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The structural response of prisms of cross section 100×100 mm and length of 500 mm constructed with reinforced fibrous concrete and subjected to pure tensile loading has been presented in this contribution. The main focus was to study the effects of adding different metallic fibers in mono and hybrid form in the conventionally reinforced concrete on the tension stiffening and strain development. Two metallic fibers with different geometrical, mechanical and physical properties were investigated: amorphous metallic straight fibers and carbon steel hooked-end fibers. A total of four concrete mixtures: control, single fiber and hybrid fiber reinforced concretes were prepared. The fibers were investigated at content of 20 kg/m 3 for single fiber reinforced concretes, and for hybrid fiber reinforced concrete, at content of 40 kg/m 3 . Through studying load-deformation response of composites and strain development in steel bar and concrete, it has been found that the metallic fibers improve tension stiffening effect and influence significantly the strain development. The effect of two metallic fibers on tension stiffening was seen to be different at different loading stages. On the other hand, when fibers were used in hybrid form, the behaviour of the composite was improved at all loading stages in terms of tension stiffening and resistance to cracking.

The feasibility of carbonation curing of ternary blend Portland cement–metakaolin–limestone was investigated. Portland cement was substituted by the combination of metakaolin and limestone at levels of 15%, 30%, and 45% by the mass. The ternary blends were cured with four different combinations of ambient and carbonation curing. The mechanical property, CO2 uptake, and mineralogical variations of the ternary blend pastes were investigated by means of compressive strength test, thermogravimetric analysis, and X-ray diffractometry. In addition, volume of permeable voids and sorptivity of the ternary blends were also presented to provide a fundamental idea of the pore characteristics of the blends. The test results showed that the increasing amount of metakaolin and limestone enhanced the CO2 uptake, reaching 20.7% for the sample with a 45% cement replacement level at 27 d of carbonation. Meanwhile, the compressive strength of the samples was reduced up to 65% upon excessive incorporation of metakaolin and limestone. The samples with a replacement level of 15% exhibited a comparable strength and volume of permeable voids to those of the sample without substitution, proving that the ternary blend Portland cement–metakaolin–limestone can be a viable option toward the development of eco-friendly binders.

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