01626241

Component

Recycling of pavement materials has proven to be viable alternative for pavement construction and rehabilitation due to its economic and environmental benefits. In Egypt, large quantities of milled asphalt are produced daily most of which are unutilized. This paper investigates utilizing milled asphalt in construction of pavement subgrade/subbase layers. Blends of Reclaimed Asphalt Pavement (RAP) and sand soil with ratios of 10-90% RAP content were considered and laboratory tests were performed on these blends. Results indicated that California Bearing Ratio (CBR) value increases as RAP content increases up to 50-60%. The RAP-sand blend with 50% RAP content has superior results of gradation, maximum dry density, CBR value, and relative increase in CBR when RAP content increases by 10%. Blends were also stored for 0-14 days before soaking, and results showed increase in CBR after one-week storage. The optimum RAP-sand blend (50%/50%) was employed in Mechanistic-Empirical pavement design and analysis to assess the benefit of its use as subgrade or subbase layer, and its benefit was expressed as a reduction in required asphalt thickness for different values of equivalent single axle load (ESAL). Results showed that the blend is more effective when used as subbase than as subgrade. The recommended blend was also evaluated for its cost-effectiveness based on data of a rehabilitation project in Egypt. Results indicated that using RAP-sand blend to replace conventional subbase layer can save up to 70% of cost of conventional subbase layer, which is a good incentive for future consideration of this blend.

This paper was sponsored by TRB committee AFP70 Standing Committee on Aggregates. Alternate title: Viability Assessment of Using Reclaimed Asphalt Pavement-Sand Blend in Road Construction: A Case Study in Egypt.

01618707

17-06447

English

16p

2017

Transportation Research Board 96th Annual Meeting

Digital/other

Figures; References; Tables

Blends; California bearing ratio; Case studies; Cost effectiveness; Mechanistic-empirical pavement design; Reclaimed asphalt pavements; Rehabilitation; Sand; Subbase (Pavements); Subgrade (Pavements)

Egypt

Highways; Maintenance and Preservation; Materials; Pavements

Transportation Research Board Annual Meeting 2017 Paper #17-06447

TRIS, TRB, ATRI

Dec 8 2016 12:37PM