Cold Recycling Of Old Asphalt Pavement Material At The Grassroots Level

Each year, there are numerous asphalt pavements needing reconstructing. The old way to remove the old pavement and rebuild a new one will produce masses of waste materials. This will occupy vast expanses of land, contaminate surrounding areas, and result in an enormous waste of resources as well. The adoption of cold in-place recycling technology which could reutilize pavement materials is in accordance with the present trend toward sustainable development, and therefore is a burning issue lying before the researchers and engineers.Based on the research results from home and abroad, and the characteristic of the widely-adopted semi-rigid pavement, the thesis studies the cold in-place recycling technology stabilized by cement. And the thesis proposes the method of the mixture design of cold in-place recycling. The primary mechanical indexes of the recycled mixture are tested, including the unconfined compressive strength, the cleavage strength and the resilient modulus. The changing law of these indexes related to the cement content, the aged-period and the testing temperature is explored and the relationship between indexes is established. The pavement behavior and performance of designed mixture is studied and contrasted with the mixture which is recommended by the Technical Specifications for Construction of Highway Roadbases, including mechanical performance, stableness, anti-brushing performance, the anti-crack performance and fatigue performance. Moreover, the thesis delves on the construction craft and quality control of the cold in-place recycling technology. The recycled mixture is applied to the base and this is proven to meet the requirements of pavement performance.The thesis also draws a comparison between cold in-place recycling and rebuilding. And the results indicate that cold in-place recycling is a desirable mode in road mass-reconstruction, in particular in the regions lacking grit and pebbles.