| 摘要: |
| 采用快速砂浆棒法，研究废旧轮胎橡胶粉（WRP）和硅灰（SF）单掺及两者复掺对碱硅酸反应（ASR）引起有害膨胀的抑制作用，并分析WRP粒径对ASR抑制作用的影响；结合扫描电镜和X射线衍射等方法，揭示了两者对活性骨料ASR的抑制机理.结果表明：WRP能够抑制ASR，但其粒径会影响抑制效果，其中0.125 mm （120 目） WRP效果最佳；SF对ASR抑制作用早期较好，而后期不够理想；复掺SF和WRP对抑制ASR膨胀协同作用优异，前期SF发生火山灰反应，水化产物具有缚碱能力，有效抑制ASR负面效应，改善了WRP周边砂浆的密实性，后期WRP利用其物理性能降低膨胀压，从而协同缓解了ASR引起的膨胀. |
| 关键词: 碱硅酸反应 抑制作用 快速砂浆棒法 废旧轮胎橡胶粉 硅灰 |
| DOI：10.3969/j.issn.1007-9629.2023.04.013 |
| 分类号:TU528.01 |
| 基金项目:内蒙古自治区自然科学基金资助项目（2019MS05052）；国家自然科学基金资助项目（51868063） |
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| Mitigation Effect of Waste Rubber Powder and Silica Fume on Alkali-Silica Reaction |
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GAO Peng, WANG Yongbo, XUE Gang, QIN Yuanyu, GU Yuhang
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Department of Civil Engineering， Inner Mongolia University of Science and Technology， Baotou 014010， China
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| Abstract: |
| The mitigation effect of waste rubber powder（WRP）， silica fume（SF） and their binary blends on alkali-silica reaction（ASR） was studied by accelerated mortar-bar test， and the effect of WRP sizes on ASR was compared. The inhibition mechanism on ASR was revealed by means of scanning electron microscope（SEM） and X-ray diffractometer（XRD）. The results show that WRP can inhibit ASR， where the particle size of WRP is a significant parameter. The mitigation effect of the 0.125 mm（120 mesh） WRP is the best . Though the inhibition effect of SF on ASR expansion is good at early stage， it turns worse in late stage. It is found to have an excellent synergistic effect on inhibiting ASR when it is mixed with SF and WRP. The pozzolanic reaction of SF at early stage generates gel with strong alkali absorption capacity， which improves the compactness of microstructure of WRP and mitigates the negative effects of ASR. In the later stage， WRP can effectively reduce the expansion pressure， so they can alleviate the expansion caused by ASR synergistically. |
| Key words: alkali-silica reaction mitigation effect accelerated mortar-bar test waste rubber powder silica fume |
