ARE LABORATORY CONDITIONS REPRESENTATIVE OF FIELD CONDITIONS? – A CLOSER LOOK AT GRAIN CRUSHING

摘要

Laboratory testing of granular materials is used to recommend pavement constructionrnguidelines such as layer thickness and water content. The validity of this approach has never beenrnquestioned. This study investigated if laboratory conditions are representative of field conditions byrnexamining construction practices and comparing them to laboratory testing practices. Grain sizerndistributions of aggregate samples compacted in the laboratory; in a simulated field condition and in arnfield application were found to be different. Grain crushing is identified as a factor that has beenrnoverlooked by previous studies and the differences observed in gradations with the compactionrntechniques tested might explain some of the discrepancies observed between design predictions andrnactual road service life spans.