## 4 Materials and Methods  
Table 1 presents the compositions and designations of the studied concrete mixes. Two concrete mixes with w/b = 0.40 and containing GGBFS and LP as partial replacement of Portland cement were prepared: G40 with 35 wt.% GGBFS, GL40 with 25 wt.% GGBFS + 10 wt.% LP, and L40 with 25 wt.% LP. Further, control mixes with 100% Portland cement (PC) were prepared as a reference with w/c = 0.35 (P35), 0.40 (P40), and 0.45 (P45). Thus, in the designation of the concrete mixes, G and L indicate the incorporation of GGBFS and LP, respectively, whereas P indicates Portland cement as the only cementitious component. Figure 1: Correlation between pressure and the adapted surface of mercury against the rough pore wall. The figures in the designation of mixes indicate the water-to-binder ratio multiplied by 100. The properties of PC, GGBFS and LP are presented in Table 2. The strength activity index of GGBFS was 0.95. Additional specimens were cast for the determination of compressive strength (3 cylinders of 100 mm in diameter and 200 mm in height per age and mix) and porosity by vacuum water absorption (3 cylinders of 100 mm in diameter and 100 mm in height per mix). The entrained air was measured in the fresh state by means of the pressure method. For MIP measurements, prismatic concrete specimens (75 \(\times\) 100 \(\times\) 250 mm\({}^{3}\)) were cast and cured for 28 days in a wet room, RH \(>\) 95%, temperature (23 \(\pm\) 2) \({}^{\circ}\)C. These specimens were aged in the laboratory, average RH \(\sim\) 75% and temperature (15-30) \({}^{\circ}\)C for 2 years. Uncarbonated samples of about 4 g of crushed pieces of material were taken from the core of the specimens and used for the MIP experiments. Applying MIP to concrete samples has some advantages and disadvantages in comparison with determination on cement paste. Concrete samples include an interfacial transition zone around the aggregates with a differentiated pore structure from the one \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Materials (kg/m\({}^{3}\))** & **P35** & **P40** & **P45** & **G40** & **L40** & **GL40** \\ \hline Water & 133 & 140 & 144 & 140 & 140 & 140 \\ PC & 380 & 350 & 320 & 227 & 262 & 227 \\ GGBFS & - & - & - & 123 & - & 88 \\ LP & - & - & - & - & 88 & 35 \\ Siliceous sand & 938 & 944 & 959 & 945 & 945 & 945 \\ Crushed granite 6–20 mm & 980 & 980 & 980 & 980 & 980 & 980 \\ Superplasticizer (l) & 6.2 & 5.9 & 6.0 & 4.9 & 4.2 & 4.1 \\ Entrained air in fresh & 3.0 & 3.1 & 3.0 & 3.2 & 3.5 & 3.4 \\ state (\%) & & & & & & \\ \hline Properties & & & & & & \\ \hline Slump (mm) & 80 & 100 & 60 & 100 & 90 & 70 \\ Unit weight in fresh state & 2404 & 2417 & 2392 & 2390 & 2385 & 2354 \\ (kg/m\({}^{3}\)) & & & & & & \\ Accessible porosity by & & & & & & \\ water absorption & 8.02 & 8.68 & 8.90 & 9.10 & 8.78 & 9.49 \\
28 d (\%) & 7 d & 54.2 & 47.6 & 37.8 & 47.6 & 37.4 & 43.6 \\ Compressive & 28 d & 60.2 & 47.6 & 44.3 & 52.6 & 42.2 & 51.1 \\ strength (MPa) & 90 d & 63.2 & 52.8 & 45.9 & 58.1 & 47.3 & 60.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Mix proportions and properties of concretes. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**ID** & **PC** & **GGBFS** & **LP** \\ \hline Blaine specific surface area (m\({}^{2}\)/kg) & 380 & 373 & 476 \\ Mass retained on sieve 75 \(\mu\)m (\%) & 1.3 & \(<\)0.01 & 1.6 \\ Density & & 3.11 & 2.87 & 2.75 \\ \hline Loss on ignition & 2.14 & 0.87 & 36.01 \\ Insoluble residue & 2.50 & 3.40 & 6.65 \\ SO\({}_{3}\) & 2.41 & 3.58 & 0.21 \\ MgO & 2.76 & 9.36 & 0.76 \\ Chemical & SiO\({}_{2}\) & 19.93 & 30.49 & 11.58 \\ composition (\%) & Fe\({}_{2}\)O\({}_{3}\) & 4.00 & 0.29 & 0.68 \\ Al\({}_{2}\)O\({}_{3}\) & 4.30 & 10.68 & 1.82 \\ CaO & 60.38 & 38.17 & 45.82 \\ Na\({}_{2}\)O & 0.14 & 1.42 & 0.92 \\ K\({}_{2}\)O & 0.85 & 0.44 & 0.19 \\ Cl\({}^{\dagger}\) & 0.012 & \(<\)0.001 & 0.010 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Properties of Portland cement and supplementary cementitious materials. of the matrices.