Strength development of Recycled Asphalt Pavement - fly ash geopolymer as a road construction material

Abstract This paper investigates the strength development of Recycled Asphalt Pavement (RAP)-Fly Ash (FA) geopolymer as a road construction material. A mixture of sodium hydroxide solution (NaOH) and sodium silicate solution (Na2SiO3) is used as a liquid alkaline activator (L). Unconfined Compression Strength (UCS) is used as an indicator to measure the strength development of RAP-FA geopolymer and RAP-FA blend (without L). The UCS development is analyzed via Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD) analyses. Test results show that the compacted RAP-FA blend can be used as a base course material as its UCS values meet the specified strength requirements. The UCS of RAP-FA blends increases with time due to the formation of Calcium Silicate Hydrate (C-S-H) and Calcium Aluminate Hydrate (C-A-H), as detected from XRD and SEM analyses. The UCS of RAP-FA geopolymer increases as the NaOH/Na2SiO3 ratio decreases and is higher than those of compacted RAP-FA blends. When the NaOH/Na2SiO3 ratios are less than 90:10. At an early stage of 7 days and room temperature curing, XRD and SEM analyses indicate that low geopolymerization products (N-A-S-H) in RAP-FA geopolymer are detected when only NaOH (NaOH/Na2SiO3 = 100:0) is used as L, hence the UCS of RAP-FA geopolymer at NaOH/Na2SiO3 = 100:0 is lower than that of RAP-FA blends. With increasing curing time and temperature, NaOH solution dissolves more silica and alumina from FA in the geopolymerization reaction, hence the UCS developed with time and temperature. The highly soluble silica from Na2SiO3 incorporates with leached silica and alumina from FA into a N-A-S-H gel which co-exists with C-S-H and C-A-H from RAP and FA reaction. Therefore, the 7-day UCS values of RAP-FA geopolymer increase with decreasing NaOH/Na2SiO3 ratios for both room temperature and 40 °C curing. This research study confirms the potential of RAP-FA blends and RAP-FA geopolymers as an alternative stabilized pavement material.

[1]  M. W. Bo,et al.  Stabilization of Demolition Materials for Pavement Base/Subbase Applications Using Fly Ash and Slag Geopolymers: Laboratory Investigation , 2016 .

[2]  P. Chindaprasirt,et al.  Comparative study on the characteristics of fly ash and bottom ash geopolymers. , 2009, Waste management.

[3]  J. Davidovits.  Global warming impact on the cement and aggregates industries , 1994 .

[4]  V. Sirivivatnanon,et al.  Workability and strength of coarse high calcium fly ash geopolymer , 2007 .

[5]  S. Horpibulsuk,et al.  STRENGTH ASSESSMENT OF CEMENT TREATED SOIL- RECLAIMED ASPHALT PAVEMENT (RAP) MIXTURE , 2014 .

[6]  P. Duxson,et al.  Effect of Alkali Cations on Aluminum Incorporation in Geopolymeric Gels , 2005 .

[7]  W. H. Chesner,et al.  USER GUIDELINES FOR WASTE AND BY-PRODUCT MATERIALS IN PAVEMENT CONSTRUCTION , 1998 .

[8]  A. Arulrajah,et al.  Durability against Wetting–Drying Cycles of Water Treatment Sludge–Fly Ash Geopolymer and Water Treatment Sludge–Cement and Silty Clay–Cement Systems , 2016 .

[9]  Stephanie Glendinning,et al.  Effect of calcium content on soil stabilisation with alkaline activation , 2012 .

[10]  Anand J. Puppala,et al.  Resilient Moduli Response of Moderately Cement-Treated Reclaimed Asphalt Pavement Aggregates , 2011 .

[11]  Arul Arulrajah,et al.  Compressive strength development in fly ash geopolymer masonry units manufactured from water treatment sludge , 2015 .

[12]  Nenad Gucunski,et al.  Recycled Asphalt Pavement as a Base and Sub-Base Material , 1997 .

[13]  J. Davidovits.  Geopolymers : inorganic polymeric new materials , 1991 .

[14]  Tanakorn Phoo-ngernkham,et al.  Influence of curing conditions on properties of high calcium fly ash geopolymer containing Portland , 2014 .

[15]  P J Cosentino,et al.  DEVELOPING SPECIFICATIONS FOR USING RECYCLED ASPHALT PAVEMENT AS BASE, SUBBASE OR GENERAL FILL MATERIALS, PHASE II , 2001 .

[16]  P. Chindaprasirt,et al.  Sulfate Resistance of Clay-Portland Cement and Clay High-Calcium Fly Ash Geopolymer , 2015 .

