EPA-600'R-94-053
April 1994
LABORATORY ASSESSMENT OF THE PERMEABILITY AND DIFFUSION
CHARACTERISTICS OF FLORIDA CONCRETES
PHASE I
METHODS DEVELOPMENT AND TESTING
Prepared by:
R. Snoddy
Acurex Environmental Corporation
4915 Prospectus Drive
P.O. Box 13109
Research Triangle Park, NC 27709
EPA Contract No. 68-DO-0141
Project Officer: David C. Sanchez
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
Prepared for:
U.S. Environmental Protection Agency
Office of Research and Development
Washington, DC 20460
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NOTICE
This document has been reviewed in accordance with
U.S. Environmental Protection Agency policy and
approved for publication. Mention of trade names'
or commercial products does not constitute endorse-
ment or recommendation for use.
ii
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ABSTRACT
The ability of concrete to permit air flow under pressure (permeability) and to permit the passage
of radon without any pressure difference (diffusivity) has not been well determined. To establish a
standard concrete mix and its maximum radon-resistant placement, these parameters needed to be
quantified and their relationship to concrete's physical properties evaluated. The concrete testing consisted
of separate permeability and diffusivity measurements and a set of preliminary measurements to determine
the size, weight, and porosity of each sample. Ten concrete samples were tested. Cylinders represented
one of the four general types of concretes manufactured in Florida. Permeability was measured with a
device developed for the project using custom software. The diffusion coefficient was determined with
a system developed by and purchased from Rogers and Associates Engineering Corporation. Two of the
samples had measured permeabilities 100 times greater than the other samples due to defects in the
concrete. All of the correlations of the various physical parameters were investigated, but there were
insufficient data to confidently determine any correlations. The most significant fault in this phase of the
research was the lack of unbiased, representative concrete slab samples.
i i l
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TABLE OF CONTENTS
Section Page
ABSTRACT i i i
LIST OF FIGURES vi
LIST OF TABLES vi
ABBREVIATIONS AND SYMBOLS vi i
EXECUTIVE SUMMARY viii
1.0 INTRODUCTION 1
2.0 EXPERIMENTAL PROCEDURES 3
3.0 DATA ANALYSIS 8
4.0 QUALITY ASSURANCE 11
5.0 RESULTS AND DISCUSSION 15
6.0 CONCLUSIONS .23
7.0 RECOMMENDATIONS 24
REFERENCES 25
BIBLIOGRAPHY 25
APPENDIX A: Permeability Data Analysis Derivation 26
APPENDIX B: Measurement Procedures 30
APPENDIX C: Permeability Software 36
APPENDIX D: Sample Permeability Data 43
APPENDIX E: Sample Diffusivity Data 45
APPENDIX F: Correlation Plots 46
v
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LIST OF FIGURES
Figure Page
1 Permeability Test System 6
2 Diffusion Test System 7
3 Example of Linearized Permeability Raw Data Graph 9
4 Permeability Coefficients 20
5 Bulk Diffusion Coefficients 21
6 Pore Space Diffusion Coefficients 22
LIST OF TABLES
Table Page
1 Diffusion Verification Tests 10
2 Comparison of Diffusion Standard Results 12
3 Data Quality 13
4 Sample ID and Source 15
5 Concrete Mix Design Data 16
6 Preliminary Measurement Data 17
7 Permeability and Diffusion Coefficients 17
vi
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ABBREVIATIONS AND SYMBOLS
°F
degrees Fahrenheit [°C=5/9(°F-32)]
ASTM
American Society for Testing and Materials
D
Diffusion coefficient (m2/s)
DCA
Department of Community Affairs
FC&PA
Florida Concrete and Products Association
gal
gallon (0.0038 m3)
in
inch (2.54 cm)
k
Permeability coefficient (m2)
lb
pound (0.45 kg)
oz
ounce (0.028 kg)
psi
pounds per square inch (6895 Pa)
RAECORP
Rogers and Associates Engineering Corporation
yd3
cubic yard (0.76 m3)
vii
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EXECUTIVE SUMMARY
Much of Florida's natural soil and the sand recovered from the phosphate mining/beneficiation
process there contain significant quantities of radium. Buildings constructed on these high-radium soils
have been found to contain elevated radon levels. Elevated inside radon gas levels can cause lung cancer
in humans.
To decrease elevated radon levels, Florida's legislature instructed its Department of Community
Affairs (DCA) to develop new construction standards for radon-resistant buildings, primarily slab-on-grade
constructions.
It is well-known that concrete slab is the primary barrier to radon entry. However, the extent of
its ability to permit air flow under pressure (permeability) and to permit the passage of radon without any
pressure difference (diffusivity) has not been well-determined. To establish a standard concrete mix and
its maximum radon-resistant placement, these parameters needed to be quantified and their relationship
to concrete's physical properties evaluated.
Concrete testing consists of separate permeability and diffusivity measurements and a set of
preliminary measurements to determine the size, weight, and porosity of each sample. After preliminary
tests are completed, each sample is mounted in a 4 in long section of 4 in, schedule 80 wrought steel pipe.
The concrete remains in this pipe for both the permeability and diffusivity tests.
Ten concrete samples were tested and divided into two groups. The first group was comprised
of two Rogers and Associates Engineering Corporation (RAECORP) samples that were cored from two
vi i i
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different compression test cylinders. The remaining eight samples (the second group) were cored from
four compression test cylinders (two samples from each cylinder) from the Florida Concrete and Products
Association (FC&PA). Each compression test cylinder represented one of the four general types of
concrete manufactured in Florida. The four compression test cylinders were made in Jacksonville,
Tampa, Orlando, and Miami.
After the cylinders were received, they were logged in on a sample custody form. Entries
included identifying marks. The RAECORP samples had already been reduced to the nominal testing
size, 4 in diameter by 2 in thick. The three larger FC&PA cylinders required coring and slicing to
produce the nominal sample size; the smaller, 4-in by 8-in cylinder only required slicing. Two of the
cylinders were cored on site. The remainder of the coring and slicing was performed by Lipscomb
Concrete Cutting Company of Raleigh, NC.
Sample permeability was measured with a device developed for this project. The sample holder's
open end was sealed airtight into the permeability test fixture using Mortite, a non-hardening, clay-type
sealant. To keep the sample holder sealed to the fixture, a top plate was fastened. Compressed air at 25
psi (nominal) pressurized the space enclosed by the test fixture and the bottom side of the concrete. The
pressurizing valve was closed, and a pressure-sending unit measured the pressure in the sealed volume.
As the air escaped through the concrete, the pressure decreased.
The diffusion coefficient was determined with a system developed by and purchased from
RAECORP. The method uses uranium mill tailings as a strong emitter of radon. The tailings are in a
30-gal drum with a fitting built into the lid, which accommodates the sample holder. The sample holder
is mounted in the fitting, and the detector assembly is mounted on top of the holder. After the
background count rate is measured, the valve between the drum of radon gas and the bottom surface of
the concrete sample is opened. The scalar rate meter counts and produces a paper record of the number
of counts per interval. When the count rate stops increasing, the radon gas in the drum and in the space
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above the concrete has reached equilibrium. The valve is closed, and the sample holder and detector
apparatus are disassembled.
The permeability time-versus-pressure data were analyzed by software written for this permeabil ity
determination method. The software also provided the automatic data collection system. Usually, data
was collected from the pressure sender every 10 sec. Then, six of the data points were averaged to
produce a raw data point every 1 min. This could be varied; for some of the high permeability concrete
samples, raw data points were saved each second with no averaging. The sampling technique allowed
more data to be collected and improved the standard deviation.
The physical parameters of the test (air temperature, sample thickness, sample diameter, and
volume under pressure) were used to calculate the permeability coefficient. The software requested the
data as measured, then converted them to the appropriate units. The errors in each parameter were used
to determine an estimated standard deviation for the calculated permeability coefficient. The results were
written to a data file in a format suitable for printing.
RAECORP software was used to determine the diffusion coefficient. The software uses 10 pairs
of data points from the breakthrough region of the alpha activity data. For this work, 10 percent offsets
from the baseline and the equilibrium level were used to determine the breakthrough region.
Within this region, 10 data points spaced evenly in log time were selected. The next highest
adjacent data point was used as the second data point of the pair. The first data point of the pair was used
to calculate the diffusion coefficient. The second data point was used to estimate the standard deviation
of the diffusion coefficient. A description of the software and the analysis is in DOE Report No.
NUREG/CR-2875. Appendix E contains a sample of the output. The permeability and diffusion
coefficients are graphically illustrated in Figures 1 and 2.
The permeability coefficients for Samples 2a and 2b are very high because of defects in the
concrete. The air seemed to flow primarily from a set of pores near the center. It is possible that only
x
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a few through-connected pores were responsible for the increased permeability, and the remainder of the
sample had a much lower permeability. Even if that were the case, a distribution of such pores in a slab
would significantly alter the slab's overall effective permeability.
xi
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*E*17*
5
MS «—¦
Is
• (O
u
a c-
OQ 01 2a 2b 3a 3b 4a 45 5a 5b
StrroulO
Figure 2, Bulk diffusion coefficients.
xn
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However, Sample 2 does not deviate from the range of the other samples in the diffusivity graphs.
