Properties of Ultra-High Performance Concrete Using Optimization of Traditional Aggregates and Pozzolans
Construction and Building Materials
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The properties of ultra-high performance concretes (UHPCs) made with traditional fine aggregates, different cementitious materials types and combinations, and varying steel fiber contents and shapes were studied. In the first phase, a total of 78 UHPCs were used to assess their compressive and splitting-tensile strengths, and drying shrinkage, which led to identifying 40 optimized mixtures for the second phase of the investigation for which their compressive, splitting-tensile, and flexural strength, modulus of elasticity, load–deflection response, and drying shrinkage properties were obtained. The outcome of this study revealed that the optimized UHPCs displayed excellent bulk properties and dimensional stability. Amongst the utilized cementitious materials combinations, UHPCs made with the combined silica fume and class F fly ash, as a partial replacement of cement, performed the best, whereas the companion mixtures incorporating only class F fly ash exhibited the contrary. A clear strain hardening and softening was observed in the load–deflection response of steel fiber-reinforced UHPCs. Due to better steel to concrete surface adhesion, straight steel fibers had a more positive influence on the mechanical properties and dimensional stability of the studied UHPCs when compared to those of the hooked fibers. Overall, this experimental study supports that, with proper gradations and proportioning, traditional fine aggregates can be used as an effective substitute for the expensive filler materials used for production of the proprietary UHPCs without compromising their mechanical properties and dimensional stability.
Bulk properties; Cementitious materials; Conventional fine aggregate; Drying shrinkage; Steel fiber; Ultra-high performance concrete
Construction Engineering and Management
Properties of Ultra-High Performance Concrete Using Optimization of Traditional Aggregates and Pozzolans.
Construction and Building Materials, 299