## Materials and Experimental Procedures
### Fresh and Hardened Concrete Tests  
Immediately after mixing was complete, a standard flow test to check the workability was conducted, as specified in ASTM C1437 [28]. The mini-flow cone was filled with fresh concrete. The initial concrete diameter was recorded as the average from four measurements; afterwards, the mini-cone was slowly removed to allow the concrete to flow. The flow table was then dropped 25 times within 15 s. The final diameter of the concrete was recorded as the average of four readings. Equation (2) was used to calculate the relative flow area for each mixture:  
\[\Gamma_{\mathrm{m}}=\frac{(d_{1}\times d_{2})-d_{0}^{2}}{d_{0}^{2}} \tag{2}\]  
where, \(\Gamma_{\mathrm{m}}\) = relative flow area; \(d_{1}\) and \(d_{2}\) = measured flow diameter after dropping; \(d_{0}\) = flow cone diameter (100 mm), and \(d_{0\mathrm{-avg}}\) = average value of \(d_{0}^{1}\) and \(d_{0}^{2}\) (measured flow diameter before dropping).  
The setting time of RPC was determined for six key mixtures according to ASTM C403 [29]. The initial and final set times were calculated from the plot of penetration resistance versus time elapsed from the initial contact of water and binder using simple linear regression from Equation (3):  
\[Log(PR)=a+bLog(t) \tag{3}\]  
where, \(PR\) = penetration resistance; \(t\) = the time elapsed from the initial contact of the water and binder; and \(a\) and \(b\) = regression constants. The initial set time corresponds to 3.45 MPa, and the final setting time corresponds to 27.6 MPa.  
As shown in Figure 1, a compressive strength test and flexural strength test called the modulus of rupture (MOR) were performed according to guidelines of ASTM C 109 [27] and ASTM C 293 [30], irrespectively. The average of three specimens at the testing age was used for analysis. The MOR was calculated using Equation (4):  
\[MoR=\frac{3 PL}{2 bd^{2}} \tag{4}\]  
where \(P\) = maximum applied load; \(L\) = span length; \(b\) = average width of the specimen; and \(d\) = average depth of the specimen.  
The drying shrinkage (time-dependent volume change) test of RPC was performed in accordance with ASTM C 157 and ASTM C490 [31; 32]. A digital length comparator with an accuracy of \(\pm\)0.0001 mm was also used to measure the linear dimension variation of specimens along the longitudinal  
Figure 1: Strength test setup: (**a**) compressive strength test; (**b**) flexural strength test.  
axis. The specimens were stored in an environmental chamber where the temperature was 23 \(\pm\) 2 \({}^{\circ}\)C, and relative humidity was 50 \(\pm\) 4% RH. The measurements for autogenous shrinkage (one-day cured specimen) were taken at the following intervals: every day up to an age of 7 days, every 3 days up to an age of 28 days, and every 14 days for up to an age of 56 days. The measurements for a seven-day cured specimen were taken at the following intervals: every 3 days for an age of up to 28 days, and every 14 days for an age of up to 56 days. Then, the drying shrinkage value was calculated using Equation (5):  
\[L=\frac{(L_{x}-L_{i})}{G}\times 100 \tag{5}\]  
where, \(L\) = change in the length at \(x\) age (%); \(L_{x}\) (mm) = (comparator reading of specimen at \(x\) age) \(-\) (comparator reading of reference bar at \(x\) age); \(L_{i}\) (mm) = (initial comparator reading of specimen) \(-\) (comparator reading of reference bar at the same time); and \(G\) = nominal gauge length (250 mm).