Sample 4, however, is higher in both the pore space and bulk coefficients.
The data quality for this project met all the data quality objectives listed in an EPA approval
Quality Assurance Project Plan (QAPP). All 10 samples were collected and analyzed (except for the
density on samples C000 and C001) and the results are acceptable, within the limitations of this project.
The limitations of this research were that these measurements of concrete had not been performed before
on this scale, and that the permeability test system was a new method developed for this project.
Because the permeability test was a new method, there were no available data on the permeability
of concrete, and there was no test standard for calibration purposes. It is not possible to calculate the
percent difference between the actual and measured permeability values. The data collected in these tests
compare favorably (order of magnitude) with the expected permeability coefficients. The limiting factor
in the permeability test is the system leak rate. This leak rate imposes a minimum detectable limit of 10"20
m2 which is a factor of 10,000 lower than the concrete samples measured.
The objectives of Phase I of this project have been met. The permeability and diffusion
coefficients of concrete can now be measured. Compression test cylinders of concrete from the four
representative areas of Florida have been processed and analyzed. Also, the correlations of the various
physical parameters were investigated, although there were insufficient data to confidently determine any
correlations.
The most significant fault in this phase of the research was the lack of unbiased, representative
concrete slab samples. Although the compression test cylinders were intended to represent the actual
concrete mix from which the sample was drawn in accordance with the applicable American Society for
Testing and Materials (ASTM) standard, a compression test cylinder will never accurately represent an
as-poured slab because the effects of on-site water addition, finishing and curing practices, and other
procedures are not included.
xi i i
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The Phase I method of slicing cores into 2 in thick sections further removed the samples from
representing typical slab concrete. The correlation plots do indicate some trends in the data, but the lack
of reliability and representativeness of the concrete cylinders does not allow definitive correlations to be
determined. That the various physical parameters should correlate to the coefficients is evident and
reasonable, but not significantly so, based on these data. And, the cause and meaning of the Sample 2
and 4 outliers have not been determined.
Further work on this project should analyze unsliced, concrete cores from real slabs to obtain
reliable data on the mix design. Mix design data and on-site practice data are required if the ultimate
goals of this project are to be met.
A larger number of samples also would provide better, more significant data. The recommended
minimum sample is two cores from four slabs, from each of the four major areas in Florida with the mix
design data and, if possible, the on-site treatment. Additionally, one old concrete core from each of the
four areas should be collected and included in the data base as historical data. Nationwide samples should
be considered for additional support for the data base.
xiv
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SECTION 1.0
INTRODUCTION
Much of Florida's natural soil and the sand recovered from the phosphate mining/beneficiation
process there contain significant quantities of radium. Buildings constructed on these high-radium soils
have been found to contain elevated radon levels.
To decrease elevated indoor radon levels, Florida's legislature instructed its Department of
Community Affairs to develop new construction standards for radon-resistant buildings, primarily
slab-on-grade constructions.
It is well-known that concrete slab is the primary barrier to radon entry. However, the extent of
its ability to permit air flow under pressure (permeability) and to permit the passage of radon without any
pressure difference (diffusivity) has not been well-determined. To establish a standard concrete mix and
its maximum radon-resistant placement, these parameters needed to be quantified and their relationship
to concrete's physical properties needed to be evaluated.
Acurex Environmental Corporation was contracted by Florida's Department of Community Affairs
(DCA) and the U.S. Environmental Protection Agency/Air and Energy Engineering Research Laboratory
(EPA/AEERL), Radon Mitigation Branch (under EPA Contract No. 68-DO-0141) to conduct research
in this area.
Primary research objectives were as follows: to establish the capability to measure concrete's
permeability and diffusivity; to measure these parameters in a small sampling of the typical types of
1
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Florida concrete; and. if possible, to correlate the physical parameters of the concrete (mix design,
porosity, surface finish, etc.) to the measured diffusion and permeability coefficients.
For this project. Acurex Environmental developed a pressurized-air system to determine
permeability. The derivation of this method is listed in Appendix A.
To measure concrete's diffusivity, Acurex Environmental used Rogers and Associates
Engineering Corporation's (RAECORP) system, as described in the Department of Energy's (DOE)
Report. No. NUREG/CR-2875.
2
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SECTION 2.0
EXPERIMENTAL PROCEDURES
Concrete testing consists of separate permeability and diffusivity measurements and a set of
preliminary measurements to determine the size, weight, and porosity of each sample. After
preliminary tests are completed, each sample is mounted in a 4 in long section of 4 in, schedule 80
wrought steel pipe. The concrete remains in this pipe for both tests.
Ten concrete samples were tested and divided into two groups. The first groups was
comprised of two RAECORP samples that were cored from two different compression test cylinders.
The remaining eight samples (the second group) were cored from four compression test cylinders (two
samples from each cylinder) from the Florida Concrete and Products Association (FC&PA). Each
compression test cylinder represented one of the four general types of concrete manufactured in
Florida. The four compression test cylinders were made in Jacksonville, Tampa, Orlando, and Miami.
Three of the four cylinders were 6-in by 12-in; the fourth cylinder was 4-in by 8-in. The
cylinder from Jacksonville was shipped directly from the manufacturer. The other three were
delivered to the FC&PA representative in Orlando before being shipped to Acurex Environmental.
The mix design data for the cylinders was provided by RAECORP for the first group, and by the
manufacturers for the second group.
After the cylinders were received, they were logged in on a sample custody form. Entries
included identifying marks. The RAECORP samples had already been reduced to the nominal testing
3
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size. 4 in diameter by 2 in thick. The three larger FC&PA cylinders required coring and slicing to
produce the nominal sample size; the smaller. 4-in by 8-in cylinder only required slicing. Two of the
cylinders were cored on site. The remainder of the coring and slicing was performed by Lipscomb
Concrete Cutting Company of Raleigh, NC.
Two samples were taken from each FC&PA cylinder: an end slice and an interior section
adjacent to the end slice.
Preliminary measurements were taken on all samples after they were cored and sliced. Sample
diameter was measured four times (45° spacing) on the top and bottom. The thickness of the samples
was measured at eight points (45° spacing) on the perimeter. Samples were weighed, and porosity was
determined by the procedure in Appendix B.
The samples were then sealed into a holder for permeability and diffusivity tests. Sample
holders were 4 in long sections of 4-in wrought steel pipe. The pipe was rough cut with a cutoff saw,
then cleaned to remove loose rust and other surface contaminants. The rough cut ends were smoothed
with a file.
Samples were centered in the pipe and held in place by a layer of Teflon-coated foam pressed
into the gap between the inside pipe wall and the sample, with one end flush with the end of the pipe.
The Teflon foam filler took up about 1-in, so the remaining space was filled with epoxy. After the
epoxy was cured, the Teflon foam packing was removed.
A concrete sample's entire side surface, then, was sealed with epoxy. This bonded the
concrete into the holder in a gas-tight seal, closing the sample's sides so that the gas flow was forced
to pass through the full volume of concrete, preventing "short-circuiting" of the flow.
Sample permeability was measured with a device developed for this project; Figure 1
illustrates the device and Appendix B explains its development. The sample holder's open end was
sealed airtight into the permeability test fixture using Mortite, a non-hardening, clay-type sealant. To
4
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keep the sample holder sealed to the fixture, a top plate was fastened. Compressed air at 25 psi
(nominal) pressurized the space enclosed by the test fixture and the bottom side of the concrete. The
pressurizing valve was closed, and a pressure-sending unit measured the pressure in the sealed volume.
As the air escaped through the concrete, the pressure decreased.
The pressure data were converted to digital format by a Keithley Metrabyte board and stored
in time series on a computer data file. The pressure-versus-time profile calculated permeability
coefficient. These data were analyzed by custom software, using the same computer system.
The diffusion coefficient was determined with a system developed by and purchased from
RAECORP. The method uses uranium mill tailings as a strong emitter of radon gas. The tailings are
in a 30-gal drum with a fitting built into the lid. which accommodates the sample holder (see
Figure 2). The sample holder is mounted in the fitting, and the detector assembly is mounted on top
of the holder. After the background count rate is measured, the valve between the drum of radon gas
and the bottom surface of the concrete sample is opened. The scalar rate meter counts and produces a
paper record of the number of counts per interval. When the count rate stops increasing, the radon gas
in the drum and in the space above the concrete has reached equilibrium. The valve is then closed,
and the sample holder and detector apparatus are disassembled. The local procedure for testing is in
Appendix B.
5
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VALVE
Figure 1. Permeability test system.
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ALPHA SCINTILLATION
Figure 2. Diffusion test system.
