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Performance Evaluation of Lime Stabilized Performance Evaluation of Lime Stabilized Materials on...
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30/04/2013 1 Performance Evaluation of Lime Stabilized Performance Evaluation of Lime Stabilized Materials on Field Test Sites Materials on Field Test Sites 1 Tania Ávila-Esquivel Gustavo A. Badilla-Vargas June 2013 INTRODUCTION COSTA RICA, Central America
Transcript of Performance Evaluation of Lime Stabilized Performance Evaluation of Lime Stabilized Materials on...
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Performance Evaluation of Lime Stabilized Performance Evaluation of Lime Stabilized Materials on Field Test SitesMaterials on Field Test Sites
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Tania Ávila-EsquivelGustavo A. Badilla-Vargas
June 2013
INTRODUCTION
COSTA RICA, Central America
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INTRODUCTION
Some facts about COSTA RICA…
52 000 k 2 (T i 700 000 k 2 M i i 2 000 000 k 2)• 52,000 km2 (Texas is 700,000 km2, Mexico is 2,000,000 km2)• 4,509,290 inhabitants• No army since 1948• 2,5 millions of tourists in 2010• Language: Spanish• Currency: El Colón• Capital: San José• Two seasons: Rainy and Dry• 20 volcanos aprox. 5 active during last century
INTRODUCTIONElevations
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INTRODUCTION
• Due to the geological characteristics of Costa Rica, subgrade soils around the country often have high plasticity indexeshigh plasticity indexes.
These soils are
used as foundation for
pavement structures or
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unpaved roads.
Considerations for the selection of lime as a suitable means of soil stabilization:
• Gradation
INTRODUCTION
• Plasticity or soil texture
As a general rule lime reacts with soils of
medium to high plasticity.
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FIELD TEST SITEST1 Characteristics:
• Location: Barrio La Unión, Cañas, Guanacaste (Latitude N10°25.873’ Longitude W85°05.929’)
• Dry climatic region windy flat alignmentDry climatic region, windy, flat alignment• Soil type: SM (USCS) or A‐4 (AASHTO)• 6% Lime, after pH test• Low plasticity, lime added for dust control• 20cm thickness, 100m length
T2 Characteristics:• Location: Calle El Alto, Sector Copalchí, Distrito Quebradilla, Cartago
(Latitude N9°49.739’ Longitude W84°01.729’)• Humid climatic region, forest area, flat alignment• Soil type: ML (USCS) or A‐6(5) (AASHTO)• 6% Lime, after pH test• High plasticity, lime added to decrease deformation and improve
resistance• 20cm thickness, 100m length
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T1: FIELD TEST SITE
N
T2: FIELD TEST SITE
N
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Number of Rain Days per Year
CLIMATE CONDITION OF THE SITES
T1
T2
Number of Dry Months per Year
CLIMATE CONDITION OF THE SITES
T1
T2
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CAÑAS FIELD TEST SITECAÑAS FIELD TEST SITE
(T1)(T1)
FIELD CONDITION BY THE END OF 2011
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INITIAL SUBGRADE CONDITION
INITIAL SOIL SCARIFICATION
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SPREADING OF LIME
MIX AND HOMOGENIZATION PROCESS
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WATER DISTRIBUTION
RECONFORMATION OF THE SUBGRADE
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VISUAL ASSESMENT
Before After
MONITORING - 1 MONTH
Dry SeasonPresence of
surface crackssurface cracks
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MONITORING - 2 MONTHSDry SeasonPresence of
surface crackssurface cracks
MONITORING - 4 MONTHS
Rainy SeasonSurface damage
due to rainfall
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MONITORING - 7 MONTHS
Rainy SeasonSurface damage
due to rainfalldue to rainfall
MONITORING - 1 YEAR
Dry SeasonDry Season
