식전지병산생공식,수착철수체적증대,도치혼응토보호층개렬。최후,연구득출적청해록염지토지구적반매강근혼응토사용수명화강근보호층후도지간적관계여조사결과기본일치,설명료문중적수명예측방법적합이성。
Based on the field investigation ,the chlorine accelerated corrosion test and chlorine ion testing exper‐iment on the concrete used in the highway between Chaerhan Salt Lake and Golmud ,Qinghai Province were made .The experimental result shows that the dynamic elastic modulus of concrete increases first ,afterwards deceases as dry‐wet circulation increases .And the distribution of chlorine ion in adsorption zone increases first with the increase of the distance from the surface ,reaching the maximum at 0.75 cm ,then decreases with the increase of the distance from the surface .Based on the ion transport mechanism model between the partially‐exposed concrete and sulfate soil around and the corrosion mechanism of the chloride ion ,the service life of partially‐exposed reinforced concrete was predicted .The results show that the transport mechanism of the chloride ion in the shallow area near the surface is “evaporation‐enrichment”and capillary suction ,and in the deep area is diffusion of the partially‐exposed concrete ;the corrosion mechanism of the reinforced concrete is that the chloride ion makes the passive film damage on the surface of steel ,producing the corrosion cell and pitting corrosion ,with the rust volume increases ,the concrete protective cover cracks .Finally ,the relation‐ship between the service life of partially‐exposed reinforced concrete and the thickness of the cover was gotten , and the service condition of the partially‐exposed reinforced concrete in chloride saline soil areas of Qinghai Province was basically identical with the prediction ,which can explain the rationality of this paper .