Interlayer Treatment And Evaluation For Asphalt Pavement Of Concrete Bridge Deck

SBS modified asphalt and rubber modified asphalt are mostly used in the traditional waterproof bonding layer,but the pavement diseases caused by poor bonding between layers occur from time to time.Based on previous st udies,WTR(Waste Tire Rubber)/APAO(Amorphous Poly Al Pha Olefin)composite modified asphalt is a high viscosity and high elastic modified asphalt with good high and low temperature performance and anti-aging properties.Therefore,WTR/APAO composite modified asphalt is applied to waterproof adhesive layer and feasibility is explored.15%WTR+4%APAO composite modified asphalt with better performance is selected as the research object to explore its interlayer bonding performance,and compared with SBS modified asphalt and crumb rubber modified asphalt(15%WTR).Firstly,the displacement of asphalt concrete surface and the shear bond between asphalt concrete and asphalt concrete are compared.The results show that the optimum amount of SBS modified asphalt,WTR modified asphalt and WTR/APAO composite modified asphalt is 1.7kg/m~2,1.2kg/m~2 and 1.2kg/m~2 respectively when the structure depth is 0.880mm and the gravel coverage is 70%.At this time,the WTR/APAO composite modified asphalt has the highest shear strength and pull-out strength,the best interlayer bonding performance,and the minimum displacem ent when the specimen is damaged.Secondly,through water penetration test,direct shear test and pull-out test under different temperatures and before and after immersion,freeze-thaw and aging,the water resistance,temperature sensitivity,water loss re sistance and aging resistance of three kinds of waterproof adhesive layer are studied,and the material cost of three kinds of asphalt is calculated and compared.The results show that three kinds of asphalt waterproof bonding layers have good impermeabili ty;temperature has a great influence on the interlayer bonding performance,and WTR/APAO composite modified asphalt has the least temperature effect and the least temperature sensitivity;WTR/APAO modified asphalt has the worst water loss resistance,but its shear strength and pull-out strength after immersion and freeze-thaw are still higher than SBS modified asphalt and WTR modified asphalt;3 When the asphalt is used as the waterproof bonding layer,it shows better aging resistance.The WTR/APAO composi te modified asphalt has the lowest cost.To sum up,the WTR/APAO waterproof bonding layer has good interlaminar bonding properties,low temperature sensitivity,good waterproof and anti-aging properties,and poor water resistance.However,after water dam age,it has the best interlaminar bonding property,and its economy is the best.Therefore,WTR/APAO composite modified asphalt is suitable for waterproof bonding layer.