复掺膨胀剂和减缩剂水泥稳定碎石路用性能研究

Research on Road Performance of Cement Stabilized Macadam Mixed with Expansive Agent and Shrinkage Reducing Agent

为研究复掺膨胀剂和减缩剂水泥稳定碎石的路用性能,通过室内试验分析了复掺膨胀剂和减缩剂对水泥稳定碎石力学性能和干缩性能的影响。结果表明:复掺膨胀剂和减缩剂后,水泥稳定碎石试件的无侧限抗压强度、劈裂强度和劈裂回弹模量等指标均有所提高;随着膨胀剂掺量增加,减缩剂掺量减少,试件强度先增大后减小;掺外加剂抑制了试件劈裂回弹模量的后期增长,膨胀剂掺量增加,减缩剂掺量减少,该抑制作用增强。在实际工程中,复掺外加剂可通过减少膨胀剂掺量、增加减缩剂掺量提高水泥稳定碎石劈裂回弹模量的后期增长;复掺外加剂有助于改善水泥稳定碎石的干缩抗裂性能,且初期的改善效果更好;复掺膨胀剂和减缩剂存在最佳掺量,本试验条件下最佳掺量为复掺6%膨胀剂和2%减缩剂。

To study the anti cracking performance of cement stabilized macadam mixed with expansive agent and shrinkage reducing agent,the influence of expansive agent and shrinkage reducing agent on mechanical properties and dry shrinkage performance of cement stabilized macadam was studied and analyzed through laboratory tests.The results show that the unconfined compressive strength,splitting strength and splitting modulus of resilience are improved.With the increase of expansion agent content and the decreases of shrinkage reducing agent content,the strength index of the specimens increase firstly and then decrease.The later growth of the splitting resilient modulus is inhibited by the addition of additives,and the inhibition effect is enhanced by increasing the expansion agent and reducing the shrinkage reducing agent.On the contrary,the later growth of splitting modulus of resilience can be improved by reducing the expansion agent and increasing the shrinkage reducing agent in engineering.The addition of admixtures can improve the dry shrinkage and crack resistance of cement stabilized macadam,and the initial improvement effect is better.There is anoptimal conten in the ratio of expansive agent and shrinkage reducing agent,which is the specimen mixed with 6%expansion agent and 2%shrinkage reducing agent.