Roller-compacted geopolymer concrete mixes with recycled asphalt pavement material

Abstract

The performance of roller compacted concrete (RCC) was greatly influenced by variations in material proportion, optimum moisture content, density of mixes and methodology adopted making it different from conventional concrete mixes. Even though RCC has gained popularity, the complex phenomenon involved in developing the RCC mixes limits it from large-scale applications. In this study, reclaimed asphalt pavement (RAP) incorporated roller-compacted geopolymer concrete (RGC) mixes were developed herein with different compaction techniques such as vibratory hammer (VH), modified proctor (MP), vibration table (VT) and compression machine (CM) are studied and compared with control mixes of natural aggregates. Initially, the effect of alkali solutions such as sodium hydroxide (SH) and sodium silicate (SS) on the physical properties. During, the second phase mechanical properties such as dry density, compressive, flexural and split-tensile strength, modulus of elasticity and microstructure properties will be investigated. The test results revealed that compaction efforts were greatly influenced by the alkali solution. Furthermore, the poor bond characteristics between RAP and the binder matrix had a significant effect on strength properties. Also, the various compaction techniques affected the mechanical properties of mixes developed herein. In Comparison with various compaction efforts, VH and MP produced comparable results, whereas the VT method underestimated and overestimated the various strength properties. Although, the CM method reports comparable results but difficult to maintain consistency in strength aspects. Therefore, optimization of various parameters influencing the concrete properties needs to be achieved for field density.