Materials and Structures

, Volume 49, Issue 11, pp 4765–4778 | Cite as

Characterization of superabsorbent poly(sodium-acrylate acrylamide) hydrogels and influence of chemical structure on internally cured mortar

Original Article


Internal curing of mortar through superabsorbent polymer hydrogels is explored as a solution to self-desiccation. Four different hydrogels of poly(sodium-acrylate acrylamide) are synthesized and the impact of chemical composition on mortar is assessed with relative humidity and autogenous shrinkage testing. The hydrogels are characterized with swelling tests in different salt solutions and compression tests. Chemical composition affected both swelling kinetics and gel network size. Mortar containing these hydrogels had increased relative humidity and markedly reduced autogenous shrinkage. Additionally, the chemical structure of the hydrogels was found to significantly impact the mortar’s shrinkage. Hydrogels that quickly released most of their absorbed fluid were able to better reduce autogenous shrinkage compared to hydrogels that retained fluid for longer periods (>4 h), although this performance was highly sensitive to total water content. The release of absorbed water in hydrogels is most likely a function of both Laplace pressure of emptying voids and chemically-linked osmotic pressure developing from an ion concentration gradient between the hydrogels and cement pore solution. If the osmotic pressure is strong enough, the hydrogels can disperse most of the absorbed water before the depercolation of capillary porosity occurs, allowing the water to permeate the bulk of the mortar microstructure and most effectively reduce self-desiccation and autogenous shrinkage.


Internal curing Superabsorbent polymer Ion-hydrogel interactions Autogenous shrinkage Relative humidity 

Supplementary material

11527_2016_823_MOESM1_ESM.doc (2.4 mb)
(DOC 2456 kb)


