摘要
沥青与集料的黏附性是沥青混合料水稳定性的关键影响因素,为定量分析沥青与集料之间的黏附性,采用表面自由能理论与改进水煮法分别进行评价。首先采用接触角测量试验测定了25℃条件下沥青、改性沥青、老化沥青与花岗岩、石灰岩、辉绿岩的表面能参数,并计算出不同沥青-集料系统的黏附功与剥落功,以黏附功与剥落功的绝对比值ER作为黏附性评价指标。同时以通过改进水煮法得出的沥青质量损失率F作为定量指标,对表面能理论试验结果加以验证。结果表明:掺入改性剂的90A沥青表面能减小了2.5%~6.2%,改性后的沥青-集料系统水稳定指标ER增加了1.9%~7.8%,黏附性增强,其中掺抗剥落剂的改善效果最好,沥青老化后ER值减小了4.3%~9.2%,黏附性减小。同类型沥青与不同种类集料的黏附性排序为沥青-石灰岩>沥青-辉绿岩>沥青-花岗岩,同种类集料与不同类型沥青的黏附性排序为90PA>90HC>90C≈90H>90A。通过延长水煮时间的改进水煮法得到的黏附性等级差异明显,其结果与表面能评价结果相同。评价指标ER与质量损失率F呈线性负相关,验证了表面能评价体系的可靠性。
Asphalt-aggregate adhesion is a key influencing factor for the water stability of asphalt mixtures.In order to quantitatively analyze the adhesion between asphalt and aggregates,surface free energy theory and improved boiling method were used for the evaluation.First,the surface energy parameters of asphalt,modified asphalt,aged asphalt,granite,limestone and diabase were measured at 25℃ by contact angle measurement test,and the adhesion and exfoliation work of different asphalt-aggregate systems were calculated.The absolute ratio ER between the work of adhesion and the work of exfoliation was used as the evaluation index of adhesion,and the quality loss rate F obtained by improved boiling method as the quantitative index to verify the test results of the surface energy theory.The results show that the surface energy parameters of 90 A asphalt mixed with modifiers reduced by 2.5% to 6.2%,the water stability index ER of the modified asphalt-aggregate system increased by 1.9% to 7.8%,so the adhesion increased,of which the exfoliation agent presented the best improvement effect.However,the ER value of aged asphalt decreased by 4.3% to 9.2%,resulting in the decrease of the adhesion.The adhesion of systems with the same asphalt but different aggregates were ranked as follows:asphalt-limestone>asphalt-diabase>asphalt-granite;whereas that of different asphalt with the same aggregate were ranked as follows:90 PA>90 HC>90 C≈90 H>90 A.The adhesion grades obtained by the improved boiling method with prolonged boiling time were significantly differentiated,and the results were consistent with those of the surface energy evaluation.The evaluation index ER had a linear negative correlation with the mass loss rate F,which further verified the reliability of the surface energy evaluation system.
作者
李昇
张岩
焦凯
LI Sheng;ZHANG Yan;JIAO Kai(College of Civil and Architectural Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Sinohydro Bureau 3rd Co.,Ltd.,Xi’an 710016,China)
出处
《水资源与水工程学报》
CSCD
北大核心
2022年第2期158-164,共7页
Journal of Water Resources and Water Engineering
基金
国家自然科学基金项目(51509200)。
关键词
沥青
集料黏附性
表面能理论
表面自由能
水稳定指标
asphalt
aggregate adhesion
surface energy theory
surface free energy
water stability index