7
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SECTION 3.0
DATA ANALYSIS
The permeability time-versus-pressure data was analyzed by software written for this permeability
determination method. The software also provided the automatic data collection system. Usually, data
were collected from the pressure sender every 10 sec. Then, six of the data points were averaged to
produce a raw data point every 1 min. This could be varied; for some of the high permeability concrete
samples, raw data points were saved each second with no averaging. The sampling technique allowed
more data to be collected and improved the standard deviation. The software is listed in Appendix C.
The software linearized the pressure-versus-time data by scaling the dependent variable (pressure)
into the natural log of the pressure divided by the initial pressure. The first data point was used as the
initial pressure. Figure 3 presents an example of the linearized data and the regression line.
The linearized data became noisy as the pressure dropped closer to the accuracy limit of the
pressure sender. A linear least-squares regression adjusted to the scaled data provided the slope of the
line and the variance in the data.
The physical parameters of the test (air temperature, sample thickness, sample diameter, and
volume under pressure) were used to calculate the permeability coefficient. The software requested the
data as measured, then converted it to the appropriate units. The errors in each parameter were used to
determine and estimated standard deviation for the calculated permeability coefficient. The results were
written to a data file in a format suitable for printing. An example of the output is in Appendix D.
8
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0 1806.5 3613 5419.5 7226 9032.5 10839 12646 14452 16259 18065
time (s)
Figure 3. Example of linearized permeability raw data graph.
9
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RAECORP software was used to determine the diffusion coefficient. The software uses 10 pairs
of data points from the breakthrough region of the alpha activity data. For this work, 10 percent offsets
from the baseline and the equilibrium level were used to determine the breakthrough region.
Within this region, 10 data points, spaced evenly in log time, were selected. The next highest
adjacent data point was used as the second data point of the pair. The first data point of the pair was
used to calculate the diffusion coefficient. The second data point was used to estimate the standard
deviation of the diffusion coefficient. A description of the software and the analysis is in DOE Report
No. NUREG/CR-2875.
The radon diffusion coefficient in coarse sand, fine sand, 4-mm glass beads, and air was
measured to validate the procedures and the software. Table 1, listing test results, shows the calculated
diffusion coefficient, the diffusion coefficient corrected for an altitude of 120 m (a factor of 0.991), and
the expected diffusion coefficient. These values are acceptable within the 50 percent estimated error.
TABLE 1. DIFFUSION VERIFICATION TESTS
Porosity Calculated D Corrected D Expected D
0.330 7.868 x 106 7.797 x 106 5.4 x 10*
0.400 6.525 x 10* 6.466 x 10* 5.7 x 10*
0.381 6.635 x 10* 6.575 x 106 7.1 x 106
1.000 1.000 x 10s 9.910 x 10* 1.1 x 105
Coarse Sand
Fine Sand
Glass Beads
Air
10
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SECTION 4.0
QUALITY ASSURANCE
Data from this project will be used in models and assessments of radon entry into structures
and must be of known quality. A Quality Assurance Project Plan (QAPP) was prepared and approved
by the EPA/AEERL Project Officer and QA Manager. It established data objectives and described
planned measurement procedures and quality controls for performance of tests. Ten concrete samples
were collected by the EPA/AEERL Project Officer and QA Manager. All 10 samples were collected
and analyzed (except for the density on samples C000 and C001), and the results may be considered
acceptable within the limitations of the project and the QAPP. The limitations of this research were
that these measurements of concrete had not been performed before on this scale and the permeability
test system was a new method developed for this project.
The QAPP was written at the start of the project and reviewed during the course of the
project. No internal or external audits were conducted. No changes to the QAPP were required.
Proper function of the diffusion test system was verified by testing four materials with
different diffusion coefficients: air, 4mm glass beads, coarse sand, and fine sand. The results of
these tests are listed in Table 2.
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TABLE 2. COMPARISON OF DIFFUSION STANDARD RESULTS
Measured D (mA2/s) Expected D (m"2/s) Difference (%)
Air
0.000009910
0.0000110
9.9
Glass beads
0.000006575
0.0000071
7.4
Coarse sand
0.000007797
0.0000054
13.4
Fine sand
0.000006466
0.0000057
44.4
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TABLE 3. DATA QUALITY
Accuracy (%) Precision (%) Completeness (%)
Measurement
Method
Objectives
Actual
Objective Actual
Objective Actual
Pressure
Transducer
< +/- 5
(1)
< +/- 5
(3)
> 80
100
Temperature
Thermocouple
< +/- 5
(1)
< +/- 5
(3)
> 80
100
Chamber Volume
Measured
< +/- 5
(1)
< +/- 5
3.4
> 80
100
Mass
Scale
< +/- 5
(1)
< +/- 5
0.02
> 80
100
Diameter
Caliper
<+/- 10
(1)
< +/- 10
0.3
>
80
100
Area
Calculated
<+/- 20
CD
< +/- 10
0.4
>
80
100
Thickness
Caliper
<+/- 10
(1)
<+/- 10
2.2
>
80
100
Density
Calculated
< +/- 30
0)
< +/- 30
2.2
>
80
80
Diffiisivity
Calculated
< +/- 50
18-33
< +/- 50
(3)
>
80
100
Permeability
Calculated
< +/- 50
(2)
< +/- 50
3.3 - 6.3
>
80
100
(1) These values cannot be determined since there is no ability to calibrate the instruments on-site. However, the manufacturer's stated
accuracies of the instruments fall with in the stated objectives.
(2) There is no means currently available to calibrate the permeability system.
(3) These values cannot be determined since repeat measurements were not made.
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Table 3 lists data objectives for measurements, as listed in the QAPP, and the actual values
achieved from the ten samples analyzed. Because the permeability test was a new method, there were
no available data on the permeability of concrete and there was no test standard for calibration
purposes. It was not possible to calculate the percent difference between the actual and measured
permeability values. The data collected in these tests compare favorably (order of magnitude) with
the expected permeability coefficients. The limiting factor in the permeability test is the system leak
rate. This leak rate imposes a minimum detectable limit of lOe'20 m2 which is a factor of 10,000
lower than the concrete samples measured.
Although the data quality is known, the findings are not representative of typical residential
concrete slabs. The samples analyzed were cored from ASTM standard compression test specimens
and then cut into 2 in thick disks. Both the method of preparing the samples and the way the
concrete was poured/cured causes these samples to be significantly different from the residential slab.
14
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SECTION 5.0
RESULTS AND DISCUSSION
The sources of the 10 samples are listed in Table 4. The RAECORP samples were cut from
two different cylinders, and are therefore numbered differently. The remaining samples represent two
slices from the same cylinder: Sample A is the end slice and Sample B is the adjacent, interior slice.
TABLE 4. SAMPLE ID AND SOURCE
Sample ID
Concrete Source
cOOO
RAECORP
cOOl
RAECORP
c002a
Jacksonville
c002b
Jacksonville
c003a
Tampa
c003b
Tampa
c004a
Miami
c004b
Miami
c005a
Orlando
c005b
Orlando
Table 5 lists the concrete mix design data for the samples. W/C is the water-to-cement ratio
in pounds of water to pounds of total cement materials (tcm; cement plus fly ash).
15
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TABLE 5. CONCRETE MIX DESIGN DATA
ID
W/C
Cement
Fly ash
TC
M
Sand
Stone
Water
Darex
WRDA 79
cOOO
*
215
215
430
1362
1701
*
1.3
30.1
cOOl
0.61
210
210
420
1370
1701
258
1
21
c002a
0.53
360
130
490
1262
1675
258
5
25
c002b
0.53
360
130
490
1262
1675
258
5
25
c003a
0.67
285
140
425
1374
1691
283
4
15
c003b
0.67
285
140
425
1374
1691
283
4
15
c004a
0.66
330
110
440
1286
1600
291
4
16.5
c004b
0.66
330
110
440
1286
1600
291
4
16.5
c005a
0.58
310
130
440
1360
1700
258
3.1
20
c005b
0.58
310
130
440
1360
1700
258
3.1
20
*The water content for sample cOOO was not provided. Therefore, the water-to-cement ratio also is
missing.
The numbers in the table are in lb/yd3 of concrete, except for Darex and WRDA79, which are
in oz/yd3. Darex and WRDA79 are special additives that make concrete more workable and reduce
the impact of the addition of extra water on the slump of the concrete. Preliminary sample
measurements and tests were used to calculate the porosity, bulk dry density, and specific gravity, as
listed in Table 6.
The permeability and diffusion coefficients are listed in Table 7. As in Table 1, Table 7 lists
both the calculated diffusion coefficient (D) and the diffusion coefficient corrected for an altitude of
120 m (D *) with a 0.991 correction factor.
