**3. Analysis of Results**

#### *3.1. Relevant Subject Areas and Yearly Publications*

The Scopus analyzer was employed to carry out this analysis to discover the most pertinent study fields. Engineering, materials science, and environmental science were found to be the leading three document-producing areas, with around 39, 27, and 10% of documents, respectively, accounting for a total 76% of contributions based on document count, as seen in Figure 3. Additionally, as seen in Figure 4, the kind of paper was evaluated in the searched term in the Scopus database. According to this research, journal articles, conference papers, journal reviews, and conference reviews accounted for almost 66, 25, 7, and 2% of total documents, respectively. The yearly trend in publications in the present research area from 1977 to 2021 is depicted in Figure 5, since the first document on the subject research field was discovered in 1977. In the research of RHA concrete, a slow

increase in the amount of publications was seen, with an average of roughly three papers per year up to 2000. Following this, there was a continuous increase in publications, with an average of roughly 20 papers each year from 2001 to 2016. The quantity of publications increased significantly during the previous five years (2017–2021), averaging approximately 110 each year.

**Figure 3.** The subject area of articles.

**Figure 4.** Various types of documents published in the related study field.

**Figure 5.** Annual publication trend of articles.

#### *3.2. Sources of Publications*

The assessment of publication sources was carried out using the VOSviewer on the collected bibliographic data. During the analysis, "bibliographic coupling" was selected as the "kind of analysis", while "sources" were retained as the "unit of analysis". At least ten papers per source restraint were set, and 14 of the 265 publication sources met these criteria. Table 1 shows the publishing sources that published a minimum of ten documents, providing data on RHA concrete, up to 2021, together with the amount of citations obtained during that time period. The main three sources/journals based on paper count are "Construction and building materials", "IOP conference series: materials science and engineering", and "Materials today: proceedings", with 110, 48, and 45 papers, respectively. Moreover, the top three sources based on the overall citations are "Construction and building materials" with 6797, "Cement and concrete composites" with 2268, and "Journal of cleaner production" with 1579. Remarkably, this exploration would provide a basis for upcoming scientometric investigations in the research of RHA concrete. In addition, prior traditional reviews were unable to generate scientific visualization maps.

Figure 6 illustrates a map of journals that have published a minimum of ten documents. The box size is proportional to the journal's impact on the current research area's document quantity; a bigger box dimension implies a superior impact. As an example, "Construction and building materials" has a bigger box than the others, implying that it is a source of considerable importance in that field. Five clusters were created, each of which is represented in the artwork by a different hue (red, blue, green, yellow, and purple). Clusters are formed on the basis of the research source's extent or the frequency with which they are co-cited in a similar article [102]. The VOSviewer created clusters of journals based on their co-citation patterns in published papers. For instance, the red cluster consists of six sources that have been co-cited several times in identical works. Additionally, nearly spaced frames (journals) in a cluster have stronger relationships than widely distributed frames. For instance, "Construction and building materials" is more strongly correlated with "Materials today: proceedings" than with "Journal of cleaner production".


**Table 1.** Publication sources with at least ten publications in the related research field up to 2021.

**Figure 6.** Scientific visualization of publication sources with at least ten publications in the related research area.
