Cement Analysis by the Pressed Powder Method According to ASTM C114-11

Application Note XRF1045


Cement is one of the most important materials for construction. Many kinds of hydraulic cements, including Portland cement, with various physical properties, are produced by changing the composition of clinker minerals; therefore, it is important to control the chemical composition of cement products and interim products.
ASTM C114-11 covers chemical analysis of hydraulic cement. In this standard, procedures of wet chemical analysis are mainly described and X-ray fluorescence (XRF) spectrometry is mentioned as an example of “Rapid Test Methods.” In practice, XRF spectrometry has been used for chemical composition analysis of cement owing to its simple sample preparation and high precision.

This application note demonstrates quantitative analysis for Portland cement by the pressed powder method according to ASTM C114-11 on Rigaku Supermini200, a benchtop sequential wavelength dispersive XRF spectrometer.

ASTM C114-11 and calibration standards

The standard ASTM C114-11 has the following descriptions about “Rapid Test Method”:

•    Using the test method chosen, make single determinations for each analyte under consideration on at least seven CRM (Certified Reference Material) samples. Complete two rounds of tests on different days, repeating all steps of sample preparation. Calculate the differences between values and averages of the values from the two rounds of tests.

•    When seven CRMs are used in the qualification procedures, at least six of the seven differences between duplicates obtained of any single analytes shall not exceed the limits shown in Table 1 and the remaining differences by no more than twice that value.

•    For each analyte and each CRM, the average obtained shall be compared to the certified concentrations. When seven CRMs are used in the qualification procedure, at least six of the seven averages for each analytes shall not differ from the certified concentrations by more than the value shown in Table 1, and the remaining average by more than twice that value.

The maximum permissible variations in analysis results defined in ASTM C114-11 are listed in Table 1.

ASTM C114-11 directs that acceptable reference cements are NIST CRMs, or  other reference cements traceable to  
the NIST CRMs.

In this application note, seven NIST CRMs (SRM1881a, 1884a, 1885a, 1886a, 1887a, 1888a and 1889a) were used for calibration and a qualification test.


The Supermini200, a benchtop sequential wavelength dispersive X-ray fluorescence 
(WDXRF) spectrometer, is designed to minimize the peripherals in installation such as cooling water, power supply, installation area, etc. The Supermini200 has good sensitivity for light elements such as Na, Mg, P and Cl relative to EDXRF systems, and does not show any spectral overlap between typical analytes for cement raw meal, owing to high spectral resolution of the  WD optics.

The Supermini200 is equipped with an air-cooled 200 W X-ray tube and up to three analyzing crystals, in which elements from fluorine to uranium can be analyzed. The Supermini200 has the same base software as the ZSX Primus series and, therefore, the software is user-friendly and flexible.

Sample preparation

Sample preparation for X-ray fluorescence analysis is easier than other analytical methods in general. It is important to obtain fine grain size for samples when grinding in order to reduce the influence of grain size on analyzed results. In view of processing many samples continuously, the cleaning of grinding containers to avoid contamination from prior samples should be able to be performed in a simple manner. When grinding cement samples, the samples can stick to the inner wall of the container, which causes a problem in cleaning. In order to avoid the problem, n-hexane was added as a grinding agent to prevent the samples from sticking to the wall of the tungsten carbide container (the wet grinding method; see Figure 1).

A binder was mixed with the ground cement powder samples (the ratio of sample to binder was 10 to 1). Four grams of the mixture was pressed into an aluminum ring (inner diameter, 32 mm) at 150 kN.

XRF1114 Figure 1 Comparison of container

Figure 1: Comparison of the condition in the container after pulverizing.


Measurements were performed in vacuum on the Supermini200 with a 200 W Pd target X-ray tube for the components listed in Table 1. 

Table 1: Maximum permissible variation (unit: mass%)

Analyte Maximum difference between duplicates Maximum difference of the average of duplicates from the certificate values
SiO₂ 0.16 ±0.2
Al₂O₃ 0.20 ±0.2
Fe₂O₃ 0.10 ±0.10
CaO 0.20 ±0.3
MgO 0.16 ±0.2
SO₃ 0.10 ±0.1
Na₂O 0.03 ±0.05
K₂O 0.03 ±0.05
TiO₂ 0.02 ±0.03
P₂O₅ 0.03 ±0.03
ZnO 0.03 ±0.03
Mn₂O₃ 0.03 ±0.03
Cl 0.003 N/A


Measurement condition is shown in Table 2.

Table 2: Measurement condition

X-ray tube Pd target, 200 W end-window type
Tube condition 50 kV and 4.0 mA
Analysis area 30 mm in diameter
Path atmosphere Vacuum
Element Si Al Fe Ca Mg S Na
Primary filter Out Out Out Out Out Out Out
Counting time (s) 40 40 20 40 60 40 60
Element K Ti P Zn Mn Cl  
Primary filter Al Out Out Out Out Out  
Crystal PET LiF PET LiF LiF PET  
Detector PC SC PC SC SC PC  
Counting time (s) 40 20 40 60 60 60  

Note) LiF: LiF(200), PC: F-PC


The results obtained in the calibration curves are shown in Table 1 and Fig. 2. A matrix correction method is applied to the calibrations. The symbol ⚬ shows the data point before the correction and the symbol ◆ shows the data after correction in the calibration charts.

