改性赤泥微粉温拌剂制备及泡沫沥青性能研究

Preparation of modified red mud powder warm mix agent and study on performance of foamed asphalt

分别采用浓度为1 mol/L的HCl、NaOH、NaCl溶液对活化赤泥微粉进行改性,制备改性赤泥微粉温拌剂与泡沫沥青,通过室内试验研究了温拌剂对沥青胶浆低温流变性能与抗老化性能的影响规律。结果表明,活化赤泥微粉的最佳化学改性剂为NaOH;当发泡温度为150℃,温拌剂掺量为20%时,最佳含水率由35%降至30%条件下膨胀率达到7.7倍;温拌剂显著提高了泡沫沥青的低温流变性能,但随着温拌剂掺量的增加,提升效果有所减小;温拌剂进一步提高了沥青的抗老化性能,随着温拌剂掺量的增加,抗热氧老化性能提升效果减弱,抗紫外老化性能提升效果增强。

The activated red mud powder was modified by HCl,NaOH and NaCl solutions with a concentration of 1 mol/L.The modified red mud powder warm mix agent and foamed asphalt were prepared,and the effect of warm mix agent on the low temperature rheological properties and aging resistance of asphalt mortar was studied through laboratory tests.The results showed that the best chemical modifier for the activated red mud powder was NaOH.When the foaming temperature was 150℃and the dosage of warm mix agent was 20%,under the condition of reducing the optimal moisture content from 35%to 30%,the expansion rate reaches 7.7 times.After modification,the warm mix agent significantly improved the low temperature rheological properties of foamed asphalt.And the improvement effect was decreased with the increase of warm mix agent content.The modified red mud powder warm mix agent further improved the anti-aging performance of asphalt.With the increase of the content of warm mix agent,the improvement effect of thermal oxidative aging resistance was weakened but the ultraviolet aging resistance was enhanced.