Methods of modifying the brittle behavior of cementitious composites

Abstract

We put forward effective methods of increasing the tensile strain of cementitious composites with 2% PVA fiber and high fly ash content. The test results show that curing condition has a significantly effect on the tensile performance. It is approved that the specimens incorporated appropriate volume fraction rubber powder and lightweight aggregate greatly increase the tensile strain of composites at medium-term age, but indefinitely at long-term age. To a certain extent, EVA can limitedly enhance the tensile performance of comentitious composites owing to the formation of polymer membrane and the hindered hydration of cement.

Keywords

high-ductility cementitious composites (HDCC) / tensile properties / high content of fly ash / rubber powder / light aggregate / ethylene vinyl alcohol latex powder

References

[1] Li V. C., Leung C. K. Y. Steady-state and Multiple Cracking of Short Random Fiber Composites[J]. Journal of Engineering Mechanics, 1992, 118(11): 2 246-2 264.

[2] Leung C. K. Y., Li V. C. Effect of Fiber Inclination on Crack Bridging Stress in Fiber Reinforced Brittle Matrix Composites[J]. Journal of Mechanical Physics, 1992, 40(6): 1 333-1 362.

[3] Li V. C., Wu H. C. Conditions for Pseudo Strain-Hardening in Fiber Reinforced Brittle Matrix Composites[J]. Applied Mechanics Revolution, 1992, 45(8): 390-398.

[4] Li V. C., Mishra D. K., Wu H. C. Matrix Design for Pseudo-Strain-Hardening Fiber Reinforced Cementitious Composites[J]. Materials and Structures, 1995, 28: 586-595.

[5] Kanda T., Li V. C. Member of ASCE New Micromechanics Design Theory for Pseudostrain Hardness Cementitious Composite[J]. Journal of Engineering Mechanics, 1999, 125(4): 373-381.

[6] Li V. C., Wang S., Wu C. Tensile Strain-Hardening Behavior or Polyvinyl Alcohol Engineered Cementitious Composite (PVA-ECC)[J]. ACI Materials Journal, 2001, 98(6): 483-492.

[7] Maeshall D. B., Cox B. N., Evans A. G. The Mechanics of Matrix Cracking in Brittle Matrix Fiber Composites[J]. ACTA Metallurgical, 1985, 33(11): 2 013-2 021.

[8] Wang S., Li V. C. Tailoring of Pre-Existing Flaw in ECC Matrix for Saturated Strain Hardening[C]. Proceedings of the Fifth International Conference on Fracture Mechanics of Concrete and Concrete Structures, 2004 Colorado Ia-FraMCos 1 005-1 012.

[9] Li V. C., Wu H. C., Chan Y. W. Interfacial Property Tailoring for Pseudo Strain-Hardening Cementitious Composites[C]. Advanced Technology on Design and Fabrication of Composite Materials and Structures, 1995 Netherlands Kluwer Acad. Publ. 261-268.

[10] Sun W., Mandel J. A. SAID Samir Studies of the Properties of the Fiber-Matrix Interface in Steel Fiber Reinforced Mortar[J]. ACI Materials Journal, 1987, 84(12): 101-109.

[11] Akers S. A. S. Long Term Durability of PVA Reinforcing Fibers in a Cement Matrix[J]. The International Journal of Cement Composite and Lightweight Concrete, 1989, 11: 79-91.

[12] Kanda T., Li V. C. Interface Property and Apparent Strength of High-Strength Hydrophilic Fiber in Cement Matrix[J]. Journal of Materials in Civil Engineering, 1998, 10(1): 5-13.

[13] LI V C and WANG S. Process for Increasing the Ductility of High Performance Fiber-Reinforced Brittle Matrix Composites and Composites Produced Thereby[P]. US Patent 7169224. 2007-01-30

[14] Redon C. Measuring and Modifying Interface Properties of PVA Fibers in ECC Matrix[J]. ASCE J. Materials in Civil Engineering, 2001, 13(6): 399-406.

[15] Chen H., Sun W., Piet S. Interfacial Transition Zone Between Aggregate and Paste in Cementitious Composites (II): Mechanism of Formation and Degradation of Interfacial Transition Zone Microstructure and Its Influence Factors[J]. Journal of the Cement Ceramic Society, 2004, 32(1): 70-80.

[16] Chan Y. W., Li V. C. Age Effect on the Characteristics of Fibre/Cement Interfacial Properties[J]. Journal of Materials Science, 1997, 32: 5 287-5 292.

[17] Wang S., Li V. C. Engineered Cementitious Composites with High-Volume Fly Ash[J]. ACI Materials Journal, 2007, 104(3): 233-241.