The accuracy of calibration is calculated by the following formula:

$Accuracy = \sqrt{ \frac{\sum_i{(C_i-\hat{C}_i)^2}}{n-2} }$

$C_i$: calculated value of standard sample
$\hat{C}_i$: reference value of standard sample
n : number of standard samples. 

XRF1045 Figure 2 Calibration curves of Portland cement.

Figure 2: Calibration curves of Portland cement.

Qualification test for ASTM C114-11

The results are listed in the Table 4, comparing with the values of ASTM C114 requirement.

The results prove that the analysis method demonstrated in this application note meets  the requirements described in ASTM C114-11. (below)

Qualification test for ASTM C114-11

Quantitative analyses have been carried out for the seven NIST SRMs of Portland cement using the calibration curves obtained above.

Table 3: Calibration results (unit: mass%)

Analyte Calibration range Accuracy
SiO₂ 18.637 - 22.38   0.15
Al₂O₃ 3.875 - 7.06   0.096
Fe₂O₃ 0.152 - 3.09   0.024
CaO 57.58 - 67.87   0.11
MgO 0.814 - 4.475   0.057
SO₃ 2.086 - 4.622   0.049
Na₂O 0.021 - 1.068   0.0055
K₂O 0.093 - 1.228   0.0027
TiO₂ 0.084 - 0.366   0.0022
P₂O₅ 0.022 - 0.306   0.0014
ZnO 0.001 - 0.107   0.0009
Mn₂O₃ 0.007 - 0.259   0.0029
Cl 0.0019 - 0.013   0.0007

Table 4: Qualification test results (unit: mass%)

  Analyte   Difference between duplicates Difference of the average of duplicate from the certificate values
Limit (ASTM) Maximum difference Limit (ASTM) Maximum difference
SiO₂ 0.16 0.08 0.2 0.2
Al₂O₃ 0.20 0.03 0.2 0.1
Fe₂O₃ 0.10 0.01 0.10 0.04
CaO 0.20 0.12 0.3 0.2
MgO 0.16 0.03 0.2 0.1
SO₃ 0.10 0.06 0.1 0.1
Na₂O 0.03 0.00₅ 0.05 0.01
K₂O 0.03 0.01 0.05 0.01
TiO₂ 0.02 0.00₃ 0.03 0.00₄
P₂O₅ 0.03 0.00₃  0.03 0.00₃
ZnO 0.03 0.00₁ 0.03 0.00₂
Mn₂O₃ 0.03 0.00₂ 0.03 0.00₂
Cl 0.003 0.00₁ N/A 0.00₁

Table 5: Repeatability test results

  Analyte   Certified value (SRM1889a) Results of 10-time consecutive measurements
1st pressed pellet 2nd pressed pellet
Average Standard deviation Average Standard deviation
SiO₂ 20.66 20.714 0.032 20.700 0.017
Al₂O₃ 3.89 3.857 0.007 3.851 0.010
Fe₂O₃ 1.937 1.915 0.005 1.917 0.008
CaO 65.34 65.349 0.031 65.388 0.026
MgO 0.814 0.882 0.005 0.879 0.004
SO₃ 2.69 2.671 0.004 2.695 0.005
Na₂O 0.195 0.194 0.006 0.193 0.005
K₂O 0.605 0.607 0.004 0.606 0.004
TiO₂ 0.227 0.227 0.005 0.226 0.007
P₂O₅ 0.11 0.111 0.001 0.112 0.001
ZnO 0.0048 0.0050 0.0000 0.0047 0.0005
Mn₂O₃ 0.2588 0.2590 0.0018 0.2607 0.0018
Cl 0.0019 0.0018 0.0004 0.0015 0.0005

Repeatability test

To demonstrate the stability of the instrument, the duplicated pressed pellets of NIST SRM 1889a were measured 10 times consecutively. The test results are listed in Table 5. The results show the good measuring precisions.

In comparison with the values of the limits defined in ASTM C114-11 shown in Table 4, the standard deviations of the repeatability test obtained meet or exceed the ASTM C114 limits. The results demonstrate that the performance of the Supermini200 meets or exceeds the precision requirements for hydraulic cement analysis as stated in ASTM C114-11.


The qualification test for ASTM C114-11 demonstrated that the test results on the Supermini200 using pressed powder briquettes of wet-ground samples meet the requirements  for analysis of hydraulic cement defined in ASTM C114-11.

The precision obtained by the repeatability test  is much better than the defined values required in ASTM C114-11.

The Supermini200 is a wavelength-dispersive benchtop X-ray fluorescence spectrometer equipped with a newly developed high-power  air-cooled X-ray tube that does not require  cooling water. The spectrometer configuration results in high sensitivity, relative to benchtop energy-dispersive XRF spectrometers, for light elements such as Na or Mg, as well as heavy elements.


ASTM C114-11 Standard Test Methods for Chemical Analysis of Hydraulic Cement.


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