Proper execution of the CEMHYD3D v3.0 disrealnew.c computer program requires the prior creation of two supporting datafiles that provide the characteristics of the alkalis in the cement and the slag (if any) blended with the cement. Examples of these datafiles, which must have the filenames of alkalichar.dat and slagchar.dat, respectively, are as follows. Note also that these files must be located in the same physical directory as the executable disrealnew program.
Example Annotated alkalichar.dat datafile
0.093 sodium oxide content of the portland cement being modeled 0.186 potassium oxide content of the portland cement being modeled 0.017 readily-soluble (1 h) sodium oxide content of the portland cement 0.078 readily-soluble (1 h) potassium oxide content of the portland cement
All oxide contents are provided on a mass percentage basis.
Example Annotated slagchar.dat datafile (corresponds to the slag in second row of Table 2)
2714.219 molar mass of initial slag (g/mol) 4036.2 molar mass of slag hydration product (g/mol) 2.87 specific gravity of initial slag 2.35 specific gravity of slag hydration product 945.72 molar volume of initial slag (cm3/mol) 1717.53 molar volume of slag hydration product (cm3/mol 1.4333 Ca/Si molar ratio in initial slag 1.35 Ca/Si molar ratio in slag hydration product 15.0 Si atoms per molar unit of slag 5.533 H2O/Si molar ratio in slag hydration product 1.0 moles of "C3A" per mole of slag 1.0 slag reactivity factor (default value of 1.0)
The following inputs are required for execution of version 3.0 of the CEMHYD3D hydration model (main program disrealnew.c provided in Appendix B):
a negative integer random number seed,
the filename of the file containing the initial 3-D microstructure to be used in the hydration model,
for this file, the integer values assigned to C3S, C2S, C3A, C4AF, gypsum, hemihydrate, anhydrite, aggregate, and CaCO3 (separated by spaces). Typical values following phase distribution using the distrib3d.c program would be 1, 2, 3, 4, 5, 6, 7, 28, and 26.
the phase ID assigned to C3A in any fly ash particles present in the starting microstructure [31]. Often, there is no fly ash present in the microstructure (or no C3A present in the fly ash) and this value can be set to its default value of 35.
the filename of the file containing the initial 3-D particle ID microstructure to be used in the hydration model (for assessing setting behavior). Typically, this file is created during the execution of the genpartnew.c program.
the number of one-voxel (1 μm) particles of a phase to add. The program contains an iterative loop to continue to accept non-zero values for this parameter, so that the user can place different phase one-voxel particles, at their discretion. This iterative process is terminated by the user inputting a value of 0 for the number of one-voxel particles to add. Every time a non-zero entry is input, the next entry must be the phase ID of the particles to be placed. The phase IDs corresponding to each phase can be found in a series of #define statements near the top of the disrealnew.c listing in Appendix B.
the number of cycles of the hydration model to execute. Note that this value can be set to zero if, for example, the user wants to output the initial microstructure before any hydration, but after addition of all of the one- voxel particles.
a flag indicating if hydration is to be initially under (0) saturated or (1) sealed conditions,
the maximum number of diffusion steps to take in a given dissolution cycle (typically a value of 500 is used here),
a prefactor and a scale factor for the nucleation probability of CH according to an exponential function [32],
a prefactor and a scale factor for the nucleation probability of calcium sulfate dihydrate (gypsum) forming from the hemihydrate and anhydrite forms of calcium sulfate,
a prefactor and a scale factor for the nucleation probability of C3AH6,
a prefactor and a scale factor for the nucleation probability of FH3,
the frequency (in cycles) for examining the percolation properties of the capillary pore space (this examination can be totally avoided by setting this parameter to a value larger than the requested number of hydration cycles). If active, for hydrations that are initiated under saturated conditions, the CEMHYD3D model will automatically switch to sealed curing (with its accompanying self-desiccation, etc.), when the capillary porosity becomes depercolated in all three principal directions through the 3-D microstructure.