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TABLE 6. PRELIMINARY MEASUREMENT DATA
ID
Density
Porosity
Specific Gravity
cOOO
0)
0.1156
(1)
cOOl
(1)
0.198
0)
c002a
2.0934 (1,2)
0.1922
2.4061 (1,2)
c002b
2.0934 (1,2)
0.1974
2.4061 (1,2)
c003a
2.0381
0.1526
2.4052
c003b
2.0677
0.1708
2.4936
c004a
2.1443
0.1412
2.4968
c004b
2.1464
0.1411
2.499
c005a
1.963
0.1667
2.3558
c005b
2.0388
0.141
2.3734
(1) Early in the project, these data were not measured before the samples were mounted.
Obtaining accurate results is not possible after the sample is mounted.
(2) These data are from sample c002f.
TABLE 7. PERMEABILITY AND DIFFUSION COEFFICIENTS
ID
k
D pore
D bulk
D pore*
D bulk*
cOOO
2.14 x 1016
1.59 x ia7
1.84 x 10"8
1.57 x 10"7
1.82 x ia8
cOOl
7.1 x ia16
i.55 x ia7
3.06 x 10"8
i.53 x ia7
3.04 x 10"8
c002a
8.77 x 1014
i.65 x ia7
3.16 x ia8
1.63 x ia7
3.13 x ia8
c002b
4.56 x 1014
1.58 x ia7
3.1 x lO"8
1.56 x ia7
3.07 x ia8
c003a
2.04 x 1016
1.71 x 10"7
2.61 x lO"8
1.69 x ia7
2.59 x ia8
c003b
1.98 x 10'16
1.53 x 10"7
2.61 x ia8
i.5i x ia7
2.59 x ia8
c004a
1.31 x 1016
2.34 x ia7
3.35 x ia8
2.32 x ia7
3.32 x ia8
c004b
1.11 x 1016
2.72 x ia7
3.83 x ia8
2.69 x ia7
3.8 x 108
c005a
2.11 x 1016
1.56 x ia7
2.61 x ia8
1.55 x ia7
2.59 x ia8
c005b
9.38 x 1017
i.9i x ia7
2.7 x lO"8
1.89 x 10"7
2.67 x 10"8
17
-------
Permeability coefficients are in m2. Diffusion coefficients are in m2/s. The "D pore," the
diffusion coefficient corrected for the measured porosity of the concrete, assumes all the diffusive
radon transport occurs in the concrete's pore spaces.
By adjusting the diffusion coefficient for porosity, the actual diffusion coefficient for a
particular soil over a range of packing densities could be calculated from one diffusion test for the
soil. Because the "packing density" of concrete will not change, the "bulk" diffusion coefficient has
been included in this research. This lifts the requirement of accurately measuring the true, available
porosity and may correlate more closely to concrete's physical parameters. Bar graphs of the
permeability and diffusion data are presented in Figures 4, 5, and 6.
Figure 4 illustrates the significantly higher permeability of sample 2. These samples were so
permeable that when air under pressure was forced through the samples, the air stream could be heard
and felt at the concrete's upper surface. This phenomena was not noted for any other sample. The
air seemed to flow primarily from a set of pores near the center. It is possible that only a few
through-connected pores were responsible for the increased permeability, and the remainder of the
sample had a much lower permeability. Even if that were the case, a distribution of such pores in a
slab would significantly alter the slab's overall effective permeability.
However, Sample 2 does not deviate from the range of the other samples in the diffusivity
graphs of Figures 5 and 6. Sample 4, however, is higher in both the pore space and bulk
coefficients. Appendix F contains the correlation plots for the permeability and diffusion
coefficients. Various correlations between permeability/diffusion coefficients and the mix design
parameters were examined, but there was insufficient data to confirm any statistically significant
correlations. In general, the permeability correlation plots indicate some relationship between the mix
design parameters, with the exception of Sample 2 which was a significant outlier in all plots. The
permeability versus cement content plot in this study tends to indicate a relationship, as might be
18
-------
expected, but the relationship cannot be statistically justified. The diffusion coefficient plots also
indicate some trends, without any significant outlier.
19
-------
1E-13
1E-14
Cvj
E 1E-15
1E-16
1E-17
00 01 2a 2b 3a 3b 4a 4b 5a 5b
Sample Id
Figure 4. Permeability coefficients.
20
-------
00 01 2a 2b 3a 3b 4a 4b 5a 5b
Sample id
Figure 5. Bulk diffusion coefficients.
21
-------
CO ^
cvl •>
< LU
_E, o
* w
Q) 0
o E
5-b
00 01 2a 2b 3a 3b 4a 4b 5a 5b
Sample Id
Figure 6. Pore space diffusion coefficients.
22
-------
SECTION 6.0
CONCLUSIONS
The objectives of Phase I of this project have been met. The permeability and diffusion
coefficients of concrete can now be measured. Compression test cylinders of concrete from the four
representative areas of Florida have been processed and analyzed. The correlations of the various
physical parameters were investigated, although there were insufficient data to confidently determine
any correlations.
The most significant fault in this phase of the research was the lack of unbiased,
representative concrete slab samples. Although the compression test cylinders were intended to
represent the actual concrete mix from which the sample was drawn (in accordance with the
applicable ASTM standard), a compression test cylinder will never accurately represent an as-poured
slab because the effects of on-site water addition, finishing and curing practices, and other procedures
are not included.
The Phase I method of slicing cores into 2 in thick sections further removed the samples from
representing typical slab concrete. The correlation plots do indicate some trends in the data, but the
lack of reliability and representativeness of the concrete cylinders does not allow definitive
correlations to be determined. That the various physical parameters should correlate to the
coefficients is evident and reasonable, but not significantly so, based on these data. Also, the cause
and meaning of the Sample 2 and 4 outliers has not been determined.
This work has shown that the porous nature of the concrete slab can allow greater transport of
radon into a house than desired. Concrete slabs may require a sub-slab vapor/moisture barrier to
limit radon infiltration to acceptable levels.
23
-------
SECTION 7.0
RECOMMENDATIONS
Further work on this project should analyze unsliced, concrete cores from real slabs to obtain
reliable data on the mix design. Mix design data and on-site practice data are required if the ultimate
goals of this project are to be met.
A larger number of samples also would provide better, more significant data. The
recommended minimum sample is two cores from four slabs, from each of the four major areas in
Florida with the mix design data and, if possible, the on-site treatment. Additionally, one old
concrete core from each of the four areas should be collected and included in the data base as
historical data. Nationwide samples should be considered for additional support for the data base.
24
-------
REFERENCES
Kalkwarf, D.R., Nielson, K.K., Rich, D.C., and Rogers, V.C., "Comparison of Radon
Diffusion Coefficients Measured by Transient-Diffusion and Steady-State Laboratory
Methods," NUREG/CR-2875, PNL-4370, RAE-18-3
BIBLIOGRAPHY
1. Nielson, K.K., and Rogers, V.C., "Radon Entry into Dwellings Through Concrete
Floors," In: Proceedings: The 1991 International Symposium on Radon and Radon
Reduction Technology, Volume 1, EPA-600/9-91-037a (NTIS PB92-115351),
November 1991.
2. ACRES International Corporation, "Radon Entry through Cracks in Slab-on-Grade,"
Final Report, Florida Department of Community Affairs Contract No.
90RD-70-14-00-22-007 (1990).
3. Poffijn, A., Berkvens, P., Vanmarcke, H., and Bourgoingie, R., "On the Exhalation and
Diffusion Characteristics of Concrete," Radiation Protection Dosimetry, Vol. 24, 203-206
(1988).
25
-------
APPENDIX A
PERMEABILITY DATA ANALYSIS DERIVATION
From the Ideal Gas Law:
PV = nRT
The equations for the any two pressures of the enclosed space are:
Pyt = n,RT
P2Ve = nJiT
Where:
P,,P2 = pressure
n„n2 = number of moles of gas
Vc = enclosed volume
Solving for the change in pressure in terms of the change in the number of moles of air contained
the volume:
Pt-P,-AP- (/>, - njE
AD A
AP = An —
C
V
An = AP-L
RT
Because the volume of air at atmospheric pressure is needed, the Ideal Gas Law is used again to
relate the number of moles to volume:
P^ V, = A nRT
aim out
V
= AP-LRT
RT
= A PV.
Where:
Palm = atmospheric pressure
vout = volume of An moles at P*
26
-------
This yields a relationship between the pressure change in the enclosed volume and the volume of air
which permeated the concrete: (1)
V
V, = —LA P
cut p
atn
This relationship is valid within 0 to 25 psig, the range used in testing.
From Darcy's Law, the volume of a gas per unit time as a function of the physical parameters
of the system and the permeability coefficient is:
AV = rAP
At fiT
Substituting equation (1) into this equation for the volume of gas leads to:
-AP Vc = kaP
Paon V-T
APP
- AP = K — At
HTVC
This difference equation is transformed into a differential equation and solved by separation of
variables:
dP m _K^n^_dt
P VeliT
In (P) = + q
C; = constant of integration
27
-------
This yields a functional form of the pressure inside the enclosed volume as a function of time:
P(t) = PDe
This decaying exponential form can be converted into a linear form:
In
P(f)
-K.