  1. 1.
    Annual Water Quality Report. Indiana American Water. Available at Accessed 11 Jan 2016
  2. 2.
    Perlman H. Water Hardness, The USGS Water Science School. Available at Accessed 20 Jan 2016
  3. 3.
    ASTM C150–12 (2012) Standard specification for Portland Cement. ASTM International, West ConshohockenGoogle Scholar
  4. 4.
    ASTM C305–14 (2012) Standard practice for mechanical mixing of hydraulic cement pastes and mortars of plastic consistency. ASTM International, West ConshohockenGoogle Scholar
  5. 5.
    ASTM E104–02 (2012) Standard practice for maintaining constant relative humidity by means of aqueous solutions. ASTM International, West ConshohockenGoogle Scholar
  6. 6.
    ASTM C1698–09 (2014) Standard test method for autogenous strain of cement paste and mortar. ASTM International, West ConshohockenGoogle Scholar
  7. 7.
    Bentur A, Igarashi S, Kovler K (2001) Prevention of autogenous shrinkage in high-strength concrete by internal curing using wet lightweight aggregates. Cem Concr Res 31:1587–1591CrossRefGoogle Scholar
  8. 8.
    Bentz DP, Lura P, Roberts JW (2005) Mixture proportioning for internal curing. Concr Int 27:35–40Google Scholar
  9. 9.
    Bentz DP, Snyder DA (1999) Protected paste volume in concrete: extension to internal curing using saturated lightweight fine aggregate. Cem Concr Res 29:1863–1867CrossRefGoogle Scholar
  10. 10.
    Brouwers HJH (2012) Paste models for hydrating calcium sulfates, using the approach by Powers and Brownyard. Constr Build Mater 36:1044–1047CrossRefGoogle Scholar
  11. 11.
    Browning J, Darwin D, Reynolds D, Pendergrass B (2011) Lightweight aggregate as internal curing agent to limit concrete shrinkage. ACI Mater J 108:638–644Google Scholar
  12. 12.
    Çaykara T, İnam R (2003) Determination of average molecular weight between crosslinks and polymer-solvent interaction parameters of poly(acrylamide-g-ethylene diamine tetraacetic acid) polyelectrolyte hydrogels. J Appl Polym Sci 91:2168–2175CrossRefGoogle Scholar
  13. 13.
    Flory PJ (1992) Swelling of network structures. In: Principles of polymer chemistry, 15th edn. Cornell University Press, New York, pp 576–581Google Scholar
  14. 14.
    Friedrich S (2012) Superabsorbent polymers (SAP). In: Mechtcherine V, Reinhardt H (eds) Application of superabsorbent polymers (SAP) in concrete construction, 1st edn. RILEM, pp 13–19. doi:10.1007/978-94-007-2733-5_3
  15. 15.
    Habert G, Arribe D, Dehove T, Espinasse L, Le Roy R (2012) Reducing environmental impact by increasing the strength of concrete: quantification of the improvement to concrete bridges. J Clean Prod 35:250–262CrossRefGoogle Scholar
  16. 16.
    Hasholt TM, Jensen OM (2015) Chloride migration in concrete with superabsorbent polymers. Cem Concr Compos 55:290–297CrossRefGoogle Scholar
  17. 17.
    Işık B, Kıs M (2004) Preparation and determination of swelling behavior of poly(acrylamide-co-acrylic acid) hydrogels in water. J Appl Polym Sci 94:1526–1531CrossRefGoogle Scholar
  18. 18.
    Jensen OM, Hansen PF (2001) Water-entrained cement-based materials I. Principles and theoretical background. Cem Concr Res 31:647–654CrossRefGoogle Scholar
  19. 19.
    Jensen OM, Hansen PF (2002) Water-entrained cement-based materials II. Experimental observations. Cem Concr Res 32:973–978CrossRefGoogle Scholar
  20. 20.
    Jensen OM, Lura P (2006) Techniques and materials for internal water curing of concrete. Mater Struct 39:817–825CrossRefGoogle Scholar
  21. 21.
    Kabiri K, Mirzadeh H, Zohuriaan-Mehr MJ (2008) Undesirable effects of heating on hydrogels. J Appl Polym Sci 110:3420–3430CrossRefGoogle Scholar
  22. 22.
    Kong X, Zhang Z, Lu Z (2014) Effect of pre-soaked superabsorbent polymer on shrinkage of high-strength concrete. Mater Struct. doi:10.1617/s11527-014-0351-2
  23. 23.
    Mehta PK, Monteiro PJM (2014) Permeability. In: Concrete: microstructure, properties, and materials, 4th edn. McGraw-Hill Education, New YorkGoogle Scholar
  24. 24.
    Miller A (2014) Using a centrifuge for quality control of pre-wetted lightweight aggregate in internally cured concrete. Dissertation, Purdue UniversityGoogle Scholar
  25. 25.
    Peppas LB, Peppas NA (1988) Structural analysis of charged polymeric networks. Polym Bull 20:285–289Google Scholar
  26. 26.
    Peppas LB, Peppas NA (1991) Equilibrium swelling behavior of pH-sensitive hydrogels. Chem Eng Sci 46:715–722CrossRefGoogle Scholar
  27. 27.
    Qavi S, Pourmahdian S, Eslami H (2014) Acrylamide hydrogels preparation via free radical crosslinking copolymerization: kinetic study and morphological investigation. J Macromol Sci A 51:842–848CrossRefGoogle Scholar
  28. 28.
    Rajabipour F, Sant G, Weiss J (2008) Interactions between shrinkage reducing admistures (SRA) and cement paste’s pore solution. Cem Concr Res 38:606–615CrossRefGoogle Scholar
  29. 29.
    Rubinstein M, Colby RH (2003) Networks and gels. In: Polymer physics. Oxford University Press, New York, pp 274–281Google Scholar
  30. 30.
    Rodríguez de Sensale G, Goncalves AF (2014) Effects of fine LWA and SAP as internal water curing agents. Int J Concr Struct Mater 8:229–238CrossRefGoogle Scholar
  31. 31.
    Rüchel R, Steere LJ, Erbe EF (1978) Transmission-electron microscope observations of freeze-etched polyacrylamide gels. J Chromatogr 166:563–575CrossRefGoogle Scholar
  32. 32.
    Schroefl C, Mechtcherine V, Vontobel P, Hovind J, Lehmann E (2015) Sorption kinetics of superabsorbent polymers (SAPs) in fresh Portland cement-based pastes visualized and quantified by neutron radiography and correlated to the progress of cement hydration. Cem Concr Res 75:1–13CrossRefGoogle Scholar
  33. 33.
    Schröfl C, Mechtcherine V, Gorges M (2012) Relation between the molecular structure and the efficiency of superabsorbent polymers (SAP) as concrete admixture to mitigate autogenous shrinkage. Cem Concr Res 42:865–873CrossRefGoogle Scholar
  34. 34.
    Volkov AG, Paula S, Deamer DW (1997) Two mechanisms of permeation of small neutral molecules and hydrated ions across phospholipid bilayers. Bioelectrochem Bioener 42:153–160CrossRefGoogle Scholar
  35. 35.
    Walraven J (2009) High performance concrete: a material with a large potential. J Adv Concr Technol 7:145–156CrossRefGoogle Scholar
  36. 36.
    Weber S, Reinhardt HW (1997) A new generation of high performance concrete: concrete with autogenous curing. Adv Cem Based Mater 6:59–68CrossRefGoogle Scholar
  37. 37.
    Weiss J, Lura P, Rajabipour F, Sant G (2008) Performance of shrinkage-reducing admixtures at different humidities and at early ages. ACI Mater J 105:478–486Google Scholar
  38. 38.
    Wypych G (2003) Knovel solvents: a properties database. ChemTech Publishing. Accessed 1 Dec 2015
  39. 39.
    Zhu Q, Barney CW, Erk KA (2015) Effect of ionic crosslinking on the swelling and mechanical response of model superabsorbent polymer hydrogels for internally cured concrete. Mater Struct 48:2261–2276CrossRefGoogle Scholar

Copyright information

© RILEM 2016

Authors and Affiliations

  1. 1.School of Materials EngineeringPurdue UniversityWest LafayetteUSA

Personalised recommendations