Investigation of the Effect of Recycled Asphalt Pavement Material on Permeability and Bearing Capacity in the Base Layer

Abstract

e purpose of this research was to investigate the effects of recycled asphalt pavement (RAP) and cement content on the permeability and bearing capacity characteristics of aggregate base courses. Mixtures containing untreated RAP ranging between 0 and 100 percent and 1, 2, and 3% cement-treated RAP were subjected to laboratory tests (bitumen content, sieve analysis, modified proctor, soaked California bearing ratio (CBR), and constant-level permeability tests). e results showed that, as the RAP percentage in the mixture increased, CBR values decreased considerably. Moreover, there is a linear increase in the CBR values with cement treatment. Optimum moisture contents (OMC) and maximum dry densities (MDD) showed a decreasing trend. Increasing the cement percentages in 100% RAP blend increases the OMC and MDD values. e permeability of RAP showed a decrease as the percentage of RAP and cement increased in blends. e study showed that the CBR value of the 20% RAP blend is also obtained in the 100% RAP/3% cement-treated blend. us, it has been understood that cement is a suitable material in order to increase the use of RAP. In addition, the increase in the percentage of RAP and cement made the base course more impermeable.

Assessment of the Sub-Base Material for the Optimum Moisture Content and Maximum Dry Density Using Amalgamated Pond Ash with Reclaimed Asphalt on Road Pavement

“…When the quantity of RAP in the recycled hot bituminous mix is 20% or less, the viscosity grade of bitumen should be the same as specified in Table 1. If the quantity of RAP in the mixture ranges from 20 to 35% (Seferoğlu et al, 2018). The viscosity grade of the virgin bitumen should be one grade softer than the grade generally specified for a 100% virgin mix.…”

Evolution of dynamic flow behavior in asphalt mixtures exposed to freeze-thaw cycles

“…However, in previous analysis, the quantitative measurements in microscale moisture distribution within samples were difficult to perform. That hindered the discussions on the macroscale permeability [2,[32][33][34][35]. The micro-scale seepage characteristics, mainly include local seepage velocity and wetting front position.…”

Estimation of Soil‐Water Characteristic Curve for Cohesive Soils with Methylene Blue Value

“…A correlation equation is observed between PI and MBV, as shown in (3). Witczak et al [22,23] suggested subjective criteria for goodness predictions based on the coefficient of determination (R 2 ) values. An excellent fit can be defined as R 2 ≥ 0.9, a good fit covers the R 2 range of 0.7-0.89, and a fair fit is defined as 0.4 ≤ R 2 ≤ 0.69. erefore, (3) is a good fit for selected cohesive soils and can provide a relatively satisfactory correlation.…”