Cold Recycling

T h e D epartm ent of Highways has a ttem p ted only two cold recycl­ ing projects. T he first was constructed in 1978 on SR-32 in F oun ta in C ounty. T he road was reh ab ilita ted w ith an in-place stabilized base using an em ulsified asphalt. T h e pavem ent was ripped with a dozer, w indrow ed, and crushed in p lace. V irgin aggregate, 150 lb ./sq . yd., was added an d 2 .3% AE-150 was applied w ith a d istribu to r. T h e m aterials were m ixed in place w ith a ro tary m ixer. T he stabilized m ate ria l was leveled to a un iform cross section w ith a g rad er an d com pacted . A bitum inous coated coarse aggregate base was p laced over this and a seal coat was added for a w earing course. From all the in form ation I have, the project was a success. T he roadw ay was reh ab ilita ted w ith a m in im um of expense an d provides satisfactory service for the traffic loads it carries. T h e second project was constructed this past sum m er. T he im ­ petus cam e from some groundw ork laborato ry investigations conducted at P u rdue on the use of foam ed asphalt in recycled pavem ent layers. As an extension of this work the D epartm en t of Highways selected a secon­ dary road scheduled for resurfacing du rin g 1981 for a cold recycling project to com pare field perfo rm ance w ith the laborato ry results. R ehabilita tion of the road was divided into two experim ents. T he east h a lf of the project consisted of a recycled base using em ulsified asphalt and the west h a lf a recycled base using foam ed asphalt. Details of the em ulsion stabilized base follow. T he five m ain objectives of this p ro ject were to: