| 摘要: |
| 采用砂浆棒长度法研究了废旧轮胎橡胶粉对碱骨料反应的影响.比较了不同掺量、不同粒径废旧轮胎橡胶粉对碱骨料反应膨胀的抑制作用.结果表明：废旧轮胎橡胶粉对碱骨料反应早期有很强的抑制作用，膨胀降低率可达到50%以上，后期抑制作用减弱到30%左右；当废旧轮胎橡胶粉掺量为25%（质量分数）时，其对膨胀的抑制作用达到最佳效果，在28d龄期的膨胀抑制率可达到35%，随着废旧轮胎橡胶粉掺量的继续增大，这种膨胀抑制作用的效果增长不明显；在3种粒径的废旧橡胶粉中，粒径为119μm的废旧轮胎橡胶粉抑制碱骨料反应的效果最好，但抑制程度提高幅度不大；粒径较小、具有弹性的废旧轮胎橡胶粉在水泥砂浆中充当了应力的集中中心，能有效减少裂纹的产生，且其具有疏水性能，也能引入一定量的空气，可缓解碱骨料反应时胶体吸水产生的膨胀压力，从而限制水泥砂浆内部裂纹的扩展，减弱了碱骨料反应对基体的破坏作用. |
| 关键词: 废旧轮胎橡胶粉 抑制作用 碱骨料反应 |
| DOI：103969/j.issn1007 9629201306011 |
| 分类号: |
| 基金项目:辽宁省高等学校科研项目——重点实验室项目（LS2010045）；建筑安全与环境国家重点实验室开放基金资助项目（201202）；大连市科学技术基金资助项目（2009J22DW032） |
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| Inhibition Effect of Scrap Rubber Powder on Alkali Aggregate Reaction |
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WANG Bao min1, HAN Yu1, LIU Yan rong2, TU Ni1
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1.School of Civil Engineering, Dalian University of Technology, Dalian 116024, China;2.Manzhouli Civil Building Engineering Quality Testing Center, Manzhouli 021400, China
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| Abstract: |
| The influence of scrap rubber powder on alkali aggregate reaction（AAR） was studied by the mortar bar length method. The effect of rubber powder contents and rubber powder sizes on AAR were compared. The results indicate that the incorporation of scrap rubber powder can suppress the expansion of samples which caused by alkali aggregate reaction at the early age, and the inhibition rate of expansion can be more than 50%. The inhibition effect is weakened to 30% at the later age. The inhibition effect reaches ideal degree when the rubber content is 25%(by mass), its expansion inhibitory ratio can reach 35%. The growth of inhibition effect is not obvious with the increase of rubber powder content. Among the three different particle sizes of rubber, the 119μm has the best inhibition effect on AAR, but the improvement of inhibition is insignificant. The elastic scrap rubber powder with small particle sizes acts as concentration center of stress, they can reduce the emerging of crack effectively. The scrap rubber powder are hydrophobic, and they can induce air. Air bubble together with the scrap rubber powder plays a part in easing up the bulbs of pressure generated by AAR, then restricts the internal crack extension in cement mortar, and weakens the damage of AAR on the matrix. |
| Key words: scrap rubber powder inhibition effect alkali aggregate reaction(AAR) |
