偶联剂改性沥青与卵碎石集料界面性能研究

Interfacial Performance of Coupling Agent Modified Asphalt and Egg Crushed Stone Aggregate

为了改善酸性卵碎石集料与沥青粘附性,利用硅烷偶联剂KH550对沥青进行改性。采用针入度、延度、软化点试验分析了偶联剂掺量对沥青性质的影响。采用红外光谱分析、沥青-卵碎石粉交互作用能力测试、低温黏结性试验和沥青混合料水敏感性试验,研究了偶联剂对沥青与卵碎石集料的界面作用。结果表明:经过偶联剂处理的卵碎石粉末的红外光谱存在明显的CH_2吸收带,证明了在偶联剂作用下卵碎石表面生成了聚硅氧烷。沥青的软化点随偶联剂掺量的增多先增大后减小,延度和针入度随偶联剂掺量的增多先减小后增大。偶联剂掺量为0.6%时,沥青-卵碎石粉体系的车辙因子G~*/sinδ与交互作用系数B值最高。在该掺量下,卵碎石低温脱石量降低了50.7%;相对未改性沥青混合料,水敏感性试验后偶联剂改性沥青混合料的残留劈裂强度比提高了7.9%。硅烷偶联剂显著提高了卵碎石与沥青的界面性能。

In order to improve adhesion ability between acidity egg crushed stone aggregate and asphalt,the asphalt was modified by silane coupling agent KH550. The penetration,ductility and softening point test were used to analyze the effect of coupling agent content on properties of asphalt. The interfacial interaction of coupling agent modified asphalt and egg crushed stone aggregate was studied by IR spectroscopy,asphalt-egg crushed stone powder interaction ability test,low temperature adhesion test and asphalt mixture moisture induced sensitivity test. Results show that CH2 significantly appears in the IR spectra of egg crushed stone powder treated by silane coupling agent,which proves that polysiloxane is formed on the surface of egg crushed stone under the action of coupling agent. The soft point of asphalt increases firstly and decreases finally with the dosage increasing of coupling agent. The ductility and penetration has a contrary law with the dosage increasing of coupling agent. The rutting factor G-＊/sinδand interaction coefficient B of asphalt-egg crushed stone powder system are the best under the 0. 6% dosage of coupling agent,under which,the removal amount of egg crushed stones at low temperature is reduced by 50. 7%. The residual splitting strength ratio of coupling agent modified asphalt mixture isincreased by 7. 9% compared to unmodified asphalt mixture after moisture induced sensitive test. The interfacial property between the crushed stone and asphalt is significantly improved by silane coupling agent.