基于黏弹性分析的复合改性生物沥青抗车辙性能评价

Evaluation on Rutting Resistance and Performance of Compound Modified Bio-asphalt Based on Viscoelastic Analysis

为研究餐饮废油生物沥青的高温抗车辙性能及提升方法,选用有机化蒙脱土(organic montmorillonite,OMMT)作为复合改性剂提升生物沥青的高温性能,采用多应力蠕变恢复试验探究不同生物油和OMMT掺量以及差异化老化状态对各类沥青不可恢复蠕变柔量(J_(nr))、老化敏感性、应力敏感性等指标的影响,并通过四参数Burgers模型对沥青的黏弹性流变参数进行分析.结果表明:在不同老化状态下,餐饮废油生物油的加入明显降低了石油沥青的高温抗车辙性能,而进一步通过OMMT与生物油等掺量复合改性,可使生物沥青的高温抗车辙能力至少恢复至石油沥青的水平,且此高温性能改善效果在经历短期和长期老化后依然显著;与石油沥青相比,生物沥青的老化敏感性发生了略微升高,进一步采用OMMT复合改性后,老化敏感性整体上也呈现出增大趋势;生物油掺量对沥青高温蠕变应力敏感性的影响远低于OMMT掺量和老化的作用,高掺量OMMT复合改性措施的使用需受到应力敏感性要求的限制.此外,基于四参数Burgers流变模型拟合分析发现,随着生物油的加入沥青蠕变柔量的弹性比例及延迟弹性比例均呈减小趋势,黏性蠕变柔量的占比增大,而OMMT的使用与生物油具有完全相反的影响效应.

To address the high temperature rutting resistance and performance improvement of waste cooking oil(WCO)based bio-asphalt,the organic montmorillonite(OMMT)was selected as the compound modifier to improve the high temperature performance of bio-asphalt.The multiple stress creep recovery test was utilized to quantify the influence of bio-oil and OMMT content as well as aging level on the non-recoverable creep compliance(J_(nr)),aging sensitivity and stress sensitivity of various asphalt binders.Viscoelastic rheological parameters of the tested binders were also fitted from the four coefficients Burgers model.Test and analysis results show that the addition of WCO based bio-oil significantly reduces the high temperature rutting resistance of petroleum asphalt under various aging conditions.The further compound Bio/OMMT modification can reach the similar rutting resistance level of petroleum asphalt,in which the performance improvement is still effective after the short-term and long-term aging.The aging sensitivity of the bio-asphalt slightly increases when compared to the petroleum asphalt.Further,compound OMMT modification into bio-asphalt also shows an overall increasing trend of the aging sensitivity.The effect of bio-oil on the binder stress sensitivity at high temperature is much lower than that of the OMMT content and aging effect,and the use of high OMMT content should be limited from the stress sensitivity requirement.Additionally,the fitting results of four coefficients Burgers model show that the use of bio-oil modification decreases the proportion of elasticity and delayed elasticity in creep compliance but increases the viscous part.Meanwhile,the further OMMT compound modification displays the completely opposite impact on the creep compliance proportion of the bio-asphalt.