再生骨料沥青混合料最大理论密度计算方法研究

The study on calculation method of maximum theoretical density of recycled aggregates asphalt mixture

由于建筑垃圾再生骨料表面发育有密级的微裂缝和含有大量水泥砂浆等杂质的影响,导致强度偏低,压碎值、孔隙率、吸水率大、密度偏小。由此在沥青混合料的配合比设计时,难以用传统方法确定沥青混合料的最大理论密度。本文通过理论分析和试验验证提出适合于吸水率远大于2%(甚至超过4%)的建筑垃圾再生骨料的沥青混合料最大理论密度确定方法。文章通过检测建筑垃圾再生骨料的吸水率、毛体积密度、表观密度等基本性能指标,分析再生骨料与天然骨料之间的主要性质差别,基于SEM微观电镜扫描分析,分析其表面孔隙结构。通过试验研究发现,再生骨料的最大理论密度实测值要大于计算值,这和一般天然骨料试验结果规律不同。最终证明,采用最大理论密度反算求解的方法,能更准确的求出再生骨料沥青混合料的最大理论密度。

Because of the formation of micro cracks and the effect of impurities such as cement mortar,recycled aggregates was showed that it has more disadvantages such as low strength,high absorbing water rate,porosity and water absorption and small density. In mix proportion design of asphalt mixture,it was difficult to use traditional method to determine the theoretical maximum density of asphalt mixture. In this paper,the method of determining construction waste recycled aggregate asphalt mixture density suitable for high bibulous rate（ greater than 2%,even more than 4%） was put forward through theoretical analysis and experimental verification.Through the detection of water absorption,bulk density,apparent density of recycled aggregate of construction waste and other basic performance index,analyses the main differences of the characters between recycled aggregate and natural aggregate. Based on the analysis of SEM micro electron microscope scanning,its surface pore structure was analyzed.Through experimental research,found that recycled aggregates theoretical maximum density measured values than calculated value,this is different from general law of natural aggregate results. Finally,calculating maximum density by solving method was proved that can more accurately calculate the biggest theory of recycled aggregate asphalt mixture density.