PA
i
VeliT
In this form, the permeability coefficient is related to the slope of the line:
slope = -K%4
VC»T
A linear, least-squares regression fit to the data provides the slope of the line. The permeability
then related to the slope of the line and the physical parameters of the system:
{slope) VcfiT
PA
cum
28
-------
The estimated standard deviation of the permeability is calculated by summing in quadrature the
variances of the individual factors divided by the square of their value:
3 slope
(slope)2
K +£r + £
x2 T A2
K2
The variance in the slope of the regression line is calculated from the spread in the data. The
variance in the thickness and area factors is estimated from the standard deviation in the
measurements of the sample. The standard error in the chamber volume is estimated at 15 ml; a
1 °C error is assumed for the variation in the viscosity of the air.
29
-------
APPENDIX B
MEASUREMENT PROCEDURES
Procedure Page
Porosity Estimation 31
Permeability Test 32
Diffusion Test 34
30
-------
POROSITY ESTIMATION PROCEDURE
1. Measure and weigh the concrete sample "as is."
2. Place in the vacuum for two hours.
3. Add hot tap water.
4. Keep it under the vacuum for 30 min and check for bubbles.
5. Remove the vacuum and leave the sample in water for 30 min.
6. Remove the sample from the water.
7. Shake off excess water and weigh the sample.
8. Place the sample in a vacuum oven at 220 °F to 250 °F for 18 hours.
9. Remove the sample from the oven and weigh.
10. Porosity = (wet weight-dry weight)/gross volume of the sample.
31
-------
PERMEABILITY TEST PROCEDURE
1. Ensure the sealing surface on the base is clean and the valve is open.
2. Put a layer of Mortite on the bottom of the sample holder.
3. Center the sample holder on the base and press it in place.
4. Assemble by setting the top plate on first, followed by a spring washer, flat washer and a nut
on each threaded post.
5. Connect the analog output line to the computer.
6. Connect the power to the pressure transmitter.
7. Type "pb < return> " at the dos prompt to start the software.
8. Type"l < return>" to select the collect data option.
9. Enter the number of intervals to be averaged.
10. Enter the number of seconds per interval.
11. Enter the filename into which the data will be written.
12. Enter the sample identification.
13. Press the space bar to verify the pressure data reads 2048 or 2049.
14. Turn on the air and connect the house air to the input.
15. Press the space bar, verify the pressure transmitter reading and pressure gauge reading are about
same.
16. Allow 1 min for the pressure to equalize.
17. Close the valve and press the " —" key to begin collecting data.
18. Disconnect the air hose and turn off air.
32
-------
19. Record the temperature at the top of the concrete.
20. After the software stops collecting data, open the valve.
21. Run the data analysis software.
22. Disconnect the power and data cables.
33
-------
DIFFUSION TEST PROCEDURE
1. Place the sample holder into the drum.
2. Open the valve on the detector housing.
3. Press the detector housing onto the sample holder.
4. Attach the bag to the valve.
5. Attach the high voltage line to the detector.
6. Attach the battery lines.
7. Turn on the Ludlum scalar rate meter.
8. Set high voltage to 3.00 and lock it.
9. Note date, time, and detector id on the paper tape.
10. Note sample id, sample interval, and bkg on the paper tape.
11. Turn on the recycle switch.
12. Collect background for at least one hour.
13. Turn off the recycle switch and wait for the cycle to finish.
14. Advance the paper and mark the time.
15. Open the drum valve and turn on the recycle switch.
16. Wait for the system to reach equilibrium.
17. Turn off the recycle switch and wait for the cycle to finish.
18. Close the drum valve, advance the paper, and mark the date and time.
34
-------
19. Turn high voltage to 0.000.
20. Turn off the Ludlum scalar rate meter.
21. Disassemble the detector, high voltage line, battery leads, and sample holder.
22. Leave parts on top of the drum with the exhaust fan operating.
35
-------
APPENDIX C
PERMEABILITY SOFTWARE
10 ' permprog version 2.0
20 ' changes language used when requesting input
30 ' modifies timing loop to do a better job in checking for day changes
40 ' modifies timing loop to do a better job in sampling at the proper interval
SO ' corrects calculation in pressure to use gauge pressure
60 ' corrects error, in analysis section to use ln(P/Po) rather than ln(P)
70 ' corrects error in analysis for conversion from micropoise to Pa-s
80 CLS
90 DIM TIM(65), ADC % (65)
100 CLOSE
110 PRINTrPRINT
120 PRINT "this program collects the data and analyzes the results"
130 PRINT : PRINT
140 INPUT "type 1 to collect data, 2 to analyze data, or 3 to exit: CHOICE%
150 IF CHOICE % = 1 THEN GOTO 240
160 IF CHOICE%=2 THEN GOTO 1410
170 IF CHOICE%=3 THEN GOTO 2990
180 GOTO 140
190 '
200 '
210 ' this begins the code to collect data from the metrabyte board
220 '
230 '
240 DAY=0
250 CLS
260 '
270 'specify base address, channel to be sampled, and data filename
280 BASADR% =&H300
290 MA%=0
300 INPUT "number of sampling intervals to be averaged: INTERVALS
310 PRINT
320 INPUT "number of seconds per interval: ".INTLENGTH
330 PRINT
340 MIDINTERVAL=INT((INTERVALS/2) + .5)
350 PRINT
360 FILES
370 INPUT "enter filename for the data from this run: ".FILENAMES
380 INPUT "enter sample number being tested: SAMPLES
390 '
400 'initialize the metrabyte board and set the chanel
410 OUT BASADR% +2,MA%
420 '
430 ' open data file and set file header
440 OPEN FILENAMES FOR OUTPUT AS #1
450 PRINT #1, "data file for sample number ";SAMPLE$;" - ";DATE$;" ";TIME$
460 PRINT #1, "each entry is an average of
470 PRINT #1, INTERVALS;" measurements sampled "
36
-------
480 PRINT #1, INTLENGTH;" seconds apart"
490 CLOSE #1
500 '
510 ' display initial data upon keyboard request
520 '
530 ' press " to begin collecting data
540 ' press any other key to get a one-time readout of the pressure sender
550 '
560 PRINT "press " to begin collecting data"
570 PRINT
580 PRINT "press any other key to get a one-time readout of the pressure sender"
590 PRINT
600 '
610 KB$=INKEY$:IF KB$ = "" THEN 610 ELSE IF KB$=""" THEN GOTO 890 ELSE GOTO 620
