Performance of Composite Modified Asphalt with Trinidad Lake Asphalt used as Waterproofing Material for Bridge Deck Pavement

Abstract Performance of composite modified asphalt with Trinidad Lake Asphalt (TLA) used as waterproofing material for bridge deck pavement was studied through the shear test, pull-out test, and water permeability test. The results showed that shear strength at 20°C of composite modified asphalt with TLA was affected by the material dosage and the optimum dosage was 1.2 kg/m2. Shear strength at 20°C of composite modified asphalt with TLA increased with the increase of TLA content and then decreased with the further increase of TLA content. However, the shear strength at 50°C shows different results. Based on shear strength at 20°C, the optimum TLA content was 20 % by total weight of composite modified asphalt. Bond strength at 20°C of composite modified asphalt with TLA was very close to that of styrene-butadiene-styrene (SBS) modified asphalt but the bond strength at 50°C of composite-modified asphalt with TLA was 47 % higher than that of SBS modified asphalt. Both composite modified asphalts with TLA and with SBS modified asphalt met the impermeability requirement. Composite modified asphalt with TLA could be used as waterproofing material for bridge deck pavement for better performance.