CAJ | 학술논문

为了研究混凝土在冻融交替与盐类侵蚀双重因素作用下的抗冻耐久性能，根据季节冻土区大安境内盐渍土中主要易溶盐的类型与含量，配制了3种质量分数的复合盐侵蚀溶液，制备了普通混凝土、2种引气混凝土及2组粉煤灰混凝土试件，进行盐蚀快速冻融循环试验，对盐冻破坏后混凝土的质量损失、动弹性模量衰减及其微观结构进行分析。试验结果表明：在冻融循环作用下，复合盐加剧了混凝土的冻融剥蚀破坏；混凝土的冻害程度与侵蚀盐溶液的质量分数、冻融循环次数、混凝土的含气量、粉煤灰掺量等因素有关；造成混凝土发生盐冻破坏的原因有水结成冰的膨胀压力，或冰与水的渗透压力以及复合盐与水泥水化产物发生的化学侵蚀和盐类的结晶膨胀，其中，盐类结晶压对混凝土内部结构的破坏更严重。
위료연구혼응토재동융교체여염류침식쌍중인소작용하적항동내구성능，근거계절동토구대안경내염지토중주요역용염적류형여함량，배제료3충질량분수적복합염침식용액，제비료보통혼응토、2충인기혼응토급2조분매회혼응토시건，진행염식쾌속동융순배시험，대염동파배후혼응토적질량손실、동탄성모량쇠감급기미관결구진행분석。시험결과표명：재동융순배작용하，복합염가극료혼응토적동융박식파배；혼응토적동해정도여침식염용액적질량분수、동융순배차수、혼응토적함기량、분매회참량등인소유관；조성혼응토발생염동파배적원인유수결성빙적팽창압력，혹빙여수적삼투압력이급복합염여수니수화산물발생적화학침식화염류적결정팽창，기중，염류결정압대혼응토내부결구적파배경엄중。
In order to study the frost resistance and durability of concrete structures under double factors of salts attack and freezing-thawing cycles in seasonal frozen soil area,multi-salt solution with three kinds of mass fraction and water were prepared according to the type and quantity of the main dissolved salts in the spring soil of Daan region.Specimens of ordinary concrete with different mixture ratios,two kinds of air-entraining concrete and two kinds of fly-ash concrete were prepared for the multiple salts and freezing-thawing cycle tests.The mass loss,dynamic elastic modulus reduction and microstructure of tested samples were analyzed.Results showed that concrete erosion was aggravated by multi-salt under the action of freezing-thawing cycles.The degree of frozen damage was related to the mass fraction of salt solution,times of freezing-thawing cycle,air content in concrete and fly-ash addition ratio.Reasons that lead salt-frozen damage occur were expansion pressure produced during the course of water turning into ice,the seepage pressure of ice and water and the chemical erosion and crystalline swelling of salt from the reaction between multi-salt and cement hydration production,among which salt crystallization played more important role in the damage of concrete internal structure.