Document Type : Research Paper

Authors

1 Civil Engineering Department , Geotechnical , University of technology, Baghdad, Iraq.

2 Civil Engineering Dept., University of Technology-Iraq, Alsina’a street,10066 Baghdad, Iraq.

Abstract

Pozzolime is a promising alternative binder, compared to Portland cement because of its low CO2 emission. it is produced by mixing hydrated lime, silica fume, and fly ash. Fiber is added to concrete to improve the durability, mechanical properties of the structure, and others. In this study, high-strength Pozzolime concrete was reinforced with hooked-end steel fiber which was added as fractions of volume of 0.5, 1, 1.5, and 2%. Optimization for fiber content was performed according to the workability and strength of the fiber-reinforced mixture. Obtained results showed that the compressive strengths at 14d and 90d increased by 71.4% and 58.3% respectively when adding 1.5% steel fiber. Correspondingly, the 14d, 28d, and 90d flexural strength of pozzolime concrete increased by 170.4%, 203.2%, and 191.4% respectively at 1.5% and a further increase in fiber content caused a reduction in strength. The finding presented in this research confirmed that the volume fraction (1.5%) can be considered as the optimum content.

Highlights

  • In UHPC, autogenous shrinkage dominates over the drying shrinkage.
  • High pouring temperature and coarse sand increase the number and size of pores.
  • Increasing silica fume over 25% of cement content reduces compressive strength.
  • Adding steel or basalt fibers minimize the inverse effect of autogenous shrinkage.

Keywords

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