620 '
630 ' check the date and time before collecting the data
640 DT1$= DATES: TM1$= TIMES: TIM 1= TIMER
650 '
660 ' request a/d conversion
670 OUT BASADR% + 1,0
680 1
690 ' check to see if a/d conversion is complete
700 IF INP(BASADR% + 2)> =128 GOTO 700
710 1
720 ' check the date and time after the conversion is complete
730 DT2$= DATES: TM2$= TIMES: TIM2=TIMER
740 '
750 ' convert output bytes to number, voltage, and pressure
760 XL% = INP(B AS ADR %): XH % = INP(B AS ADR % +1)
770 DAT% = 16*XH% +XL%/16
780 V=DAT % *(10/4096): V=V-5
790 PRESS=V*6
800 '
810 ' print out data to screen
820 '
830 PRINT DT1S;" ";TM1$;" ";TIM1;" — ";DT2$;" ";TM2$;" ";TIM2
840 PRINT "dat%= ";DAT%;" volts = ";V;"pressure= ";PRESS
850 PRINT
860 '
870 GOTO 610
880 1
890 '
900 ' this begins the code to collect the data and save it to disk
910 '
920 CLS
930 PRINT " press & to end the run and return to the main menu"
940 PRINT
950 PRINT "data for sample number ";SAMPLE$;" - ";DATE$;" ";TIME$
37
-------
960 PRINT
970 CK1= TIMER
980 TIM(0)=TIMER+DAY
990 WHILE INKEY$ < >
1000 FOR 1= 1 TO INTERVALS
1010 CK2=TIMER
1020 IF CK2 =128 GOTO 1120
1130 '
1140 TIMB=TIMER+DAY
1150 TIM(I)=(TIMA+TIMB)/2
1160 XL% = INP(B AS ADR %): XH % =INP(BASADR% +1)
1170 DAT% = 16*XH% + XL%/16
1180 'V=DAT%*(10/4096):V=V-5
1190 'PRESS=V*6
1200 ADC%(I)=DAT%
1210 '
1220 NEXT I
1230 TIMEAV=TIM(MIDINTERVAL)
1240 ADCSUM=0
1250 FOR AV= 1 TO INTERVALS:ADCSUM=ADCSUM+ADC%(AV):NEXT
A V: ADC A V=ADCSUM/INTERV ALS
1260 PRESSAV=(ADCAV*(10/4096)-5)*6
1270 OPEN FILENAMES FOR APPEND AS #1
1280 PRINT #1, TIMEAV,ADCAV,PRESSAV
1290 CLOSE #1
1300 PRINT TIMEAV,ADCAV,PRESSAV
1310 PRINT
1320 TIM(0)=TIM(INTERVALS)
1330 IF PRESSAV < = .1 THEN GOTO 1350
1340 WEND
1350 '
1360 GOTO 100
1370 '
1380 '
1390 '
1400 '
1410 CLS
1420 PRINT
38
-------
1430 PRINT "this program analyzes the time vs. pressure data and
1440 PRINT
1450 PRINT "computes the permeability coefficient"
1460 PRINT
1470 FILES
1480 INPUT " filename of data for analysis: ", INFILE$
1490 PRINT
1500 INPUT "filename for output of analysis: OUTFILE$
1510 PRINT
1520 IF INFILE$=OUTFILE$ THEN GOTO 1500
1530 OPEN INFILE$ FOR INPUT AS #1
1540 OPEN OUTFILE$ FOR OUTPUT AS #2
1550 REM this program assumes a four-line header
1560 LINE INPUT #1, HEADER 1$
1570 LINE INPUT #1, HEADER2$
1580 LINE INPUT #1, HEADER3$
1590 LINE INPUT #1, HEADER4$
1600 INPUT #1, TIME0#, ADC0#, P0#
1610 N#= 1:SUMX#=0:SUMXY#=0:SUMX2#=0
1620 SUMY#=0:SUMY2#=0: ADCNOT#=ADCO0-2O48
1630 WHILE NOT EOF(l)
1640 INPUT #1, TIME#, ADC#, PPSI#
1650 LNPP0#=LOG((ADC#-2048)/ADCNOT#)
1660 TPRIME#=TIME#-TIME0#
1670 SUMX#=SUMX#+TPRIME#
1680 SUMY#=SUMY#+LNPP0#
1690 SU MXY#=SU MXY#+TPRIME#*LNPP0#
1700 SUMX2#=SUMX2#+TPRIME#*TPRIME#
1710 SU MY2#=SU MY2#+LNPP0#*LNPP0#
1720 N#=N#+1
1730 WEND
1740 DELTAT#=TPRIME#
1750 R1 #=N#*SUMXY#-SUMX#*SUMY#
1760 R2#=SQR((N#*SUMX2#-SUMX#*SUMX#)*(N#*SUMY2#-SUMY#*SUMY#))
1770 R#=R1#/R2#
1780 SLOPE#=(N#*SUMXY#-SUMX#*SUMY#)/(N#*SUMX2#-SUMX#*SUMX#)
1790 INTCPT# = (SUMX2#*SU M Y#-SUMX#*SU MXY#)/(N#*SUMX2#-SUMX#*SUMX#)
1800 INPUT " sample holder dead volume (ml): ",SHDV#
1810 VC#=SHDV#/999972!-.00001276010464#
1820 INPUT " air temperature (deg C): ",ROOMTEMP#
1830 MU#=(176.4+.35*ROOMTEMP#)*.0000001
1840 INPUT " sample thickness (in): ",THICKIN#
1850 THICK#=THICKIN#*.0254
1860 INPUT " sample diameter (in): SAMPLEDIAIN#
1870 SAMPLEDIA#=SAMPLEDIAIN#* .0254
1880 INPUT " error in sample thickness (in): SIGMATHIN#
1890 SIGMATH#=SIGMATHIN#*.0254
1900 INPUT " error in sample diameter (in): SIGMADIAIN#
39
-------
1910 SIGMADIA#=SIGMADIAIN#* .0254
1920 AREA#=3.1415926535#*SAMPLEDIA#A2/4!
1930 CP A#= 101325#
1940 PERM1#=-1 *SLOPE#*(SHDV#-12.75974736#)*THICKIN#/(SAMPLEDIAIN#A2)
1950 PERM2#=((ROOMTEMP#*.001984126984#)+1)*8.727111611D-15
1960 PERMCOEFF#=PERM 1 #*PERM2#
1970 1
1980 '
1990 REM calculate the standard error in slope based on the residuals
2000 CLOSE #1
2010 OPEN INFILE$ FOR INPUT AS #1
2020 LINE INPUT #1, TRASH$
2030 LINE INPUT #1, TRASH$
2040 LINE INPUT #1, TRASH$
2050 LINE INPUT #1, TRASH$
2060 INPUT #1, TIME0#, ADC0#, P0#
2070 ADCNOT#=ADC0#-2048
2080 RESIDSUM#=(-1 *INTCPT#)A 2
2090 N#= 1
2100 WHILE NOT EOF(l)
2110 INPUT #1, TIME#, ADC#, PPSI#
2120 LNPP0#=LOG ((ADC#-2048)/ADCNOT#)
2130 TPRIME#=TIME#-TIME0#
2140 N#=N#+1
2150 RESIDSUM#=RESIDSUM#+(LNPP0#-(INTCPT#+SLOPE#*TPRIME#))*2
2160 WEND
2170 SIGMA2B1#=N#*RESIDSUM#/((N#-2)*(N#*SUMX2#-SUMX#*SUMX#))
2180 REM now calculate the total variance and standard deviation in permcoeff#
2190 SIGMA2VC#=(15/999972!)"2
2200 SIGMA2AREA#=(3.1415926535#*SAMPLEDIA#/2)A2*SIGMADIA#A2
2210 SIGMA2MU#=(3.5E-08)A2
2220 TERM 1 #=SIGMA2B1 #/SLOPE# A 2
2230 TERM2#=SIGMA2VC#/VC#A 2
2240 TERM3#=SIGMA2MU#/MU#A2
2250 TERM4#=SIGMATH#A2/THICK#A2
2260 TERM5#=SIGMA2AREA#/AREA#A 2
2270 VARLANCEK#=(TERM 1 #+TERM2#+TERM3#+TERM4#+TERM5#) *PERMCOEFF#A 2
2280 SIGM AK#=SQR(VARI AN CEK#)
2290 '
2300 PRINT #2, HEADER 1$
2310 PRINT #2, HEADER2$
2320 PRINT #2, HEADER3$
2330 PRINT #2, HEADER4$
2340 PRINT #2,:PRINT #2,
2350 PRINT #2, " number of datapoints = ";N#
2360 PRINT #2, " total data collection time = ";DELTAT#; M(s)n
2370 PRINT #2, " fit correlation coefficient = ";R#
2380 PRINT #2, " slope = ";SLOPE#; "(sA-l)n
2390 PRINT #2, " intercept = ";INTCPT#; ""
40
-------
2400 PRINT
2410 PRINT
2420 PRINT
2430 PRINT
2440 PRINT
2450 PRINT
2460 PRINT
2470 PRINT
2480 PRINT
2490 PRINT
2500 PRINT
2510 PRINT
2520 PRINT
2530 PRINT
2540 PRINT
2550 PRINT
2560 PRINT
2570 PRINT
2580 PRINT
2590 PRINT
2600 PRINT
2610 CLS
2620 PRINT:
2630 PRINT
2640 PRINT
2650 PRINT
2660 PRINT
2670 PRINT
2680 PRINT
2690 PRINT
2700 PRINT
2710 PRINT
2720 PRINT
2730 PRINT
2740 PRINT
2750 PRINT
2760 PRINT
2770 PRINT
2780 PRINT
2790 PRINT
2800 PRINT
2810 PRINT
2820 PRINT
2830 PRINT
2840 PRINT
2850 PRINT
#2,:PRINT #2,
#2, " sample holder dead volume = ";SHDV#; " (ml)"
#2,
#2,
#2,
n,
#2,
n,
n,
n,
#2,
n,
#2,
n,
n,
n,
chamber volume = ";VC#; " (mA3)"
room temperature = ";ROOMTEMP#; " (deg C)"
air viscosity = " (Pa-s)"
sample thickness = ";THICKIN#; " (in)"
sample thickness = ";THICK#; M (m)"
sample diameter = ";SAMPLEDIAIN#; " (in)"
sample diameter = ";SAMPLEDIA#; " (m)"
sample area = ";AREA#; " (m'2)"
term 1 (slope) = ";SQR(TERM 1 #*PERMCOEFF#*2); " (mA2)"
term 2 (volume) = ";SQR(TERM2#*PERMCOEFF#A2); " (nT2)"