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PERFORMANCE (LWD RESULTS), Example
60
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Elastic Modulus (0+040 m)Load II (7kN)
Load I (5kN)
Initial Condition
20
30
40
50
60
Modulus (M
Pa)
Dry Season
Rainy Season
0
10
Jan 10, 12 Jan 12, 12 March, 12 May 29, 12 May 30, 12 Aug, 12 Nov, 12 Jan, 13
PERFORMANCE (DCP RESULTS)
0 0
0 50 100 150
CBR (%)
CBR vs. Penetration (0+060 m)
0,0
200,0
400,0
600,0
800,0
enetration(m
m)
Jan 10, 2012
Jan 12, 2012
March 2012
May 2012
Sept 2012
1000,0
1200,0
1400,0
Pe
Jan 2013
JPAM5
Diapositiva 28
JPAM5 Conversemos sobre este gráfico mañanaJosé Pablo Aguiar Moya, 29/04/2013
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CARTAGO FIELD TEST SITECARTAGO FIELD TEST SITE
(T2)(T2)
Effects produced byaccumulation of waterdue to lack adequate
FIELD CONDITION BY THE END OF 2011
qsurface drainage system
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INITIAL SUBGRADE CONDITION
INITIAL SOIL SCARIFICATION
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SPREADING OF LIME
MIX AND HOMOGENIZATION PROCESS
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WATER DISTRIBUTION
RECONFORMATION OF THE SUBGRADE
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VISUAL ASSESMENT
Before After
MONITORING - 1 MONTH
Dry Season
Section of the roadnot stabilized
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MONITORING - 2 MONTHS
Dry SeasonPresence of
surface crackssurface cracks
MONITORING - 4 MONTHSRainy SeasonEffects produced byaccumulation of waterdue to lack adequatedue to lack adequatesurface drainage system
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Section of the roadnot stabilized
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MONITORING - 7 MONTHS
Eff t d d
Section of theroad notstabilized
Effects producedby accumulationof water due tolack adequatesurface drainagesystem
MONITORING - 1 YEAR
Dry Season
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Section of the roadnot stabilized
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PERFORMANCE (LWD RESULTS), Example
Initial Condition60
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Elastic Modulus (0+020 m) Load II (7kN)
Load I (5kN)
Dry Season
Rainy Season
30
40
50
60
Modulus (M
Pa)
0
10
20
Feb 14, 12 Feb 15, 12 March, 12 Apr, 12 June, 12 Sept, 12 Nov, 12 March, 13
M
PERFORMANCE (DCP RESULTS), Example
0
0 20 40 60 80 100 120
CBR (%)
CBR vrs penetration (0+060 m)
0
200
400
600
800Penetration (mm) Feb 14, 2012
Feb 15, 2012
March 2012
April 2012
Sept 2012
1000
1200
1400
Sept 2012
Nov 2012
Feb 2013
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ADVANTAGES OF APPLYING LIME
Technical Advantages:
• Allows the use of natural soil, improving the mechanical propertiesproperties.
• Ensures the stability of the road surface, due to its reduction in permeability
• Reduces volume changes due to swelling or shrinkage,
• Higher resistance to erosion.
• Maintain subgrade elevation, especially if there are l k l d i lcomplementary works already in place.
• Allows immediate opening to traffic.
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Economic and environmental benefits:
ADVANTAGES OF APPLYING LIME
• Increased use of local materials, sometimes with inadequate characteristics. Minimize the need of long hauling distances.
• Improved efficiency in construction process when high performance equipment is used.
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FINAL COMMENTS
• Compaction process is crucial in ensuring the benefits of lime stabilization.
• Improvements have been indentified on lime stabilized• Improvements have been indentified on lime stabilized materials.
– However, longer monitoring will be conducted to measuremid‐ and long‐ term performance.
• Observed material response variations can be associated to Seasonal Variation (dry‐rainy season).
THANK YOU FOR THE ATTENTION!
t i il i [email protected]@[email protected]
