study on the compaction effect factors of lime-treated loess highway embankments

this paper presents a study to investigate the effects of water content, lime content and compaction energy on the compaction characteristics of lime-treated loess highway embankments. laboratory compaction tests were conducted to determine the maximum dry density 𝜌_{𝑑𝑚𝑎𝑥} and optimum water content 𝑤_𝑜𝑝𝑡 of loess with different lime contents (0, 3, 5 and 8%), and to examine the effects of water content, lime content and compaction energy on the value of 𝜌_{𝑑𝑚𝑎𝑥} and 𝑤_𝑜𝑝𝑡. in situ compaction tests were performed to obtain the in situ dry density 𝜌_{𝑖𝑛−𝑠𝑖𝑡𝑢} and the degree of compaction 𝐾 of different lime-treated loess. experimental embankments with different fill materials (0, 3, 5 and 8% lime treated loess) were compacted by different rollers during in situ tests. the results indicate that 𝜌𝑑 increases due to the increase of water content w. once water content exceeds 𝑤_𝑜𝑝𝑡, dry density 𝜌_𝑑 decreases dramatically. the addition of lime induced the increase of 𝑤𝑜𝑝𝑡 and the decrease of 𝜌_{𝑑𝑚𝑎𝑥}. a higher compaction energy results in a higher value of 𝜌_{𝑑𝑚𝑎𝑥} and a lower value of 𝑤_𝑜𝑝𝑡. the value of 𝜌_{𝑖𝑛−𝑠𝑖𝑡𝑢} achieves it’s maximum value when in situ water content 𝑤_{𝑖𝑛−𝑠𝑖𝑡𝑢} was larger than the value of 𝑤𝑜𝑝𝑡 (+1-2%). the degree of compaction 𝐾 can hardly be achieved to 100% in the field construction of embankments. higher water content and compaction energy is needed for optimum compaction.