the frequency (in cycles) for examining the percolation properties of the solids (set point) with a typical value being 5,
the frequency (in cycles) for outputting the hydration characteristics of all cement particles present in the microstructure,
the frequency (in cycles) for outputting the hydrating microstructure to a file with a filename that indicates the starting microstructure name, the number of cycles, hydration conditions, etc. as will be detailed in the Outputs subsection to follow,
the induction time in hours (time_induct) for use in converting model cycles to real time (now that the induction period is directly included in the hydration modeling, this value will normally be set to zero),
the initial temperature of the system in degrees Celsius,
the ambient temperature in degrees Celsius,
an overall heat transfer coefficient between the hydrating specimen and its environment in units of J/(g·C·s) for hydration under semi-adiabatic conditions,
the activation energy (kJ/mol) for the cement hydration reactions (if no further information is available, a value of 40 kJ/mol is suggested for Type I ordinary portland cements [23]),
the activation energy (kJ/mol) for pozzolanic reactions,
the activation energy (kJ/mol) for slag hydration reactions,
the calibration factor (β) for converting model cycles to real time in hours based on an equation of the form time=time_induct+β·cycles·cycles [32],
the mass fraction of aggregates (0.0 for cement paste hydration) in the concrete mixture proportions (not that present in the 3-D microstructure being used, but that present in the concrete mixture being simulated; this is used for the direct simulation of adiabatic heat signature curves [33]),
a flag indicating if hydration is to be under (0) isothermal, (1) adiabatic/semi-adiabatic, or (2) temperature-programmed conditions. In the latter case, the time-temperature curing history for the simulation is read in from the file called temphist.dat located in the same directory as the executable disrealnew file.
a flag indicating if conversion of conventional C-S-H to pozzolanic C-S-H is (0) prohibited or (1) allowed,
a flag indicating if precipitation of calcium hydroxide on aggregate surfaces is (0) prohibited or (1) allowed [34, 35],
the number of slices to include in a hydration movie (the central slice of the microstructure will be output every nth hydration cycle to obtain a "movie" of the hydration with the number of individual frames provided here by the user); a value of 0 will avoid the output of a hydration movie completely,
a real number dissolution bias factor for the dissolution of one-voxel (soluble) particles in the 3-D microstructure (default value of 1.0) [30],
the number of cycles of hydration to execute before totally resaturating the 3-D microstructure. This allows for the simulation of sealed/saturated curing conditions [25], and is only relevant when the user selects to initiate hydration under sealed conditions, or the hydration has previously switched over to sealed conditions due to depercolation of the capillary porosity as described above.
a flag indicating if C-S-H morphology (geometry) is to be (0) random or (1) plate-like, and
a flag indicating if the computed pH of the pore solution influences the hydration kinetics: (0) no or (1) yes.
An annotated example datafile for 1000 cycles of saturated hydration of CCRL cement 152 (w/c=0.40) could be as follows:
-2794 random number seed cem152w04flocf.img filename containing input 3-D phase ID microstructure 35 phase ID for C3A in fly ash particles pcem152w04floc.img filename containing input 3-D particle ID microstructure 44990 number of one-pixel particles to add 1 add one-pixel particles of phase C3S 5850 number of one-pixel particles to add 2 add one-pixel particles of phase C2S 8692 number of one-pixel particles to add 3 add one-pixel particles of phase C3A 2631 number of one-pixel particles to add 4 add one-pixel particles of phase C4AF 1100 number of one-pixel particles to add 5 add one-pixel particles of gypsum 2062 number of one-pixel particles to add 6 add one-pixel particles of hemihydrate 839 number of one-pixel particles to add 7 add one-pixel particles of anhydrite 0 number of one-pixel particles to add 1000 number of cycles of hydration model to execute 0 flag for executing model under saturated conditions 500 maximum number of diffusion steps per cycle 0.0001 9000. nucleation parameters for CH 0.01 9000. nucleation parameters for gypsum (dihydrate) 0.00002 10000. nucleation parameters for C3AH6 0.002 2500. nucleation parameters for FH3 50 cycle frequency for checking pore space percolation 5 cycle frequency for checking total solids percolation 5000 cycle frequency for outputting particle hydration stats 5000 cycle frequency for outputting hydrated microstructures 0.00 induction time in hours 20.0 initial specimen temperature in degrees Celsius 20.0 ambient temperature in degrees Celsius 0.0 overall heat transfer coefficient 40.0 activation energy for cement hydration 83.14 activation energy for pozzolanic reactions 80.0 activation energy for slag hydration 0.00035 conversion factor to go from cycles to real time 0.72 aggregate volume fraction in actual concrete mixture 0 flag indicating that hydration is under isothermal conditions 0 flag indicating that C-S-H conversion is prohibited 1 flag indicating that CH/aggregate precipitation is allowed 0 number of slices to include in a hydration movie file 1.0 one-voxel dissolution bias factor 0 number of cycles to execute before resaturation 0 flag indicating that C-S-H morphology is random 1 flag indicating that pH does influence hydration kinetics