## 5 Results  
Figure 2 shows the cumulative MIP curves with pressures converted into pore entry sizes. The assumption of different contact angles results in very similar curves for all hemicycles except for the first intrusion. Some hysteresis for the first cycle maintains even with the consideration of the different contact angles. A supplementary explanation is thus  
needed for this first intrusion. For the second and third cycles, the change in the contact angle seems sufficient to fully explain the hysteresis. As the retraction curve is parallel to the second and third cycles, the second contributor to the hysteresis during the first cycle is most likely the filling of ink-bottle pores. The intrusion for the second and third cycles are almost identical for all the series. Only two MIP cycles are required to collect all the information. The third cycle is useful for confirming the data from the second cycle, but it does not provide new information. The pore volume of each sample correlates to the corresponding w/b ratio. For mixes only containing Portland cement, the w/b ratio is the only parameter determining the porosity of the samples with a same curing treatment. The inclusion of GGBFS in G40 and GL40 series contributes to a reduction of the pore volume in comparison with P40, which has the same w/b ratio. In fact, results of G40 and GL40 are comparable to P35, meaning that in practical terms, the use of GGBFS is equivalent to a reduction from w/b = 0.40 to a w/b = 0.35. Moreover, the differences between the first intrusion and the second intrusion are smaller for samples containing GGBFS than for samples without GGBFS. This difference is interpreted as the irreversible process of filling ink-bottle pores. The absolute value for the irreversibly intruded volume is lower for G40 and GL40. The highest irreversibly intruded volume relative to the total intruded volume is between 66% (P35), and the lowest is 39% (P45). Values for all mixes were within this range, with values near 60% as the most frequent. No consistent relationship between the relative irreversibly intrudable volume of  
Figure 2: Cumulative curves for the multicycle MIP for mixes (**a**) P35, (**b**) P40, (**c**) P45, (**d**) G40, (**e**) GL40 and (**f**) L40. the samples and their composition was detected. It would be reasonable to consider this volume as an indirect assessment for pore connectivity, but more research in this regard is necessary for conclusive results. The effect of LP was relative to the overall composition of the mix. For GL40, the low LP content and its synergy with GGBFS did not result in significant differences compared to G40. For L40, the individual effect of the LP can be mostly regarded as dilution of cement phases. In this case, the MIP showed higher porosity for L40 than for P40 and even P45. This effect could have been different if LP is incorporated by intergrinding with clinker during cement manufacture, as in that case, the particle packing of the system improves thanks to the lower hardness of limestone in comparison with clinker [25]. Figure 3 shows the derivative MIP curves with the pore entry size distributions for all samples. The pore entry size distribution from the first intrusion shows a similar shape as for the second and third cycles. After the first cycle, no noticeable modification of the pore entry size distribution is noted with the applied procedure up to a maximum pressure of 200 MPa. The critical pore entry size and threshold pore entry size are indicated for each sample. No significant differences for this parameter are observed for the three cycles. The pore entry size distribution correlates with the expected pore structure for each sample. For the most porous samples, P45 and L40, a second peak for pore entry size emerges in the micropore size range. For the rest of the mixes, this peak is beyond the measured range of pore entry sizes, as a maximum pressure of 200 MPa was applied in all cases.