Micro-Mechanical Properties of Individual Phases in Cement Pastes under Brine Solution Using Nanoindentation and Scanning Electron Microscopy

Abstract:

Understanding the micro-mechanical properties and the microstructure of cement-based materials under the saline lake environment in western China can provide a scientific basis for the durability design. In this study, cement pastes ((w/c=0.35) and (w/c=0.53)) were prepared and soaked in brine solution to carry out the dry-wet cycle test, the chemical composition of which is similar to saline lake solution. The micrographs of corroded regions and corrosion products were observed and analyzed under scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). Micro-mechanical properties of different phases were tested by nanoindentation, and multi-peaks fitting was carried out for the experimental frequency distributions of the indentation modulus and indentation hardness by Gaussian function. In the meantime,the statistical distribution of micro-mechanical properties was summarized for the hydrates in corroded cement paste, which has included the low density calcium–silicate–hydrates (LD C-S-H gel), high density calcium–silicate–hydrates (HD C-S-H gel) and calcium hydroxide (CH). The results show that micro mechanical properties of each phase in cement paste after brine corrosion decreased significantly. In addition, the water-cement ratio has little effect on the micro mechanical properties, but much effect on volume fraction of each phase.

• Periodical: Journal of Nano Research (Volume 46)
• Pages: 31-44
• DOI: https://doi.org/10.4028/www.scientific.net/JNanoR.46.31
• Online since: March 2017
• Authors: Yue Li, Wang Peng*, Zhong Zheng Guan, Qing Jun Ding
• Keywords: Brine Corrosion, Dry-Wet Cycle, Micro Mechanical Properties, Nanoindentation, SEM

References

[1] Acker P, Micromechanical analysis of creep and shrinkage mechanisms. Creep, Shrinkage and Durability Mechanics of Concrete and Other Quasi-Brittle Materials, Oxford, UK, (2001) 15-25.

DOI: 10.1061/9780784413111.026

[2] Velez K, Maximilien S, Damodot D, et al, Determination by nanoindentation of elastic modulus and hardness of pure constituents of Portland cement clinker, Cem. Concr. Res. 31(4) (2001) 555–561.

DOI: 10.1016/s0008-8846(00)00505-6

[3] Jennings HM, Thomas JJ, Gevrenov JS, et al, A multi-technique investigation of the nanoporosityof cement paste, Cem. Concr. Res. 37(3) (2007) 329–336.

DOI: 10.1016/j.cemconres.2006.03.021

[4] Jennings HM, Thomas JJ, Gevrenov JS, et al, Nanostructure of C-S-H gel in cement paste as a function of curing conditions and relative humidity, International Conference on Creep, Shrinkage and Durability of Concrete and Concrete Structures, Nantes, France, (2005).

[5] Wu Y, Li H, Kang L, Characterization of calcium silicate hydrate gel using nanoindentation technique, J. Build. Mater. 13(3) (2010) 277-280.

[6] Zhu W, Hughes JJ, Bicanic N, et al, Nanoindentation mapping of mechanical properties of cement paste and natural rocks, Mater. Charact. 58(11) (2007) 1189-1198.

DOI: 10.1016/j.matchar.2007.05.018

[7] Constantindes G, Ulm FJ, The nanogranular nature of C–S–H, J. Mech. Phys. Solids. 55(1) (2007) 64–90.

[8] Constantindes G, Ulm FJ, Vliet KV, On the use of nanoindentation for cementitious materials, Mate. Struct. 36 (2003) 191-196.

[9] Heukamp FH, Ulm FJ, Germaine JT, Mechanical properties of calcium-leached cement pastes: triaxial stress states and the influence of the pore pressures, Cem. Concr. Res. 31(5) (2001) 767-774.

DOI: 10.1016/s0008-8846(01)00472-0

[10] Ulm FJ, Vandamme M, Jennings HM, et al, Does microstruc-ture matter for statistical nanoindentation techniques? Cem. Concr. Compos. 32(1) (2010) 92–99.

[11] Vandamme M, Ulm FJ, Fonollosa P, Nanogranular packing of C–S–H at substochiometric conditions, Cem. Concr. Res. 40(1) (2010) 14–26.

DOI: 10.1016/j.cemconres.2009.09.017

[12] Plassard C, Lesniewska E, Pochard I, et al, Intrinsic elatic properties of calcium silicate hydrates by nanoindentation, Proceeding with peer review, Montreal, Canada (2007).

