Research on self-healing concrete has flourished in recent years. This paper aims to comprehensively understand the current research situation and future development directions of self-healing concrete. It summarizes and analyzes the publications on self-healing concrete from 1974 to 2021 to reveal the current key research topics and development trends and identifies the most productive research constitutes. The bibliometric analysis software Biblioshiny was used to analyze 1433 documents written by 2961 authors and published in 450 sources retrieved from Scopus. The analysis included an overview of the leading information and an analysis of the authors, countries, universities/institution, publications, and keywords. Results obtained from the author analysis suggest that tracking the work of the most productive authors is essential, as it will provide researchers with valuable information, such as possible leads and ideas for future research work and collaboration opportunities. Countries, universities/institutes, and publications analysis revealed that more collaboration leads to more exposure and a higher citation rate, significantly promoting self-healing research development. A keywords analysis highlighted the focus areas in self-healing concrete and presented potential gaps in the literature. The findings of this study will provide scholars with a comprehensive understanding of the current research work in the field of self-healing concrete and its future directions. Results can also benefit stakeholders in making effective decisions to direct the development of the self-healing industry.

This study examines the fresh and hardened properties of normal- and high-strength concrete (NSC and HSC) reinforced with basalt macro-fibers (BMF) at a volume fraction (ν_f) of 0.5–1.5%. Workability tests were conducted on the fresh concrete to evaluate the slump, compacting factor, and vebe time. Mechanical tests were performed on the hardened concrete to examine the compressive strength, tensile properties, and flexural performance. Different durability characteristic tests were carried out to evaluate the water/chloride penetrability, bulk resistivity, and abrasion resistance of the hardened concrete. The addition of BMF reduced the concrete workability of both NSC and HSC at almost the same rate. A maximum slump reduction of 78%, on average, was recorded at ν_f of 1.5%. The compressive strength of the NSC slightly increased by 1–5% due to the addition BMF, whereas that of the HSC with BMF was, on average, 6% lower than that of their plain counterparts. The NSC with BMF exhibited significant improvements of 10–52% in the splitting tensile strength, 18–56% in the flexural strength, and 17–27% in the abrasion resistance. The enhancement caused by the addition of BMF was less pronounced for the HSC, where maximum respective improvements of 22, 25, and 4% were recorded. The NSC and HSC with BMF exhibited a similar reduction in the water absorption (max. of 12%), chloride penetrability (max. of 19%), and a comparable improvement in the bulk resistivity (max. of 21%), relative to those of their plain counterparts. The flexural test results along with an inverse analysis were employed to develop new tensile softening laws of concrete with different BMF volume fractions.

This study aims to examine the impact of using basalt macro-fibers (BMF) on characteristics of concrete made with recycled concrete aggregates (RCA). Test variables included the initial concrete grade (normal- and high-strength concrete (NSC and HSC)), RCA replacement percentage (30 and 60%), and BMF volume fraction (ν_f = 0.5 to 1.5%). The compressive strength reduction in the plain concrete caused by RCA was sensitive to the RCA replacement percentage rather than the initial concrete grade. The splitting and flexural strength reductions of the plain HSC caused by RCA were more significant than those of their NSC counterparts. The use of BMF compromised the concrete workability. Such a detrimental effect increased with the BMF content and was more pronounced for the HSC with 60% RCA. Reinforcing of RCA-based concrete with BMF tended to improve the mechanical properties. In some instances, the use of BMF at ν_f > 1% caused a decay in the strength gain. The addition of BMF to RCA-based concrete had a potential to fully restore the original splitting and flexural strengths of plain concrete mixtures made with natural aggregates (NA). The increase in the compressive strength of the RCA-based concrete caused by BMF was, however, not sufficient to fully restore the original strength of the NA-based plain concrete. The resistances to water penetration and abrasion of the RCA-based concrete improved by up to 17% and 47%, respectively, due to the addition of BMF. Idealized tensile softening laws were established for RCA-based concrete reinforced with BMF.