Study On The Application Of Waste Rubber Powder/Amorphous Poly Alpha Olefin Compound Modified Asphalt In Porous Asphalt Pavement

High viscosity modified asphalt,represented by TAFPACK-Super(TPS)modified asphalt,is widely used in porous asphalt(PA)pavement in China,but rubber modified asphalt is rarely used.Due to the good performance of waste tire rubber(WTR)and amorphous poly alpha olefin(APAO)compound modified asphalt and dense-graded asphalt mixture,this paper studies the feasibility of WTR/APAO compound modified asphalt used in PA mixtures.In this paper,the PA mixtures of two kinds of WTR/APAO modified asphalt(15%WTR+4%APAO,15%WTR+6%APAO)were selected as the research object,and compared with the PA mixture of TPS modified asphalt,WTR modified asphalt(15%WTR)and 70# base asphalt.Firstly,the mix proportion design of the above 5 kinds of PA mixtures were carried out.The mineral aggregate gradation was determined by 20% air voids(VV),and the best asphalt content(OAC)were determined by Cantabro abrasion test and draindown test.With APAO increase,the abrasion loss and draindown of WTR/APAO PA mixtures decreased.Compared with TPS PA mixture,WTR/APAO and WTR PA mixtures had bigger abrasion loss,bigger OAC and smaller draindown.Then,the road performance of 5 PA mixtures were studied in this paper.The test results showed that the addition of APAO significantly improved the high temperature performance,water resistance,fatigue life and durability of WTR/APAO PA mixtures,but reduced its low temperature crack resistance.15% WTR+6% APAO PA mixture had the best high temperature stability,water loss resistance,the longest fatigue life and excellent durability,but its low temperature crack resistance was poor.Finally,the mechanical and functional properties of 5 PA mixtures were studied.The test results showed that the addition of APAO improved the deformation resistance,elasticity and skid resistance of WTR/APAO PA mixtures.15%WTR+6%APAO PA mixture had the best resistance to deformation and excellent skid resistance.The permeability of WTR/APAO and WTR PA mixtures was poor compared with 70# PA mixture and TPS PA mixture,but it still met the requirements of specification CJJ/T 190-2012.In summary,15% WTR+6% APAO PA mixture had excellent high temperature performance,water resistance,aging,fatigue resistance,deformation resistance and skid resistance,its permeability were good,and its low temperature crack resistance was poor.Therefore,15%WTR+6%APAO compound modified asphalt can be used for PA pavement in non cold area.