Experimental investigation on mechanical performance of high-porous rubberized asphalt pavement grouted with ECC mortar

Open-graded porous asphalt (OGPA) pavement requires extensive maintenance. Need to consider the accumulation of dust, soil, and other debris in the cavities of this pavement. This research aims to develop alternative pavements whose ideas originate from the demerit of OGPA pavement. The pavements in question are high-porous asphalt pavement grouted with engineered cementitious composites (ECC) mortar (called HAGE) and high-porous rubberized asphalt pavement grouted with ECC mortar (referred to as HRGE). This study is the first demonstration of ECC-grouted high-porous rubberized asphalt. Fine aggregate is not used, resulting in an average porosity of 29–32% for the asphalt-crushed stone skeleton, and ECC mortar served as a suitable grouting material. The fresh ECC mortar mixtures have good workability, with the initial compressive strength exceeding 20 MPa at the age of 3 days; meanwhile, the asphalt-crushed stone skeletons exhibit very low compressive strengths of less than 0.75 MPa. But the average compressive strength of the HAGE specimens at 3, 7, and 28 days is 11.76, 14.28, and 21.31 MPa, respectively. Meantime, HRGE specimens have a compressive strength of 10.04, 11.84, and 17.51 MPa at 3, 7, and 28 days, respectively. Furthermore, HRGE specimens provide higher flexibility and durability properties than HAGE specimens. The elasticity and compressibility of the crumb rubber (CR) significantly influence the compressive strength, flexural strength, impact and fire resistance of HRGE specimens. In addition, ECC mortar can protect the asphalt-crushed stone skeleton from fire. It can withstand fire heat up to a temperature of 558.7 °C. This fire-resistance study is quite relevant to current road pavement conditions and is truly applicable. Many factors rise to require fire-resistant road pavements. urban heat caused by global warming, frequent car accidents leading to fires, fuel tanker fires in tunnels, etc.