Characterization data of reference cement CEM I 42.5 R used for priority program DFG SPP 2005 “Opus Fluidum Futurum – Rheology of reactive, multiscale, multiphase construction materials”

A thorough characterization of starting materials is the precondition for further research, especially for cement, which contains various phases and presents quite a complex material for fundamental scientific investigation. In the paper at hand, the characterization data of the reference cement CEM I 42.5 R used within the priority program 2005 of the German Research Foundation (DFG SPP 2005) are presented from the aspects of chemical and mineralogical compositions as well as physical and chemical properties. The data were collected based on tests conducted by nine research groups involved in this cooperative program. For all data received, the mean values and the corresponding errors were calculated. The results shall be used for the ongoing research within the priority program.


a b s t r a c t
A thorough characterization of starting materials is the precondition for further research, especially for cement, which contains various phases and presents quite a complex material for fundamental scientific investigation. In the paper at hand, the characterization data of the reference cement CEM I 42.5 R used within the priority program 2005 of the German Research Foundation (DFG SPP 2005) are presented from the aspects of chemical and mineralogical compositions as well as physical and chemical properties. The data were collected based on tests conducted by nine research groups involved in this cooperative program. For all data received, the mean values and the corresponding errors were calculated. The results shall be used for the ongoing research within the priority program.
© 2019 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/). Table 1 lists the universities, research institute, and cement company involved in the characterization of the CEM I 42.5 R and the abbreviations are explained respectively. Fig. 1 shows selected SEM pictures of cement grains with different magnifications.

Characterization data of oxide composition and phase contents
In Fig. 2 (3) were measured by one research group from one single batch but different bags. In Fig. 2(b) SO 3 * means the value obtained by the X-ray fluorescence analysis (XRF) and SO 3 ** indicates the value captured by the wet chemistry method. The same meanings of * and ** are also suitable for the other data shown in Fig. 2. Unless otherwise stated, the oxide composition shown in Specifications Table   Subject Ceramics and Composites Specific subject area Building materials; Cement Type of data Value of the Data The data are useful because a well characterization on CEM I 42.5 R from aspects of composition and properties are shown in this paper. Besides, the corresponding variation trend on cementitious materials is also included. All the research groups involved in the DFG SPP 2005 priority program and other related researchers can use these data for their further study. The data provide a solid foundation for the further research involved in the DFG SPP 2005 priority program. Besides, all researchers can refer to this variation trend on cementitious materials in their own study. Seven universities, one research institute and one company are involved to conduct common characterization tests on the same samples. Fig. 2 is measured based on XRF analysis. Furthermore, due to the quite low content of Cl À of 0.02 wt.% only, the amount of Cl À is not included in Fig. 2.
In the legend of the figures of this paper, IQR means the interquartile range, namely the range between 25 th and 75 th percentiles (as shown in the area in the grey box). The specific explanation could be found on the website [2]. The error bar shows the range within 1.5 times of IQR. The median line indicates the 50 th percentile and the mean value is calculate based on data from all the samples within the 1.5 IQR range and does not include outliers.

Characterization data of physical properties
The true density of the CEM I 42.5 R was measured by Helium pycnometer method according to standard EN 1097-7: 2008 [4]. Results are shown in Fig. 4. The same experiment was conducted by different groups, as shown by the hexagon, and then the mean value was calculated.
The specific surface area of the CEM I 42.5 R was measured by the Blaine method according to EN 196-6: 2018 [5] and the results are shown in Fig. 5.
The specific surface area of the CEM I 42.5 R was measured by the BET method according to ISO 9277: 2010 [6]. Results are shown in Fig. 6. The numbers in brackets indicate the values from the same sample but different pre-treatment methods that were conducted by the same group.
Laser diffraction was applied to measure the particle size distribution (PSD) of the cement by eight different groups according to the method described in ISO 13320: 2009 [7]. The average distribution line was calculated, as shown in Fig. 7. The shadow areas below and above this average line indicate the scope of the testing results. The characterized particle size distributions of the cement (d (0.1), d (0.5) and d (0.9)) are shown in Fig. 8.

Characterization data of other properties
Water demand, as well as initial and final setting time were measured according to the standard EN 196-3: 2016 [8]. Flexural and compressive strength were measured according to the standard EN 196-1: 2016 [9]. The results are shown in Figs. 9e11.
The cement hydration with a water to cement ratio of 0.434 at the temperature of 20 C was characterized independently by three different groups according to the method described in EN 196-    11: 2018 [10]. The results are shown in Fig. 12. The shadow areas below and above the average line indicate the scope of the test results.

Experimental design, materials, and methods
All samples analyzed in this campaign stemmed from the same batch of cement production. The sample amount delivered to the different research groups were between a few kilograms up to several tons. The material was stored in closed containers, and the various groups took a representative sample from their own sub-batch.
For the characterizations of the CEM I 42.5 R, EN 196-2: 2013 was applied for the assessment of the oxide composition, insoluble residue and loss on ignition. Density was measured according to EN 1097-7: 2008; specific surface area by the Blaine method was measured according to   SEM images were recorded on uncoated cement powder with a Nova NanoSEM 230 (FEI, Netherlands) equipped with a field-emission gun (Schottky emitter). For lower magnification, a lowvacuum-detector (LVD) applying 12 kV acceleration voltage and 0.9 mbar was used. For higher magnification, a through the lens detector (TLD) at 2 kV and 22 pA electric current was used under high vacuum conditions.
For the characterization of phase contents, powder-XRD combined with quantification of the patterns was used. In different research groups, different XRD devices with different analysis software were used. In one research group, XRD was performed in a Siemens D5000 with operation parameters given elsewhere [11]. Rietveld refinement was performed with the software Profex (3.12.1). In the software package, the fundamental parameters approach for Rietveld refinement was applied [12]. In another research group, the software package of Bruker Topas V5.0 was used for Rietveld refinement. In the software package, the fundamental parameters approach for Rietveld refinement was  implemented [13]. Additionally, an external standard [14] was applied in order to estimate the amorphous content of the CEM I 42.5 R, which was found to be negligible.

Acknowledgments
The authors gratefully thank the German Research Association (DFG) for funding the Priority Program DFG SPP 2005 project program "Opus Fluidum Futurum e Rheology of reactive, multiscale, multiphase construction materials" (project number 313773090) and HeidelbergCement AG for their supply of the cement.

Conflict of Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper Appendix. Average values and the standard deviation calculated based on the results from different groups