Experimental testing of hot mix asphalt mixture made of recycled aggregates

Abstract

The migration of population towards big cities generates rapid construction activities. These activities not only put pressure on natural resources but also produce construction, renovation and demolition waste. There is an urgent need to find out ways to handle this waste owing to growing environmental concerns. This can reduce pressure on natural resources as well. This paper presents the results of experimental studies which were carried out on hot mix asphalt mixture samples. These samples were manufactured by adding recycled aggregates (RA) with natural crushed stone aggregates (CSA). Three levels of addition of RA were considered in the presented studies. RA were obtained from both the concrete waste of construction, renovation and demolition activities and reclaimed asphalt pavement. Separate samples were manufactured with the coarse and fine aggregate fractions of both types of RA. Samples made with CSA were used as control specimens. The samples were prepared and tested using the Marshall method. The performance of the samples was investigated in terms of density-void and stability/flow analysis and was compared with the performance criteria as given by National Highway Authority for wearing course material in Pakistan. Based on this data optimum asphalt contents were determined. All the samples made by adding up to 50% RA conform to the specification requirements of wearing course material as given by National Highway Authority in terms of optimum asphalt contents, voids in mineral aggregates and stability/flow. A statistical analysis of variation of these samples confirmed that addition is also possible statistically.

Effect of bitumen grade on hot asphalt mixes properties prepared using recycled coarse concrete aggregate

“…The use of RCA reduced the voids filled with bitumen. Such trend was also observed by some researchers [20][21][22][23][24] in the voids filled with bitumen, which could be attributed to its lower viscosity when compared to 60/70 bitumen. Fig.…”

“…It can be observed that increasing RCA percent led to increase in the value of the optimal binder content. Such observation is reported by Rafi et al [20]. Rafi et al [20] attributed this increase to the higher absorption of the RCA compared with that of the normal aggregate.…”

“…Such observation is reported by Rafi et al [20]. Rafi et al [20] attributed this increase to the higher absorption of the RCA compared with that of the normal aggregate. Similarly, Sushanta et al [21] observed significant increase in the binder content when RCA is used.…”

“…Some of these researches are included in references [19][20][21][22][23][24][25][26]. Most of these researches consider that the use of RCA is environmentally efficient.…”

Evaluation of Mechanical Properties of Recycled Material for Utilization in Asphalt Mixtures

“…Therefore, the idea of using recycled material in pavement construction has attracted the attention of many researchers (e.g., Karlsson Chandh and Akhila, 2016) in the pavement industry to investigate feasibility of the application of some of waste materials as alternative material in pavement construction [1][2][3][4][5][6][7][8].…”