水泥对泡沫沥青冷再生混合料水稳定性的影响

Effect of Portland Cement on Water Stability of Foam Asphalt Cold In-Place Recycled Mixture

通过对众泰AH—70沥青进行发泡试验,确定泡沫沥青发泡特性的影响因素和沥青的最佳发泡温度及用水量;通过泡沫沥青冷再生混合料配合比设计及水稳定性试验,表明水泥的掺加可明显改善泡沫沥青混合料的水稳定性,确定出此混合料最佳配合比和泡沫沥青混合料最佳水泥掺量在1%~2%之间;通过数字显微镜测试和SEM测试,分析了水泥提高泡沫沥青混合料强度的机理,表明泡沫沥青混合料中水泥水化后的水化产物形成空间网状结构,将集料颗粒包裹起来,是水泥增强混合料强度和水稳定性的主要原因。此研究可为泡沫沥青冷再生混合料设计中水泥掺量规范的制定提供参考。

Through foaming experiment of Zhongtai AH-70 asphalt,the best foaming temperature,water consumption and influencing factors of foamed asphalt′s foaming features are determined.By designing the mixt-ure proportion of foam asphalt cold in-place recycled mixture combined with the water stability experiment,it is found that the addition of cement can obviously improve foam asphalt mixture′s water stability,the best mixture proportion of foamed asphalt cold in-place recycled mixture is also confirmed and the best cement admixture is between 1%~2%.Using digital imaging microscope and SEM technology,it analyzes the mechanism of increasing intensity of foam asphalt mixture resulted by the addition of cement.It reveals that the cement hydration products contained in the foam asphalt mixture hydrolyzed into space mesh structure and wrapped up the aggregate particle,which is the main reason of that the cement can enhance the mixture′s intensity as well as the water stability.This research provides reference for cement admixture′s formulation in the designing of foam asphalt cold in-place recycled mixture.