## 1 Introduction
The original equivalent mortar volume (EMV) method proposed by [PERSON] [4] and [PERSON] [5] is considered effective for structural concrete mixes, typically with about 800 kg/m\({}^{3}\) of fine aggregate. However, the characteristics of the EMV method lead to lower fine aggregate amounts, resulting in a rough mix and slump loss [5; 13], but these are acceptable for paving concrete. The low slump problem may be overcome in paving concrete by forcibly vibrating the pavement surface with a slipform paver to finish it [13]. In response to these issues, [PERSON] et al. [27] proposed a revised EMV method. It was assumed that some part of the RM volume fraction may be arithmetically considered as that of the original virgin aggregate (OVA), whereas the other part is considered as total mortar (TM). Figure 1 shows the concepts of different mix designs such as the modified EMV as well as traditional mixture designs. Note that TCA denotes the total coarse aggregate volume. Looking at the conventional mix design in Figure 1b, it can be seen that the TM volume of RCA concrete is greater than the TM volume of natural aggregate (NA) concrete, shown in Figure 1a. It is shown in Figure 1b that RCA is the sum of RM and OVA (equal to TCA). Therefore, the traditional RCA concrete mix design yields TM volume increase, which successively influences material properties. Figure 1c illustrates the unique characteristics of the EMV method. As explained before, the TM volume in the RCA concrete shown in Figure 1c, which is considered as the sum of the new mortar (NM) and RM volumes, is equal to the TM volume of NA in the traditional concrete shown in Figure 1a [8]. The NM volume in Figure 1c decreased in proportion to the RM amount. In the modified EMV model shown in Figure 1d, RM adhering to RCA acts as aggregate in the fresh state concrete, and later hardens as mortar. Now, the volume of RM of RCA concrete is treated by the mortar volume fraction (RMa) and the other aggregate volume fraction (RMb). Additional explanation of the revised EMV concept can be found in the reference [13]. Previous studies have mainly focused on obtaining test results for the elastic modulus [5; 8; 12; 13; 27; 28] and drying shrinkage [28; 29; 30] of RCA concrete mixes with EMV mixes, similar to those of mixes made with NCA or RCA by the traditional mix proportioning method. It should be noted that previous studies on mixes made using the revised EMV method did not consider improvement in compressive strength. Test results illustrated that RCA concretes made with the revised EMV mix method did not always yield compressive strengths that were similar to those of the control mixes [5; 8; 12; 13; 27; 28]. Despite test results comparable to those for the modified EMV mix designs, the model is still subject to the slump loss problem. It should be noted that previous test results were obtained from EMV mixes, which showed lower slump values with variation of air content, in comparison to the control NA concrete mix proportioned from the ACI mix design. Therefore, this study sought to assess the influence of the revised EMV mix proportion method on the mechanical strength and drying shrinkage properties of RCA concretes, where the same W/C ratio, and slump and air content were applied. This experimental study used three grades of RCAs with different water absorption ratios, where two different RCAs (with water absorption ratio of 3.82% and 6.61%) were crushed from the same source of old concrete. The third RCA was produced from old PC concrete sleepers.