Red Hawk-LR120110 Geotechnical 2209 Wisconsin St. Tel: 972.620.8911
ALPHA T E S T I N G Construction Materials Suite 100 Fax: 972.620.1302
Environmental Dallas, Texas 75229 www.alphatesting.com
TBPE Firm No. 813
WHERE IT ALL BEGINS
January 10, 2012
Creststone Group
225 E. Hwy 121, #120
Coppell, TX 75019
Attention: David Hayes
Re: Pavement Subgrade Stabilization
Red Hawk Residential
Coppell, Texas
ALPHA Report No. 110991 -41
Submitted herein are results of our analysis of the exposed pavement subgrade at the above referenced site. The
exposed pavement subgrade was evaluated by obtaining a total of eleven discrete samples from random locations
along the alignment of the roadway. Atterberg -limit tests were performed on two of the discrete samples. Lime
series tests by Atterberg- limits (ASTM C -977, Appendix XI) were performed on the more plastic soil material.
Results of the Atterberg -limit tests and the lime series are attached to this report.
Based on visual observation of the exposed pavement subgrade, results of the above described lime series and the
City of Coppell minimum hydrated lime required for subgrade stabilization, it is recommended the exposed
subgrade along all streets be mechanically lime stabilized with a minimum six percent hydrated lime by compacted
dry soil weight (e.g., 27 lbs of h drated lime per square yard for a 6 -inch thick compacted thickness). The rate of
hydrated lime applicati. isar is based on an assumed compacted dry soil unit weight of 100 pcf (by ASTM-
D698) which is considered typical for such calculations in the absence of actual standard Proctor compaction test
rte' results, but should be adjusted as necessary based on actual Proctor tests on the lime treated soil.
4 4
Mechanical lime stabilization should be performed in compliance with the Project Specifications. We appreciate the
opportunity to be of service on this project. If we can be of further assistance, please call upon us.
Thank you for this opportunity to provide our services. If we can be of further assistance, please contact us.
Sincerely,
ALPHA TESTING, INC.
Yonas Tanga.
CMT Project Manager
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Dallas • Ft. AForth • San Antonio
ATTERBERG- LIMITS LIME SERIES
25
20
X
0 15
co U �\
F- `\
10
5
0 - -
0% 1% 2% 3% 4% 5% 6% 7% 8% 9% 10%
PERCENT HYDRATED LIME
SAMPLE NO.: 1
DESCRIPTION: LIGHT BROWN SANDY CLAY
LOCATION: OXFORD PLACE AT STATION 3 +00
CLIENT: LABORATORY TEST:
Creststone Group LIME SERIES DATA
Coppell, TX FIGURE - 1
TBPE Firm No. 813
PROJECT NAME: ALPHA PROJECT NO.: DATE: 01/09/12
Red Hawk Residential 110991
Coppell, Texas
RESULTS OF LABORATORY TESTS
SAMPLE NO. LIQUID LIMIT PLASTICITY INDEX
1 33 19
8 32 17
LOCATION AND DESCRIPTION:
1 OXFORD PLACE AT STATION 3 +00
(LIGHT BROWN SANDY CLA
8 ALLEY AT STATION 4 +00
(DARK REDISH BROWN CLAY)
CLIENT: LABORATORY TEST:
Creststone Group ATTERBERG- LIMITS
Coppell, TX FIGURE — 2
TBPE Firm No. 813
PROJECT NAME: ALPHA PROJECT NO.: DATE: 01/09/12
Red Hawk Residential 110991
Coppell, Texas