东南大学学报(自然科学版)
東南大學學報(自然科學版)
동남대학학보(자연과학판)
JOURNAL OF SOUTHEAST UNIVERSITY
2014年
2期
401-405
,共5页
宦文娟%张云升%刘国建%赵鹏
宦文娟%張雲升%劉國建%趙鵬
환문연%장운승%류국건%조붕
黏土砖%冻融循环%性能劣化%微结构演化
黏土磚%凍融循環%性能劣化%微結構縯化
점토전%동융순배%성능열화%미결구연화
clay brick%freeze-thaw cycle%performance deterioration%microstructure evolution
系统研究了黏土红砖在冻融环境下的外观、质量损失率及相对动弹模量变化;采用压汞法分析了黏土红砖冻融前后的孔径分布变化规律,并应用X射线计算机断层扫描技术原位定量追踪了黏土红砖冻融环境下的三维孔结构演化过程.结果表明,冻融初期黏土红砖外观破坏不明显,35次冻融循环后开始出现宏观裂纹,65次冻融循环后分层,并沿分层界面剥落.黏土红砖质量及相对动弹模量随冻融次数的增加均表现出先略有增大再下降的规律,并且质量变化敏感.孔结构分析结果表明,65次冻融循环后黏土红砖平均孔径增大近4倍,气孔总体积增加23%,体积为0.01~0.1 mm3的气孔数量和体积显著增多,抗冻性能明显降低.
繫統研究瞭黏土紅磚在凍融環境下的外觀、質量損失率及相對動彈模量變化;採用壓汞法分析瞭黏土紅磚凍融前後的孔徑分佈變化規律,併應用X射線計算機斷層掃描技術原位定量追蹤瞭黏土紅磚凍融環境下的三維孔結構縯化過程.結果錶明,凍融初期黏土紅磚外觀破壞不明顯,35次凍融循環後開始齣現宏觀裂紋,65次凍融循環後分層,併沿分層界麵剝落.黏土紅磚質量及相對動彈模量隨凍融次數的增加均錶現齣先略有增大再下降的規律,併且質量變化敏感.孔結構分析結果錶明,65次凍融循環後黏土紅磚平均孔徑增大近4倍,氣孔總體積增加23%,體積為0.01~0.1 mm3的氣孔數量和體積顯著增多,抗凍性能明顯降低.
계통연구료점토홍전재동융배경하적외관、질량손실솔급상대동탄모량변화;채용압홍법분석료점토홍전동융전후적공경분포변화규률,병응용X사선계산궤단층소묘기술원위정량추종료점토홍전동융배경하적삼유공결구연화과정.결과표명,동융초기점토홍전외관파배불명현,35차동융순배후개시출현굉관렬문,65차동융순배후분층,병연분층계면박락.점토홍전질량급상대동탄모량수동융차수적증가균표현출선략유증대재하강적규률,병차질량변화민감.공결구분석결과표명,65차동융순배후점토홍전평균공경증대근4배,기공총체적증가23%,체적위0.01~0.1 mm3적기공수량화체적현저증다,항동성능명현강저.
The changes of appearance,mass loss percentage and relative dynamic elastic modulus of clay brick submitted to freeze-thaw cycles were systematically studied.The mercury intrusion poro-simetry (MIP)was utilized to investigate the pore size distribution before and after freeze-thaw cy-cles.The X-ray computed tomography (CT)was also used to in situ quantitatively observe the evo-lution of the three-dimensional pore structure under freeze-thaw cycles.The results show that the frost damage is slight in the early stages.Macroscopic cracks appear on the surface after 35 freeze-thaw cycles and spalling occurs after 65 cycles.Mass is more sensitive when submitted to freeze-thaw cycles and shows a similar regulation as the relative dynamic elastic modulus with a first gradual increase,followed by a decrease.The pore structure analysis results show that the average pore size increases about 4 times after freeze-thaw cycles with coarse pores increasing by 23% in volume. Simultaneously,the number and the volume of pores with the volume of 0.01 to 0.1 mm3 increase evidently.The frost resistance of clay red brick is reduced consequently.