石灰粉煤灰微粘结级配碎石路用性能研究

为提高级配碎石的回弹模量和抗剪切强度,降低沥青路面的疲劳开裂的可能性,提高其抗车辙能力,在无粘结级配碎石中掺加适量的二灰结合料,形成微粘结碎石,使其同时具有半刚性基层和级配碎石基层的优点.试验结果表明二灰的加入可以提高级配碎石的和易性,当填充系数在0.9～1.1之间时,压实系数提高5%,28 d龄期的回弹模量达700 MPa,塑性变形可降低60%,渗透系数满足排水性能要求;二灰微粘结级配碎石的二灰最佳外掺量为5.0%～7.0%之间,二灰:碎石的比例范围在4.5:95.5～6.5:93.5之间,二灰的配比宜采用石灰:粉煤灰=1:4.

Study on Pavement Performance of Lime-flyash Micro-bonded Graded Aggregates

In order to enhance resilient modulus and shear strength of graded aggregate, reduce the fatigue cracking probability and improve the ability of rut resistance, the suitable amount of lime-flyash was mixed in unbounded grading macadam to form a micro-bonded graded aggregates which has the advantages of semi-rigid base and unbounded grading aggregate base.Experimental result shows that (1) filling some lime-flyash can improve the level of workability of graded aggregates, when filling coefficient is between 0.9 and 1.1, the compaction coefficient increases by 5% , resilient modulus in the age of 28 days reaches 700 Mpa, plastic deformation reduces by 60%, permeability coefficient meets the drainage requirements; (2) the best ash content of lime-flyash micro-bonded graded aggregate is 5.0%～7.0%, the proportion of lime-flyash and gravel is in the range of 4.5:95.5～6.5:93.5; and (3) the proportion of lime and flyash should be 1:4.