## 1 Introduction  
The construction industry has been identified as one of the most significant worldwide polluters [1]. To lessen its environmental impact, different strategies have been proposed and used in various countries. Waste minimization and recovery are unavoidable practices in the pursuit of sustainability. Every year, 41 billion tons of aggregates are consumed by the construction industry [2]. To reduce the environmental impact of concrete, several waste materials have been studied for raw material replacement in concrete production [3; 4; 5]. In this regard, the extraction of natural aggregates far exceeds sustainable levels [3; 6; 7]. The indiscriminate extraction of river sand causes a chain reaction that exacerbates the effects of tsunamis, interferes with fishing and crops, and increases the levels of salinization in the water [3; 8]. Furthermore, numerous studies show that an increase in sand consumption implies illegal trade, which leads to violence, social conflict, and the deterioration of habitats [7; 9]. The use of FRA may contribute to changing this reality. In formal markets, because of the need to limit the exploitation of non-renewable natural resources, the use of recycled aggregates (RA) obtained from crushing waste concrete as an aggregate to manufacture new concrete is becoming more common in the ready-mixed concrete industry. This practice has the potential to reduce the industry's carbon footprint by up to 23% [10], as well as reduce the volume of waste in landfills. Different countries' regulations allow for different percentages of RA to be used in structural and non-structural concrete [11; 12; 13; 14]. The use of the coarse fraction is permitted by most of them, but not the use of the fine fraction. This distinction between the two fractions of RA is most likely due to a lack of agreement on the effects of fine recycled aggregate (FRA), as opposed to the consensus on the technical feasibility of using coarse recycled aggregate (CRA) without affecting concrete performance significantly [15; 16; 17; 18]. Conflicting presumptions remain regarding the viability of FRA as an aggregate for concrete production. Some authors report that concretes containing FRA achieve strength levels comparable to or even higher than those of the reference concrete [19; 20], whereas other researchers report strength decreases of more than 30% when FRA is used as a partial replacement for natural fine aggregate (FNA) [21; 22; 23; 24]. Similarly, there are significant discrepancies regarding the influence of FRAs on concrete consistency. While some works report similar consistency values between reference mixes and those made with FRA [25; 26], other studies report up to a 60% reduction in slump even when the FRA is brought to its saturated surface dry state (SSD) before use [26; 27]. The main properties of recycled aggregates (density, porosity, and strength) differ from those of natural aggregates due to the presence of hardened cement paste [26; 27; 28; 29; 30]. Compared to natural aggregates, this paste reduces density and resistance and increases the absorption of FRA. According to recent studies [31; 32], the effective w/c ratio of recycled concrete is not an efficient parameter to correlate with the compressive strength of the concrete in which the RA is used. [PERSON] et al. [32] conclude that the total w/c ratio (which includes the water used to compensate for the greater absorption of the aggregate) has a very good correlation with compressive strength. These findings could explain the contradictory results regarding the influence of FRAs on concrete performance. A reliable determination of the absorption of the aggregates, as well as its water uptake within fresh concrete, is a critical step to avoid changes in the w/c and, consequently, in concrete performance. At least eight methods are available in the literature to determine aggregate absorption capacities [33; 34; 35; 36; 37; 38; 39; 40; 41].