term 3 (viscosity) = ";SQR(TERM3#*PERMCOEFFr2); " (m'2)"
term 4 (thickness) = ";SQR(TERM4#*PERMCOEFF#A2); " (m'2)"
term 5 (sample area) = ";SQR(TERM5#*PERMCOEFF#A2); " (m'2)"
#2, :PRINT#2,
#2, " permeability coefficient = ";PERMCOEFF#; " (m'2)"
#2, " standard deviation = ";SIGMAK#; " (mA2)"
#2, " v 2.0"
ni, CHR$(12)
PRINT
HEADER 1$
HEADER2$
HEADER3$
HEADER4$
PRINT
number of datapoints = ";N#
total data collection time = ";DELTAT#; "(s)"
fit correlation coefficient = ";R#
slope = ";SLOPE#; "(s"-l)"
intercept = ";INTCPT#; ""
PRINT
sample holder dead volume = ";SHDV#; " (ml)"
chamber volume = ";VC#; " (m"3)"
room temperature = ";ROOMTEMP#; " (deg C)"
air viscosity = " (Pa-s)"
sample thickness = ";THICKIN#; " (in)"
sample thickness = ";THICK#; " (m)"
sample diameter = ";SAMPLEDIAIN#; " (in)"
" sample diameter = ";SAMPLEDIA#; " (m)"
sample area = ";AREA#; " (m"2)"
term 1 (slope) = ";SQR(TERMl#*PERMCOEFF#A2); " (mA2)"
term 2 (volume) = ";SQR(TERM2#*PERMCOEFF#*2); " (m'2)"
41
-------
2860 PRINT " term 3 (viscosity) = ";SQR(TERM3#*PERMCOEFFr2); " (m"2)"
2870 PRINT " term 4 (thickness) = ";SQR(TERM4#*PERMCOEFF#"2); " (nT2)"
2880 PRINT " term 5 (sample area) = ";SQR(TERM5#*PERMCOEFFr2); " (mA2)"
2890 PRINT:PRINT
2900 PRINT " permeability coefficient = ";PERMCOEFF#; " (m*2)"
2910 PRINT " standard deviation = ";SIGMAK#; " (m*2)H
2920 PRINT " v 2.0"
2930 PRINT:PRINT
2940 CLOSE
2960 GOTO 120
2970 '
2980 '
2990 ' the end
3000 CLOSE
3010 SYSTEM
3020 END
42
-------
APPENDIX D
SAMPLE PERMEABILITY DATA
Data as collected by system:
data file for sample number s-c002a - 06-27-1991 03:14:47
each entry is an average of
1 measurements sampled
3 seconds apart
11910.15
3111
15.57129
11914.3
2760
10.42969
11918.41
2517
6.870117
11922.54
2352
4.453125
11926.63
2221
2.53418
11930.75
2145
1.420899
11934.87
2097
.7177735
11939.01
2069
.3076172
11943.13
2059
.1611328
11947.25
2051
4.394532E-02
43
-------
Output of the analysis program:
data file for sample number s-c002a - 06-27-1991 03:14:47
each entry is an average of
1 measurements sampled
3 seconds apart
number of datapoints = 10
total data collection time = 37.10000000000036 (s)
fit correlation coefficient = -.9861110549167373
slope = -.1524115350996284 (sA-l)
intercept = .4155344068874098
sample holder dead volume = 380 (ml)
chamber volume = 3.672505356579283D-04 (mA3)
room temperature = 25 (deg C)
air viscosity = 1.851499959111536D-05 (Pa-s)
sample thickness = 2.11775 (in)
sample thickness = 5.379084934992716D-02 (m)
sample diameter = 3.4565 (in)
sample diameter = 8.779509893897922D-02 (m)
sample area = 6.053832862289963D-03 (m*2)
term 1 (slope) = 5.411665221832425D-15 (mA2)
term 2 (volume) = 3.711985954427575D-15 (mA2)
term 3 (viscosity) = 1.717946670177655D-16 (mA2)
term 4 (thickness) = 1.345302320831861D-15 (mA2)
term 5 (sample area) = 2.265871501088184D-16 (mA2)
permeability coefficient = 9.087937855083903D-14 (mA2)
standard deviation = 6.704897738049699D-15 (mA2)
v 2
44
-------
APPENDIX E
SAMPLE DIFFUSIVITY DATA
•FITS DIFFUSION CODE*
INPUT DATA SUMMARY
DATA SET FOR THIS RUN IS C002A
LOW SOURCE CONCENTRATION RANGE (75-525 PCI/CC)
NUMBER OF TERMS FOR SUMMATIONS IS 50
CONVERGENCE CRITERION FOR SUMS IS 0.00010
COLUMN LENGTH IS 5.080 CM
DWELL TIME IS 10.0 MINUTES
DRY DENSITY IS 2.155 GM/CC
POROSITY IS 0.192
NUMBER OF DATA POINTS IS 10
DATA
POINT NO.
TIME IN
UNITS OF DT
COUNT
RATE 1
COUNT
RATE 2
1
16
6.241E+04
6.805E+04
2
22
9.647E+04
1.019E+05
3
28
1.305E+05
1.347E+05
4
38
1.794E+05
1.843E+05
5
50
2.328E+05
2.366E+05
6
66
2.939E+05
2.974E+05
7
88
3.623E+05
3.654E+05
8
118
4.319E+05
4.326E+05
9
156
4.953E+05
4.956E+05
10
200
5.460E+05
5.464E+05
D = 3.16E-04
C =
2.25E+02
ST DEV =
2.796E+04
D = 3.16E-04
C =
2.25E+02
ST DEV =
2.796E+04
COUNTS DETECTED IN DWELL TIME = 10. MINUTES
CHAN 1 CHAN 2
16 22
************** ******** ********
RADON CALC. 1.09E+04 2.03E+04
POLONIUM CALC. 2.54E+04
2.21E+05
BISMUTH CALC.
2.31E+05
TOTAL CALC. 4.50E+04 9.47E+04
TOTAL EXP. 6.24E+04 9.65E+04
DIFF. COEF. 1.99E-03 1.72E-03
RN CONC PCI/CC 2.37E+01
1.94E+02
CHANNEL NUMBER
CHAN 3 CHAN 4 CHAN 5
28 38 50
******** ******** ********
2.91E+04 4.18E+04 5.37E+04
4.84E+04 7.04E+04 1.02E+05
CHAN 6 CHAN 7 CHAN 8 CHAN 9 CHAN 10
66
********
88
********
118
********
156
********
200
********
6.52E+04 7.54E+04 8.31E+04 8.76E+04 8.96E+04
1.32E+05 1.60E+05 1.86E+05 2.05E+05 2.16E+05
8.65E+03 2.61E+04 4.82E+04 8.47E+04 1.21E+05 1.56E+05 1.88E+05 2.11E+05 2.25E+05
1.48E+05
1.31E+05
1.54E-03
4.38E+01
2.28E+05
1.79E+05
1.36E-03
6.30E+01
3.06E+05
2.33E+05
1.22E-03
9.03E+01
3.82E+05
2.94E+05
1.12E-03
1.16E+02
4.49E+05
3.62E+05
1.05E-03
1.41E+02
5.00E+05
4.32E+05
9.62E-04
1.63E+02
5.29E+05
4.95E+05
9.62E-04
1.80E+02
5.42E+05
5.46E+05
9.28E-04
1.89E+02
RADON SOURCE CONCENTRATION IS 225.0 PCI/CC
THE DIFFUSION COEFFICIENT IS 1.645E-03 CM2/SEC +- 5.25E-04 = 31.9%
STANDARD DEVIATION IN COUNT RATES FOR COMPOSITE D IS 2.80E+04
THERE WERE 10 POINTS USED TO CALCULATE THE STANDARD DEVIATION OF THE DIFFUSION COEFFICIENT
45
-------
APPENDIX F
CORRELATION PLOTS
46
-------
00
c\i
CD
oj
Tj-
cvi
CM 45 N
CM 9] LU
E 2
"flT 0/3
E CD
o F
¦ cm a«
¦a C-
00
1
CD
1111—r
11 1 i—1—r
111 n 1 1 1
CD
UJ
CO
LLI
111 11 1 1 r
LLi
ID
111
h~
LLi
(SvUJ) M
47
-------
1E-13g
1E-1 4e
1 E-15=
1 E-1 6e
1E-17
1.5
2.5 3
d bulk (mA2/s)
(Times 10E-8)
-------
1E-13=r
1E-14=
1 E-15=
1 E-16=
1E-17-
1.4 1.6 1.8
2 2.2
d pore * (mA2/s)
(Times 10E-7)
-------
1E-13g
1E-14=
1E-15=
1E-16=
1E-17
1.8
2.6 2.8 3
d bulk * (mA2/s)
(Times 10E-8)
-------
1E-13g
1E-14=
1E-15=
1 E-16
1E-17
0 0.1 0.2
0.3 0.4
water:cement (tcm)
-------
1E-13 =
1E-14:
CM
E 1E-15;
XL
1E-16:
I
1E-17
"i —i r
0.11 0.12 0.13 0.14
015 016 017 018 019 0.2
porosity
-------
1E-13=r
1E-1 4e
1E-15=
1 E-163
1 E-17H 1 r-
200 220 240
li
260 280 300 320 340 360
cement (lbs/yard)
-------
1E-13
1E-17
100
140 160 180 200 220
flyash (lbs/yard)
-------
1E-13=
1E-17
420 430 440 450 460 470 480 490
total cementitious materials (lbs/yard)
-------
1 E-13=r
1E-U-
1E-15=
1E-16=
1 E-17
1260 1280
1300 1320 1340 1360 1380
sand (lbs/yard)
-------
ic-io;
1E-14=
1E-15=
1 E-16^'
1E"117600 1620 1640 1660 1680 1700
stone (lbs/yard)
-------
r
1E"13q
U\
00
1E-17
100 150 200
water (lbs/yard)
300
-------
1E-13a
1E-1 4e
CM
E 1 E-15=
¦—• ii
jx.
