HP Bitumen Handbook - Hindustan Petroleum Corporation Limited
HP Bitumen Handbook - Hindustan Petroleum Corporation Limited
HP Bitumen Handbook - Hindustan Petroleum Corporation Limited
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4. Properties of bitumen<br />
4.2 Adhesion Properties of <strong>Bitumen</strong><br />
<strong>Bitumen</strong> has excellent<br />
adhesive qualities provided<br />
the conditions are<br />
favourable. However in<br />
presence of water the<br />
adhesion does create some<br />
problems. Most of the<br />
aggregates used in road<br />
construction possess a weak<br />
negative charge on the surface. The bitumen aggregate bond is because of a<br />
weak dispersion force. Water is highly polar and hence it gets strongly attached<br />
to the aggregate displacing the bituminous coating.<br />
The factors influencing aggregate bitumen adhesion are plenty and some of the<br />
factors influencing this property are as below:<br />
4.2.1 External: Rainfall, Humidity, Water pH, Presence of salts, Temperature,<br />
Temperature cycle, Traffic, Design, Workmanship, Drainage<br />
4.2.2 Aggregate: Mineralogy, Surface texture, Porosity, Dirt, Durability, Surface<br />
area, Absorption, Moisture content, Shape, Weathering<br />
4.2.3 <strong>Bitumen</strong>: Rheology, Constitution<br />
4.2.4 Mix: Void content, Permeability, <strong>Bitumen</strong> content, <strong>Bitumen</strong> film<br />
thickness, Filler type, Aggregate grading, Mix type.<br />
The above list is only indicative and not exhaustive.<br />
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