Development of A Special Emulsion for Pavement Recycling

摘要

A quick strength and very slow setting bitumen emulsion, which is suitable to cold-in-place pavement recycling, has been formulated through double-liquidating and double-emulsifying technique. Laboratory tests and field trials have been carried out to evaluate the formulated emulsion, and some conclusions might be made as follows: a) The developed emulsion has a satisfactory setting time for coating aggregates properly during mixing and being very workable during handling. b) The patched potholes in small-scale trials and recycled pavements in full-scale trial can be opened to very heavy traffic without any damage even immediate raining after compaction. This means that developed emulsion has a very high initial strength to bind aggregates. c) Results from laboratory tests have showed that cold mixes with developed emulsion have satisfactory early-stage strength, Marshall stability about 10 kN and resilient modulus about 3000 Mpa for rich mixes (emulsion content 8%), Marshall stability about 5 kN, resilient modulus about 7000 Mpa, and indirect tensile strength about 0.28 N/mm2 for lean mixes (emulsion content 4%). d) The small-scale trials have shown perfect conditions after experiencing about 8-month actions of heavy traffic and weather. It can be expected from this result that cold mixes with developed emulsion have satisfactory ultimate (final) strength.