Bonding Evaluation of Asphalt Emulsions used as Tack Coats through Shear Testing.

Featured Application: Evaluation of bond strength between pavement layers. A poor bond between the layers constituting an asphalt pavement can cause structural problems such as slippage, delamination, and top-down cracking. These are consequences of the pavement being unable to act as a continuous element and to properly transmit the effects of the traffic to underlying layers. The aim of this research was to characterize an asphalt emulsion with low asphalt content using the Mexican standard and to evaluate its performance through the Laboratorio de Caminos de Barcelona (LCB) shear testing. Cationic slow setting (SS) and cationic rapid setting (RS) asphalt emulsions were tested by varying the asphalt contents, dosages, and cure times. The slow set emulsions presented a greater fracture energy than did the rapid set emulsions; a dose of 0.3 L/m² provided the same level of resistance as a 0.5 L/m² dose; and a 55% asphalt content provided greater resistance than the 60% asphalt content. [ABSTRACT FROM AUTHOR]