[13] Qingxin Z, Wei S, Keren Z et al, Comparison for elastic modulus of cement, ground granulated blast-furnace slag and fly ash particles. Journal of the Chinese Ceramic Society 33(7) (2005) 837-841.

[14] Keren Z, Wei S, Wei L et al, Effects of blast furnace slag on micro-mechanical properties of interface transition zone, J. Nanjing. U. Aeronaut. Astronautics. 40(3) (2008) 407—411.

[15] Jiande H, Ganghua P, Wei S, Elastic modulus change investigation of cement paste before and after carbonation using nanoindentation technique, Chinese Materials Conference Abstracts (2011).

DOI: 10.1016/j.proeng.2011.12.461

[16] Oliver WC, Pharr GM, An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments, Mater. Res. 7(6) (1992) 1564–1583.

DOI: 10.1557/jmr.1992.1564

[17] Oliver WC, Pharr GM, Measurement of hardness and elastic modulus by instrumented indentation: Advances in understanding and refinements to methodology, Mater. Res. 19(1) (2004) 3–20.

DOI: 10.1557/jmr.2004.19.1.3

[18] Taihua Z, Micro/nano mechanical test technology and its application, China. Machine. Press. Beijing (2004).

[19] Richardson IG, Tobermorite/jennite and tobermorite/calcium hydroxide-based models for the structure of C–S–H: applicability to hardened pastes of tricalcium silicate, b-dicalcium silicate, Portland cement, and blends of portland cement with blast-furnace slag meta-kaolin or silica fume, Cem. Concr. Res. 34(9) (2004).

DOI: 10.1016/j.cemconres.2004.05.034

[20] Trtik P, Munch B, Lura P, A critical examination of nanoindentation on model materials and hardened cement pastes based on virtual experiments, Cem. Concr. Compos. 31 (2009) 705–714.

DOI: 10.1016/j.cemconcomp.2009.07.001

[21] Wang XH, Jacobsen S, He JY, Application of nanoindentation testing to study of the interfacial transition zone in steel fiber reinforced mortar, Cem. Concr. Res. 39(8) (2009) 701–715.

DOI: 10.1016/j.cemconres.2009.05.002

[22] Nemecek J, Šmilauer V, Kopecky L, Characterization of alkali-Activated fly-ash by nanoindentation Bittnar Z, Bartos P J M, Nemecek J, et al. Nanotechnology in construction 3: Proceedings of the NICOM3. Berlin Heidelberg: Springer, (2009).

DOI: 10.1007/978-3-642-00980-8_45

[23] Chen JJ, Sorelli L, Vandamme M, et al, A coupled nanoindentation/SEM-EDX study on low water/cement ratio Portland cement paste: Evidence for C–S–H/CH nanocomposites, J. Am. Ceram. Soc. 93(5) (2010) 1484–1493.

DOI: 10.1111/j.1551-2916.2009.03599.x

[24] Al-Amoudi OSB, Attack on plain and blended cements exposed to aggressive sulfate environments, Cem. Concr. Compos. 24(3-4) (2002) 305-316.

DOI: 10.1016/s0958-9465(01)00082-8

[25] Dejong MJ, ULM FJ, The nanogranular behavior of C-S-H at elevated temperatures (up to 700 °C), Cem. Concr. Res. 37(1) (2007) 1-12.

[26] Mondal P, Shah SP, Marks LD, A reliable technique to determine the local mechanical properties at the nanoscale for cementitious materials, Cem. Concr. Res. 37(1) (2007) 1440-1444.

DOI: 10.1016/j.cemconres.2007.07.001

[27] Beaudoin J, Comparison of mechanical paoperties of compacted calcium hydroxide and Portland cement paste systems, Cem. Concr. Res. 13(3) (1983) 319-324.

DOI: 10.1016/0008-8846(83)90030-3

[28] Monteiro PJM, Chang CT, The elastic-modulus of calcium hydroxide, Cem. and. Concr. Res. 25(8) (1995) 1605-1609.

[29] Jennings HM, Thomas JJ, Gevrenov JS, et al, A multi-technique investigation of the nanoporosity of cement paste, Cem. Concr. Res. (37) (2007) 329-336.

DOI: 10.1016/j.cemconres.2006.03.021

[30] Delesse M, Procédé mécanique pour déterminer la composition des roches, C. R. Acad. Sci. (Paris) (25) (1847) 544.