|
| 摘要: |
| 对不同品质骨料配制的混凝土的抗冻融耐久性和8种骨料(满足或不满足JTGF30—2003规范品质要求)以及3种砂浆在冻融循环过程中的变形特性进行实验,并对骨料微观构造进行观察.结果表明:单纯以骨料表观密度和吸水率来判断其所配制的混凝土的抗冻融耐久性存在不确定性,某些超出JTG F30—2003规范要求骨料配制的混凝土也具有良好的抗冻融耐久性.在混凝土冻融循环过程中骨料和砂浆出现累计残留变形差异,从而对周围砂浆产生压力,使砂浆内部形成拉应力.当砂浆内部拉应力接近或大于砂浆抗拉强度时,混凝土就发生破坏.骨料微观构造对骨料性能产生重大影响. |
| 关键词: 低品质骨料,残留变形,冻融特性 |
| DOI： |
| 分类号:TU528.041 |
| 基金项目:河北省交通厅科研项目(Y-040123)，人事部留学人员科技活动择优资助项目(2004) |
|
| Study on Behavior of Low Quality Aggregate Concrete under Freezing and Thawing Cycle Condition |
|
ZHANG Jin-xi LI Ya-ning JIN Shan-shan FAN Meng
|
| Abstract: |
| Anti-freeze-thaw durability experiment with the concrete made with different quality aggregates was conducted. The deformation characteristic of 8 kinds of aggregates that meet or do not meet quality requirement set forth in JTG F30--2003 and 3 kinds of mortars in freezing and thawing cycle process was investigated. The micro-structure of aggregates was observed. The result indicates that, it is not proper to judge the anti-freeze-thaw durability of concrete only by apparent density and water absorption of aggregate. Some concrete made with low quality aggregate that cannot meet the quality requirement also have the sufficient anti-freeze-thaw durability as shown in the experimental study. The results also indicate that, in the freezing and thawing cycle process of concrete, the residual deformation is accumulated, when the accumulated residual deformation of aggregate is bigger than that of mortar, the tensile stress is resulted in, and the concrete will destruct if the tensile stress is close to or higher than the tensile strength of the mortar. The micro-structure of aggregate has an important effect on aggregate properties. |
| Key words: low quality aggregate,residual deformation,freezing and thawing behavior |
