Application of Pull-off Test for Evaluating Bond Strength Properties of Modified Bitumen Emulsions

Reduced adhesion between aggregate particles and bitumen binders, and reduced cohesion within the bitumen of mixes, will result in stripping and segregation distresses. These distresses will ultimately result in pothole formation and other distresses in pavements. For repairing these distresses, major maintenance works will be required, including reconstruction of the pavement. In this research, with the aim of determination of adhesion and cohesion properties between aggregate particles and bitumen binders, pull off testing method was adopted. Samples were consisted of two cationic bitumen emulsions of rapid and medium breaking types that were also modified with a latex liquid rubber. Aggregates were consisted of two different types of granite and dolomite origin. Their mineralogy was determined, carrying out XRF testing and analysis. In performing the research the role of parameters such as curing time and curing temperature were also investigated. Testing results showed that modification of the bitumen emulsions with the application of 3% latex provided increased adhesion properties and increased durability between bitumen emulsion and the aggregate particles. It was also shown that the interaction between aggregate particles and the bitumen emulsions were great. Comparing behavior of the two aggregate types, it was concluded that the dolomite aggregates provided better adhesion properties. In addition, it resulted that the role of curing time and temperature were dominant in providing adequate adhesion between bitumen and aggregate particles. The increase was more dominant in samples containing latex modified binders.