Cement mortar with enhanced flexural strength and durability-related properties using in situ polymerized interpenetration network

Abstract

The low flexural strength and high brittleness of cementitious materials impair their service life in building structures. In this study, we developed a new polymer-modified mortar by in situ polymerization of acrylamide (AM) monomers during the cement setting, which enhanced the flexural and durable performances of mortars. The mechanical properties, micro-and-pore structures, hydrated products, interactions between cement hydrates and polyacrylamide (PAM), and durability-related properties of the mortars were investigated comprehensively. Mortars with 5% PAM exhibited the best performance in terms of flexural strength among all the mixtures. The mechanical strength of cement pastes modified by in situ polymerization of AM monomers was significantly superior to those modified by PAM. The chemical interactions between the polymer molecules and cement hydrates together with the formation of polymer films glued the cement hydrates and polymers and resulted in an interpenetrating network structure, which strengthened the flexural strength. Reductions in porosity and calcium hydroxide content and improvement in capillary water absorption were achieved with the addition of PAM. Finally, the chloride resistance was significantly enhanced with the incorporation of PAM.

Keywords

acrylamide / in situ polymerization / interaction / porosity / durability

References

[1] Mohammadi Y, Carkon-Azad R, Singh S P, Kaushik S K. Impact resistance of steel fibrous concrete containing fibres of mixed aspect ratio. Construction & Building Materials, 2009, 23(1): 183–189

[2] Li J, Zhang Y X. Evolution and calibration of a numerical model for modelling of hybrid-fibre ECC panels under high-velocity impact. Composite Structures, 2011, 93(11): 2714–2722

[3] Ding Y, Li D, Zhang Y, Azevedo C. Experimental investigation on the composite effect of steel rebars and macro fibers on the impact behavior of high performance self-compacting concrete. Construction & Building Materials, 2017, 136: 495–505

[4] Soufeiani L, Raman S N, Jumaat M Z B, Alengaram U J, Ghadyani G, Mendis P. Influences of the volume fraction and shape of steel fibers on fiber-reinforced concrete subjected to dynamic loading–A review. Engineering Structures, 2016, 124: 405–417

[5] Chen X, Zhu G, Zhou M, Wang J, Chen Q. Effect of organic polymers on the properties of slag-based geopolymers. Construction & Building Materials, 2018, 167: 216–224

[6] Brooks W E. Polypropylene Fiber-Reinforced Microsilica Concrete Bridge Deck Overlay at Link River Bridge, Experimental Features Project 98–01. Oregon: Oregon Department of Transportation, 2000

[7] Gagnç R. Reinforced concrete bridge deck repair using a thin bonded overlay: Results from the Cosmos bridge experimental repair. In: International RILEM TC 193-RLS Workshop on Bonded Concrete Overlays. Stockholm: RILEM Publications SARL, 2004, 67–82

[8] Agavriloaie L, Oprea S, Barbuta M, Luca F. Characterisation of polymer concrete with epoxy polyurethane acryl matrix. Construction & Building Materials, 2012, 37: 190–196

[9] Ribeiro M S S, Gonçalves A F, Branco F A B. Styrene-butadiene polymer action on compressive and tensile strengths of cement mortars. Materials and Structures, 2008, 41(7): 1263–1273

[10] Liu Q, Liang R, Li Z J, Guo S Y, Sun G X. Mechanical strong and durable cement mortars reinforced by controlling the polymer phase size. Materials Research Express, 2019, 6(7): 075203

[11] Lidmila M, Tesárek P, Plachy T, Prošek Z, Nežerka V, Topič J. Composite material based on cement and PVA: Evolution of mechanical properties during first 28 days. Advanced Materials Research, 2014, 1054: 215–220

[12] Yaowarat T, Horpibulsuk S, Arulrajah A, Mirzababaei M, A Rashid A S. Compressive and flexural strength of polyvinyl alcohol-modified pavement concrete using recycled concrete aggregates. Journal of Materials in Civil Engineering, 2018, 30(4): 04018046

[13] Papaioannou S, Argyropoulou R, Kalogiannidou C, Melidis G, Papadopoulou L, Evelzaman I, Argyropoulou M. Mechanical and adhesion properties of polymer-modified cement mortars in relation with their microstructure. Journal of Adhesion, 2019, 95(2): 126–145

[14] Liu Q, Liu W, Li Z J, Guo S J, Sun G X. Ultra-lightweight cement composites with excellent flexural strength, thermal insulation and water resistance achieved by establishing interpenetrating network. Construction & Building Materials, 2020, 250: 118923

[15] Joo M K, Lho B C. Evaluation of properties of polymer-modified mortar with CSA. Journal of the Korea Institute for Structural Maintenance and Inspection, 2015, 19(1): 35–44

[16] Li L, Wang R, Lu Q. Influence of polymer latex on the setting time, mechanical properties and durability of calcium sulfoaluminate cement mortar. Construction & Building Materials, 2018, 169: 911–922

[17] Bansal P P, Sidhu R. Mechanical and durability properties of fluoropolymer modified cement mortar. Structural Engineering and Mechanics, 2017, 63(3): 317–327

[18] Monteny J, De Belie N, Vincke E, Verstraete W, Taerwe L. Chemical and microbiological tests to simulate sulfuric acid corrosion of polymer-modified concrete. Cement and Concrete Research, 2001, 31(9): 1359–1365

[19] ASTM D790–10. Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials. West Conshohocken, PA: ASTM International, 2010

[20] Sun Z, Xu Q. Micromechanical analysis of polyacrylamide-modified concrete for improving strengths. Materials Science and Engineering A, 2008, 490(1–2): 181–192

[21] Yan R. Water Soluble Macromolecular. Beijing: Chemistry Industry Press, 2003, 86–87

[22] Schulze J. Influence of water-cement ratio and cement content on the properties of polymer-modified mortars. Cement and Concrete Research, 1999, 29(6): 909–915

[23] Wang R, Wang P M, Li X G. Physical and mechanical properties of styrene–butadiene rubber emulsion modified cement mortars. Cement and Concrete Research, 2005, 35(5): 900–906

[24] Lu Z, Zhou X, Zhang J. Study on the performance of a new type of water-repellent admixture for cement mortar. Cement and Concrete Research, 2004, 34(11): 2015–2019

[25] Rai U S, Singh R K. Effect of polyacrylamide on the different properties of cement and mortar. Materials Science and Engineering A, 2005, 392(1–2): 42–50

Acknowledgements

This work was funded by the Science and Technology Development Fund, Macao SAR (No. 0083/2018/A2); Multi-Year Research Grant (No. MYRG2018-00164-IAPME) and Research & Development Grant for Chair Professor (No. CPG2020-00002-IAPME)from the University of Macao.

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