基于界面增强的橡胶-水泥稳定碎石抗冻抗裂性能研究

Study on the frost resistance and cracking resistance of rubber-cement stabilized macadams based on interface enhancement

【目的】解决橡胶-水泥界面黏结性能不足的问题。【方法】首先采用4种常见的化学改性方法,即氢氧化钠(NaOH)改性、氢氧化钠-尿素(NaOH-Urea)复合改性、硅烷偶联剂KH560改性和硅酸钠(Na_(2)SiO_(3))改性,分别对橡胶颗粒进行改性;然后采用改性后的橡胶颗粒制备橡胶-水泥稳定碎石试件;最后开展冻融、干缩及温缩试验。【结果】分别经NaOH-Urea和KH560改性后的橡胶-水泥稳定碎石的抗冻强度损失几乎无变化,但其冻融前后的无侧限抗压强度均约增大1.5倍;5种橡胶-水泥稳定碎石按其干缩性能从优到劣排序依次为:NaOH改性橡胶-水泥稳定碎石、KH560改性橡胶-水泥稳定碎石、NaOH-Urea改性橡胶-水泥稳定碎石、Na_(2)SiO_(3)改性橡胶-水泥稳定碎石、未改性橡胶-水泥稳定碎石;NaOH-Urea和KH560可以提高橡胶-水泥稳定碎石的温缩性能,而NaOH和Na_(2)SiO_(3)对其温缩性能的改善效果不太理想。【结论】NaOH-Urea和KH560的改性效果较好,其有效增强了橡胶-水泥稳定碎石的抗冻抗裂性能。

[Purposes]In this study,in order to solve the problem of insufficient adhesion performance of rubber-cement interface.[Methods]Firstly,sodium hydroxide oxidation(NaOH),sodium hydroxide oxidation and urea ammoniation(NaOH-Urea),silane coupling agent KH560 and sodium silicate(Na_(2)SiO_(3))were used to treat the surface of the rubber particles.Next,the rubber-cement stabilized macadams test pieces were prepared based on the rubber particles treated with different modification methods.Finally,the temperature shrinkage,drying shrinkage and freezing-thawing test were carried out on the prepared samples.[Findings]The results show that rubber-cement stabilized macadams have almost no change after NaOH-Urea modification and KH560 modification.But the unconfined compressive strength of those samples before and after freezing is increased by about 1.5 times.Drying shrinkage performance of the five examined rubber-cement stabilized macadams is in turn:NaOH modification rubber-cement stabilized macadams,KH560 modification rubber-cement stabilized macadams,NaOH-Urea modification rubber-cement stabilized macadams,Na_(2)SiO_(3)modification rubber-cement stabilized macadams,Unmodified treatment rubber-cement stabilized macadams.The KH560 and NaOH-Urea modification methods improve the temperature resistance of rubber-cement stabilized macadams,while Na_(2)SiO_(3)and NaOH lead to insignificant improvement.[Conclusions]In summary,NaOH-Urea and KH560 can provide better modification efficiency than their counterparts and are able to enhance the freezing-thawing resistance and cracking resistance of cement stabilized macadams.