What is emulsion? what are its advantages as a road pavement materials?
An emulsion is a mixture of heated bitumen and water which are unmixable in general. The mixing is done in the presence of an emulsifying agent like soap or resin. The emulsifying agent helps in mixing the two liquids. Depending upon the stability of the protective coating of emulsifying agent, the emulsion is classified in three category - Rapid setting - used for surface dressing Medium setting - suitable with coarse aggregate Slow setting - suitable with fine aggregate A bituminous emulsion contains 30% to 60%, by weight, of bitumen, 0.5 to 1% of emulsifying agent and the rest is water. Emulsion is commonly manufactured by Colloid mill method. Advantages of emulsion - It can be used when the aggregates are wet. Heating of aggregates and binder is not required and thus conserve energy. It can be used in cold weather. Emulsion is most ideal for patching and repair work. Due to low viscosity it can penetrate into fine cracks and hence useful for sealing cracks. Uses - Emulsion can