Compressive strength development and microstructure of cement-asphalt mortar

Abstract

The compressive strength developing process and the microstructure of cement-asphalt mortar (CA mortar) were investigated. The fluidity of CA mortar has a great influence on its strength. The optimum value of spread diameter of slump flow test is in the range of 300 to 400 mm. The compressive strength of CA mortar keeps a relatively high growth rate in 56 days and grows slowly afterwards. The residual water of hydration in CA mortar freezes under minus environmental temperature which can lead to a significant reduction of the strength of CA mortar. Increasing A/C retards asphalt emulsion splitting and thus prolongs the setting process of CA mortar. The hydration products of cement form the major structural framework of hardened CA mortar and asphalt is a weak phase in the framework but improves the viscoelastic behavior of CA mortar. Therefore, asphalt emulsion should be used as much as possible on the condition that essential performance criterions of CA mortar are satisfied.

Keywords

asphalt emulsion / compressive strength / CA mortar / microstructure

References

[1] Esveld C. Recent Development in Slab Track [J]. Eur. Railw. Rev., 2003, 2: 81-85.

[2] Esveld C. Slab Track: A Competitive Solution [J]. Railw. Int., 1999, 6: 32-46.

[3] Koyama Y. Railway Construction in Japan [J]. Jpn. Railw. Transp. Rev., 1997, 12: 36-41.

[4] Wang F. Z., Liu Z. C., Wang T., . A Novel Method to Evaluate the Setting Process of Cement and Asphalt Emulsion in CA Mortar [J]. Mater. Struct., 2008, 41(4): 643-647.

[5] Kazuyosi O., Yosio I. Compressive Strength of the CA mortar and Its Temperature Susceptiblity[J]. Mem. Facul. Tech., 1976, 10(2): 1-13.

[6] Zhao D. T., Wang T. C., Liu X. Y., . Configuration and Performance of CA Mortar for Ballastless Slab Track [J]. J. Tianjing. Univ., 2008, 41(7): 793-799.

[7] J Q Zuo, Q B Jiang, B F Cai. Experimental Study on Emulsified Asphalt for CA Mortar Used in Slab Track [J]. Railw. Constr. Tech., 2005, (2):68–70 (in Chinese)

[8] Jin S. H., Chen X. F., Yang J. Key Technologies of CA Mortar for Slab Track [J]. China Railw. Sci., 2006, 27(2): 20-24.

[9] J Q Zuo, Q B Jiang, D Z Fu. Research of Cement Asphalt Mortar Elastic Cushion for Slab Track [J]. Railw. Eng., 2005 (9):96–98 (in Chinese)

[10] Wang F. Z., Wang T., Hu S. G. Rheological Behavior of Cement Asphalt Mortar [J]. Eng. J. Wuhan. Univ., 2008, 41(4): 69-72.