1 E-16=
1E-17^ 1 r
1 1.5 2
2.5 3 3.5
darex (oz/yard)
-------
1E-13g
1E-14e
1E-15e
1E-16;
1E-17
14
20 22 24 26 28 30 32
wrda79 (oz/yard)
-------
1E-06
c3
<
E,
£
o
Q_
Q
1E-07-1 . ¦ -77
0.11 0.12 0.13 0.14
0.15 0.16 0.17 0.18 0.19
porosity
-------
1E-06
c3
<
E
S>
o
Q.
Q
1E-07
0
0.6
water:cement
-------
r
1E-06
On
c3
<
E,
£
o
Q.
Q
1E-07
200 220 240
260 280 300 320 340 360
cement (lbs/yard)
-------
1E-06
<
E,
£
o
Q_
Q
1E-07H r-
100 120
140 160 180 200
flyash (lbs/yard)
-------
r
1E-06
0\
Ui
c3
<
E
£
o
Q.
Q
7 . — 1 1 1— r - r
420 430 440 450 460 470 480 490
total cementitious materials (lbs/yard)
-------
1E-06
<
E.
9>
o
Q.
1 E.07-J , , , , ,
1260 1280 1300 1320 1340 1360 1380
sand (lbs/yard)
-------
1E-07H 1 1 1 1 1—
1600 1620 1640 1660 1680 1700
stone (lbs/yard)
-------
1E-06
<
EE.
CD
o
Q_
Q
1E-07H . . r-
250 255 260 265
270 275 280 285 290 295 300
water (lbs/yard)
-------
1E-06
<
E.
2
O
Q.
Q
1E-07
1
1.5
~T~
2
2.5 3 3.5
darex (oz/yard)
-------
1E-06
<
E
CD
o
Q.
Q
1E-07
14
16 18
20 22 24 26 28 30 32
wrda79 (oz/yard)
-------
1E-07
tn
cv]
<
ZJ
_Q
Q
1E-08
0.11 0.12 0.13 0.14
0.15 0.16 0.17 0.18 0.19
porosity
-------
1E-07
c3
<
E
3
XI
Q
1E-08
0.
5
0.6
waterrcement
-------
1E-07
<
E,
3
XJ
Q
1E-08H 1 r-
200 220 240
260 280 300 320 340 360
cement (lbs/yard)
-------
1E-07
cS
<
E
13
_Q
Q
1E-08
100
120
140 160 180
flyash (lbs/yard)
200
220
-------
1E-07
CO
C\1
<
3
JD
Q
1 E"° 420 430 440 450 460 470 480 490
total cementitious materials (lbs/yard)
-------
1E-07
c5
<
E
13
XI
1E-08H—
1260
1280
I
1300 1320 1340 1360 1380
sand (lbs/yard)
-------
1E-07
<
JE
3
_Q
Q
::
1E-08
1600
1620
1640 1660 1680
stone (lbs/yard)
1700
1720
-------
1E-07
c3
<
E
3
XI
I
I
1E-08
250 255 260 265
270 275 280 285 290 295 300
water (lbs/yard)
-------
1E-07
c3
<
E
3
XI
~
1E-08H ' x
1 1.5 2
2.5 3 3.5
darex (oz/yard)
-------
1E-07
CO
C\J
<
E
ZJ
JO
a
1 E-08i . r-
14 16 18
¦
20 22 24 26 ~28 30 32
wrda79 (oz/yard)
-------
1E-06
CO
c\]
<
E
2>
o
Q-
Q
1E-07
0.11 0.12 0.13 0.14
015 016 017 018 0A9 0.2
porosity
-------
CO
C\J
<
E
1E-06
9>
o
Q.
Q
1E-07
0
0.6
water.cement
-------
1E-06
CO
o3
<
E
2>
o
Q.
Q
1E-07
200 220
240
260 280 300 320 340 360
flyash (lbs/yard)
-------
1E-06
c3
<
E
£
o
Q.
Q
1E-07H 1 r-
200 220 240
260 280 300 320 340 360
cement (lbs/yard)
-------
1E-06
<
E
2>
o
CL
Q
1E-07-
0
0.1 0.2 0.3 0.4 0.5
total cementitious materials (lbs/yard)
0.6
0.7
-------
1E-06
CO
CV)
<
E
8?
o
Q.
¦
1E-07
1260 1280
1300 1320 1340 1360 1380
sand (lbs/yard)
-------
r
1E-06
oo
<
E
8>
o
Q.
Q
::
1E-07
1600
1620
1640 1660 1680 1700 1720
stone (lbs/yard)
-------
1E-06
<
E
8>
o
Q.
Q
I
1E-07-J-
250
255 260 265
270 275 280 285 290 295 300
water (lbs/yard)
-------
1E-06
CO
C\]
<
E
£
o
Q.
1E-07
1
1.5
2.5 3 3.5
darex (oz/yard)
-------
V
1E-06
NO
o
<
E
S
o
Q.
Q
1E-07
14
16
18
20 22 24 26 28 30 32
wrda79 (oz/yard)
-------
1E-07
<
E,
*
3
JD
D
1 E-08H r—
0.11 0.12
013
014
015 016 017 018 019 0.2
porosity
-------
1E-07
^co
CM
<
E
3
JD
Q
1E-08
0.
5
0.6
water.cement
-------
1E-07
<
E,
*
JD
Q
1E-08
100
120
140 160 180
flyash (lbs/yard)
200
220
-------
1E-07
CO
<
~
Q
1E-08-I 1
200 220 240
I
260 280 300 320 340 360
cement (lbs/yard)
-------
1E-07
<
E,
*
XI
Q
1E-08-
420
430 440 450 460 470
total cementitious materials (lbs/yard)
480
490
-------
1E-07
=3
.Q
Q
1E-08-1 .
1260 1280
1300 1320 1340 1360 1380
sand (lbs/yard)
-------
r
1E-07
vo
-j
a)
<
*
_Q
Q
::
1E-08-I—
1600
1620
1640 1660 1680 1700
stone (lbs/yard)
1720
-------
1E-07
ca
<
*
13
JD
a
¦
¦
1E-08-
250 255 260 265
270 275 280 285 290 295 300
water (lbs/yard)
-------
1E-07
^3
cvi
<
*
13
_Q
Q
1E-084
1
•L5
2.5 3 3.5
darex (oz/yard)
-------
CM
<
E
U
JD
Q
20 22 24 26 28 30 32
wrda79 (oz/yard)
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing) |||
llllllllllllllllllllllllllll '
PB94-162 781
1 . REPORT NO. 2.
EPA-600/R-94-053
3. RECIPIEN III
4. TITLE AND SUBTITLE
Laboratory Assessment of the Permeability and Dif-
fusion Characteristics of Florida Concretes, Phase
I. Methods Development and Testing
5. REPORT DATE
April 1994
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S) " w
R. Snoddy
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
A cur ex Environmental Corporation
P.O. Box 13109
Research Triangle Park, North Carolina 27709
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-DO-0141, Task 91-012
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air and Energy Engineering Research Laboratory
Research Triangle Park, NC 27711
13. TYPE OF REPORT AND PERIOD COVERED
Task Final; 10/90 - 9/91
14. SPONSORING AGENCY CODE
EPA/600/13
is. supplementary notes ^^ERL project officer is David C. Sanchez, Mail Drop 54, 919/
541-2979.
16. abstract TJtie rep0rt; gives results of Phase I of a laboratory assessment of the per-
meability and diffusion characteristics of Florida concretes. (NOTE: The ability of
concrete to permit air flow under pressure (permeability) and the passage of radon
gas without any pressure difference (diffusivity) has not been well determined. To
establish a standard concrete mix and its maximum radon-resistant placement, these
parameters needed to be quantified and their relationship to concrete's physical pro-
perties evaluated.) The concrete testing consisted of separate permeability and dif-
fusivity measurements and a set of preliminary measurements to determine the size,
weight, and porosity of each sample. Ten concrete samples were tested. Cylinders
represented one of the four general types of concretes manufactured in Florida. Per-
meability was measured with a device developed for this project using custom soft-
ware. The diffusion coefficient was determined with a system developed by and pur-
chased from Rogers and Associates Engineering Corporation. Two of the samples
had measured permeabilities 100 times greater than the other samples due to defects
in the concrete. All of the correlations of the various physical parameters were in-
vestigated, but there was insufficient data to confidently determine any correlations.
The most significant fault was the lack of unbiased, representative concrete samples.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Pollution
Concretes
Permeability
Diffusion
Radon
Asseesments
Pollution Control
Stationary Sources
13 B
13 C
14 G
07B
14B
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
113
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
------- |