[17]  Warren A. Dick,et al.  Alkali-activated complex binders from class C fly ash and Ca-containing admixtures. , 2010, Journal of hazardous materials.

[18]  Sireesh Saride,et al.  Utilization of Reclaimed Asphalt Pavements in Indian Low-Volume Roads , 2016 .

[19]  Ramzi Taha,et al.  Evaluation of Cement Kiln Dust-Stabilized Reclaimed Asphalt Pavement Aggregate Systems in Road Bases , 2003 .

[20]  Á. Palomo,et al.  Nanostructure/microstructure of fly ash geopolymers , 2009 .

[21]  A. Al-Harthy,et al.  Cement Stabilization of Reclaimed Asphalt Pavement Aggregate for Road Bases and Subbases , 2002 .

[22]  J. Davidovits.  PROPERTIES OF GEOPOLYMER CEMENTS , 1994 .

[23]  J.S.J. van Deventer,et al.  Effect of the Alkali Metal Activator on the Properties of Fly Ash-Based Geopolymers , 1999 .

[24]  Ángel Palomo,et al.  Alkali activation of fly ash: Effect of the SiO2/Na2O ratio Part I: FTIR study , 2007 .

[25]  J. Deventer,et al.  Statistical Thermodynamic Model for Si/Al Ordering in Amorphous Aluminosilicates , 2005 .

[26]  Robert Locander,et al.  Analysis of Using Reclaimed Ashpalt Pavement (RAP) as a Base Course Material , 2009 .

[27]  Arul Arulrajah,et al.  Calcium carbide residue: Alkaline activator for clay–fly ash geopolymer , 2014 .

[28]  Prinya Chindaprasirt,et al.  Influence of NaOH solution on the synthesis of fly ash geopolymer , 2009 .

[29]  S. Shen,et al.  Factors influencing strength development in clay–fly ash geopolymer , 2013 .

[30]  Chai Jaturapitakkul,et al.  NaOH-activated ground fly ash geopolymer cured at ambient temperature , 2011 .

[31]  Suksun Horpibulsuk,et al.  Strength development in clay–fly ash geopolymer , 2013 .

[32]  Arul Arulrajah,et al.  Reclaimed Asphalt Pavement and Recycled Concrete Aggregate Blends in Pavement Subbases: Laboratory and Field Evaluation , 2014 .

[33]  Joseph Davidovits,et al.  GEOPOLYMERS: Man-Made Rock Geosynthesis and the Resulting Development of Very Early High Strength Cement , 1994 .

[34]  Guoping Zhang,et al.  Synthesis, Characterization, and Mechanical Properties of Red Mud–Based Geopolymers , 2010 .

[35]  Arul Arulrajah,et al.  Suitability of recycled construction and demolition aggregates as alternative pipe backfilling materials , 2014 .

[36]  Sireesh Saride,et al.  Evaluation of Fly-Ash-Treated Reclaimed Asphalt Pavement for the Design of Sustainable Pavement Bases: An Indian Perspective , 2014 .

[37]  Shigemitsu Hatanaka,et al.  The effect of adding nano-SiO2 and nano-Al2O3 on properties of high calcium fly ash geopolymer cured , 2014 .

[38]  Ángel Palomo,et al.  Alkali-activated fly ashes: A cement for the future , 1999 .

[39]  Á. Palomo,et al.  Microstructure Development of Alkali-Activated Fly Ash Cement: A Descriptive Model , 2005 .

[40]  Arul Arulrajah,et al.  Evaluation of Interface Shear Strength Properties of Geogrid-Reinforced Construction and Demolition Materials Using a Modified Large-Scale Direct Shear Testing Apparatus , 2014 .

[41]  Prinya Chindaprasirt,et al.  Effects of NaOH concentrations on physical and electrical properties of high calcium fly ash geopolymer paste , 2014 .

[42]  Joseph Davidovits,et al.  Environmentally Driven Geopolymer Cement Applications. , 2002 .

[43]  Elie Y. Hajj,et al.  Evaluation of the Use of Reclaimed Asphalt Pavement in Airfield HMA Pavements , 2010 .

[44]  Ramzi Taha,et al.  Evaluation of Reclaimed Asphalt Pavement Aggregate in Road Bases and Subbases , 1999 .

[45]  Anand J. Puppala,et al.  Characterization of Cement-Fiber-Treated Reclaimed Asphalt Pavement Aggregates: Preliminary Investigation , 2011 .

[46]  Sireesh Saride,et al.  Sustainable Reuse of Limestone Quarry Fines and RAP in Pavement Base/Subbase Layers , 2012 .