废弃玻璃粉对ASR膨胀抑制作用机理研究

Inhibiting Mechanism of Waste Glass Powder on ASR Expansion

ASR膨胀是制约废弃玻璃在混凝土中运用的关键因素,也是废弃玻璃混凝土研究热点问题。通过ASTMC1260快速砂浆棒法研究废弃玻璃粉对ASR膨胀的抑制效果,对比不同掺量和不同粒径玻璃粉掺入混凝土时试件不同龄期膨胀率,分析玻璃粉掺量与粒径对ASR膨胀抑制的影响;采用扫描电子显微镜(SEM)对砂浆棒微观结构进行对比分析,探究玻璃粉对ASR膨胀抑制的作用机理。结果表明:掺入玻璃粉对ASR膨胀有一定的抑制效果;玻璃粉掺量越大,对ASR膨胀的抑制效果越好,且持续时间越长;对比0~13μm、13~38μm、38~75μm三组试验发现玻璃粉粒径改变对ASR膨胀影响弱于掺量改变的影响;玻璃粉对ASR膨胀抑制作用与玻璃粉在早期水化过程中更多地参与了火山灰反应有关。

ASR(Alkali-silica reaction)expansion is a key factor restricting the use of waste glass in concrete,and it is also a hot topic in the research of waste glass concrete.The inhibitory effect of waste glass powder on ASR expansion was studied by ASTMC1260 rapid mortar bar method.The expansion ratio of specimens at different ages was compared when the glass powders with different dosages and different particle sizes were mixed into concrete,the glass powder content and particle size were analyzed for ASR expansion inhibition.The microstructure of mortar bar was analyzed by scanning electron microscopy(SEM),and the mechanism of glass powder inhibiting ASR expansion was explored.The results show that the addition of glass powder has a certain inhibitory effect on ASR expansion;the larger the content of glass powder,the better the inhibition effect on ASR expansion,and the longer the duration;the comparison 0-13μm,13-38μm,38-75μm three groups of experiments found that the effect of glass powder particle size change on ASR expansion is weaker than that of content change;the inhibition effect of glass powder on ASR expansion is related to the participation of glass powder in fly ash reaction in the early hydration process.