Search

A persistent rise in the costs of construction materials has led to the need to address this problem in line with the Sustainable Development Goals. This research employed vegetal soft and rigid fibers in a screed mortar to produce a sustainable fabric–cement matrix. Four different vegetal-dried fibers (hemp, flax, miscanthus, and bamboo) with dosages of 0.4, 0.6, 0.8, 1.2, 2, and 4 kg/m3 were used. Laboratory investigations were slump test, bulk density, air occluded, shrinkage, and mechanical strength. Scanning Electron Microscope (SEM) assessments were performed and analyzed on the natural fibers and the screed formulation. The results highlight that fiber dosages significantly influence the above-mentioned properties. [ABSTRACT FROM AUTHOR]

There is a need to develop new construction materials with improved mechanical performance and durability that are low-priced and have environmental benefits at the same time. This paper focuses on the rheological, mechanical, morphological, and durability properties of synthetic and steel fiber reinforced self-compacting concrete (SCC) containing 5–15% metakaolin (M) by mass as a green replacement for Portland cement. Testing of the fresh mixes included a slump-flow test, density, and porosity tests. Mechanical properties were determined through compression and flexural strength. A rapid chloride penetrability test (RCPT) and the chloride migration coefficient were used to assess the durability of the samples. A scanning electron microscope (SEM) with energy dispersion spectrometry (EDS) was used to study the concrete microstructure and the interfacial transition zone (ITZ). The results show that a combination of metakaolin and hybrid fibers has a negative effect on the flowability of SCC. In contrast, the inclusion of M and hybrid fibers has a positive effect on the compressive and flexural strength of SCC. The fracture of SCC samples without fibers was brittle and sudden, unlike the fiber-reinforced SCC samples, which could still transfer a considerable load with increasing crack mouth opening deflection. Overall, the chloride migration coefficients were reduced by up to 71% compared to the control mix. The chloride reduction is consistent with the resulting compact concrete microstructure, which exhibits a strong bond between fibers and the concrete matrix. [ABSTRACT FROM AUTHOR]