## 1 Introduction
Three of these methods were previously compared [42] when determining the absorption capacity of various FRAs and natural aggregates. Such results showed that the electrical conductivity method had less dispersion and greater repeatability than the other alternatives. On this basis, the electrical conductivity method was chosen in the present work for further analysis. This method was also used by [PERSON] et al. [38], who reached similar conclusions about its viability. The electrical conductivity method determines the saturated surface dry (SSD) state by examining the relationship between electrical conductivity and surface moisture on fine aggregate particles. When aggregate particles have water on their surfaces, liquid bridges form and carry electricity. When water is lost, these bridges disappear, and contact is only possible through solid-solid contact points [43]. Because the current is not well transported through the solid contact between the particles, as the surface water evaporates, conductivity decreases up to a threshold point wherein liquid bridges are no longer present. The conductivity measurement methodology uses a four-point configuration. This method of measuring electrical conductivity is standardized for soil moisture [44], and it has been used in several studies to evaluate concrete saturation levels and their relationships with reinforcement corrosion [45; 46]. The electrical conductivity method has proven effective in determining the SSD state of natural sand and the FRA derived from concrete crushing. However, the potential effect of the particle size range of the material on the test result remains unknown [47]. In this regard, [PERSON] et al. [48] measured the water absorption (WA) of differently sized fractions of several FRAs (Figure 1). They concluded that when the paper sheet method is compared to the cone method the finest fraction demonstrates a greater difference than the coarser fraction. Moreover, the authors concluded that the cone method underestimates the WA of the finest fractions, whereas the paper sheet method [37] overestimates it. The case for the electrical conductivity method may be similar to the paper method. Both depend on contact points per mass unit (paper-particle or particle-particle depending on the case). The potential effects of the particle size must be addressed to define the reliability of these methods. In order to eliminate the impact of incorrect WA determination on the effective w/c ratio in concretes in which FRAs are used, this study expands upon previous studies on the electrical conductivity method by investigating the potential influence of particle size. Only through an efficient determination of the WA of FRCA can the actual influence of FRA on concrete performance be determined. Previous studies [42] validated the method based on its reproducibility and repeatability. However, the present additional studies on the potential influence of particle size and composition further supports the universal applicability of the method to manufacture FRAs of different sizes. To that end, two types of FRA and one manufactured FNA with a homogeneous composition were tested, both of which was sieved into differently sized fractions to determine the absorption capacity of each fraction separately and compare these to that of the aggregate as a whole. The relationship between aggregate features and WA was also studied.