Recycled asphalt pavement _ fly ash geopolymer as a sustainable stabilized pavement material

International Conference on Informatics, Technology and Engineering 2017

计算机科学

Horpibulsuk, S.^1 ; Hoy, M.^2 ; Witchayaphong, P.^3 ; Rachan, R.^4 ; Arulrajah, A.^5

School of Civil Engineering, Center of Excellence in Innovation for Sustainable Infrastructure Development, Suranaree University of Technology, Thailand^1

School of Civil Engineering, Suranaree University of Technology, Thailand^2

Center of Excellence in Innovation for Sustainable Infrastructure Development, Suranaree University of Technology, Thailand^3

Department of Civil Engineering, Mahanakorn University of Technology, Thailand^4

Department of Civil and Construction Engineering, Swinburne University of Technology, Australia^5

关键词: International standards;    Leachability of heavy metals;    Microstructural changes;    Recycled asphalt pavement;    Stabilized pavement materials;    Sustainable pavements;    Toxicity characteristic leaching procedures;    Unconfined compression strength;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/245/1/012005/pdf
DOI  :  10.1088/1757-899X/245/1/012005

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

Strength, durability, microstructure and leachate characteristics of Recycled Asphalt Pavement and Fly Ash (RAP-FA) geopolymers and RAP-FA blends as a sustainable pavement material are evaluated in this paper. The strength development of the stabilized materials with and without effect wetting-drying (w-d) cycles was determined by Unconfined Compression Strength (UCS) test. The mineralogical and microstructural changes of the stabilized material were analyzed by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The leachability of the heavy metals were measured by Toxicity Characteristic Leaching Procedure (TCLP) and compared with international standard. The results show that both RAP-FA blend and RAP-FA geopolymer increase with increasing the number of w-d cycles (C), reaching its peak at 6 w-d cycles. The XRD and SEM analyses indicate that the strength development of RAP-FA blend occurs due to stimulation of the chemical reaction between the high amount to Calcium in RAP and the high amount of Silica and Alumina in FA leaching to production of Calcium Aluminium (Silicate) Hydrate, while the geopolymerization reaction is observed in RAP-FA geopolymer. For C> 6, the significant macro- and micro-cracks developed during w-d cycles cause strength reduction for both RAP-FA blend and geopolymer. The TCLP results demonstrate that there is no environmental risk for these stabilized materials. Furthermore, FA-geopolymer can reduce the leachability of heavy metal in RAP-FA blend. The outcome from this research confirms the viability of using RAP-FA blend and RAP-FA geopolymer as alternative sustainable pavement materials.