Journal of Structural Engineering & Applied Mechanics (Online), vol.7, no.3, pp.198-218, 2024 (Peer-Reviewed Journal)
Although concrete has high compressive strength values, it has a heavy unit volume
and low tensile strength. In this study, the normal-weight aggregate, which takes up
the most space in concrete by volume and mass, was partially replaced with pumice
aggregate, and macro steel fiber (30 mm) was also added to the mixtures. This
experimental work aims to investigate the effect of pumice aggregate amount on the
fresh and hardened properties, as well as the flexural performance of the selfcompacting
lightweight concrete (SCLC). The replacement proportions of pumice
aggregate with crushed sand were arranged as 45%, 50%, and 55% of the entire
aggregate by weight. Three mixtures, each with 1% macro steel fiber reinforcement
and without fiber, were prepared for each mixture scenario. The mix design of these
six mixtures was arranged to achieve the self-compacting ability and the workability
tests recommended by EFNARC (slump-flow, T50, J-ring) were taken into account.
To investigate the mechanical properties (compressive, splitting tensile, and flexural
strengths) and flexural toughness of the samples, the specimens were cured in water
at 23±2 °C for 28 days. As a result, the unit volume weights of the specimens
produced from pumice-substituted mixtures decreased with the increase in the
pumice dosage, while the compressive, splitting tensile, and flexural strengths
decreased. However, it has been determined that all SCLC mixtures including
pumice aggregate provided workability properties in general and had enough
compressive strength to be used in the production of structural bearing elements,
regardless of fiber content. As a result, the optimum pumice aggregate replacement
percentage with crushed sand was found to be 45% and the best flexural performance
values of the specimens having macro steel fiber were observed in the ones having
45% pumice aggregate substitution.