Suelo natural modificado con polímero para su uso en sistemas de

rellenos sanitarios L. Marti, I. Cueto, S. Rearte, S. Pastine, M. T. Fernández, M. Mansilla,

M. Codevilla, A. Vazquez, T. M. Pique, D. Manzanal

Laboratorio de Mecánica de Suelos y Geología - INTECIN - UBA - CONICET

Instituto de Tecnología en Polímeros y Nanotecnología - UBA – CONICET

Grupo de investigación en geomecánica

•  Grupo LMS-INTECIN tiene doble dependencia UBA-CONICET –  UBA:

•  Dr. Ing. Alejo Sfriso •  Ing. Mauro Codevilla •  Ing. Osvaldo Ledesma

–  CONICET: •  Dr. Ing. Manzanal

2

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

Índice

•  Introducción

•  ¿Qué es un polímero?

•  ¿Qué es un suelo - polímero?

•  Programa experimental

•  Primeras conclusiones

•  Próximos trabajos

3

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

Introducción

•  El suelo se modifica para cambiar su condición natural, para mejorar, por ejemplo, las características resistentes o sus propiedades hidráulicas.

•  Los materiales clásicos para mejorarlo son conglomerantes hidráulicos: cemento, cal y productos similares.

•  En este trabajo se busca mejorar el suelo con la aplicación de una baja proporción de polímero.

4

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

¿ Qué es un polímero ?

•  Son macromoléculas compuestas por una o varias unidades químicas (monómeros) que se repiten a lo largo de una cadena.

•  Hoy en día se utilizan en todas las industrias, sobre todo en la construcción.

5

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

procedures in the American Petroleum Institute (2003) and

Federation of Piling Specialists (2006a) for bentonite, except

that bleach was used to break the polymer prior to the sand

content test. It should be noted that the sand content test was

developed in the USA and the screen size is 75 !m. Thus the

sand content test determines the quantity of material coarser

than 75 !m (by bulk volume).

Before each test, the fluid sample was stirred vigorously to ensure

uniform dispersion of all the soil particles – a step which is

especially important for the density and sand content tests. No

screening was carried out to remove the coarse particles except

for the Marsh funnel test where the fluid was poured through the

No. 12 mesh (1.6 mm opening) built into the top of the funnel –

this is to prevent the gravel-sized particles from blocking the

orifice which has an inside diameter of 4.7 mm (3/16 in). At this

site, although the alluvial silty sand does not contain any gravel-

sized particles (Figure 2), the thin coal (lignite) layer above the

bedrock was broken into small pieces of sand- and gravel-sized

fragments by the excavation tools and some of them were found

in suspension in the support fluids; hence the need for pre-

screening before the Marsh funnel tests.

Figure 4 shows the density, sand content and Marsh funnel test

results plotted against depth for one of the working piles for three

stages: (a) immediately after excavation, (b) after fluid cleaning

with the chemical additive ‘MPA’ and 30 min of waiting, and (c)

as (b) but plus an overnight waiting period. The additive ‘MPA’ is

Figure 3. A twin-flight piling auger immediately after retrieval

from a polymer-supported bore. Note the second flight is for fluid

passage

20

18

16

14

12

10

8

6

4

2

01·00 1·02 1·04 1·06 1·08

Density: g/cm3

Dep

th: m

20

18

16

14

12

10

8

6

4

2

00 1 2 3 4 5 6

Sand content: %

Dep

th: m

20

18

16

14

12

10

8

6

4

2

040 50 60 70 80

Marsh funnel viscosity: s

Dep

th: m

Increasing time Increasing time Increasing time

Affected by orificepartial blockage

After an additional overnightwaiting period

After fluid cleaning with additiveMPA and 30 min waiting

Immediately after excavation

Figure 4. Density, sand content and Marsh funnel viscosity

profiles in a completed pile bore

4

Geotechnical Engineering Construction techniques for bored pilingin sand using polymer fluidsLam, Jefferis and Suckling

¿ Qué es un suelo - polímero ?

•  Es un nuevo material que junto con el aporte del agua reacciona químicamente.

•  El polímero en bajas dosis modifica las propiedades físicas, mecánicas e hidráulicas del suelo.

6

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

Programa experimental

•  Caracterización física y química del polímero •  Caracterización física del suelo utilizado •  Selección % polímero incorporado •  Estudio de mezclas (arena-suelo-polímero)

–  Caracterización física (MIP) –  Caracterización hidráulica (SWCC) –  Caracterización hidromecánica (free swell–swell pres.) –  Caracterización mecánica mezcla (UCS)

7

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

Caracterización física suelo

•  Suelo: arcilla de alta plasticidad procedente de Comodoro Rivadavia, Chubut

•  Inerte: arena comercial de origen fluvial

8

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

weight and high charge density of the anionic polyacrylamide have shown to improve physical, hydraulic and mechanical properties of different soils [6].

In this paper, the influence of the addition of anionic polyacrylamide to different soils mixtures is studied as part of a research project developing at Buenos Aires University. A clay-polymer and sand-clay-polymer mixture with a 1.5 % polyacrylamide by weight has been studied. The results are presented in terms of the variation of the index properties, the effects of polymeric additives in the potential expansion of the samples, the relationship of suction-degree of saturation and unconfined compression strength.

2. Materials

2.1. Soils

The soils used in the tests consisted of a granular material and fine soil which were mixed in suitable proportions. The granular material is commercial river sand. The index properties of the sand are shown in Table 1. Table 1. Physical properties of the commercial river sand soil.

USCS #200 (%)

Cu Cc D50 (mm)

Gs φc (º)

SP 5 2.5 1.3 0.38 2.67 30.5

The fine material is a high plasticity clay from Comodoro Rivadavia city, Chubut, Argentina. The soil exhibits plastic behaviour over a wide range of moisture contents and has high liquid limits. Based on the physical soil characteristics presented in Table 2, this soil is classified as MH as per Unified Soil Classification System (USCS). However, 80 % of the minerals obtained by DRX test are montmorillonite. The maximum adsorption of the methylene blue corresponds to the specific surface of the clay particles [7]. The specific surface of this clay is an expected value for montmorillonite mineral [8]. Table 2. Physical properties of the clay soil.

USCS #200 (%)

LL (%)

PL (%)

SL (%)

Clay (%)

γdmáx

(kN/m3) ω ópt (%)

Ss (m2/gr)

ksat (m/seg)

MH 96 80 39 17.5 90 13.0 31.0 337 1.5 10-10

2.2. Polymer

The additive used is a hydrophilic synthetic polymer called FAISAN AP-1011 anionic polyacrylamide (APAM). This polyacrylamide has very high molecular weight (10-20 mg mol-1) and high anionic charge density. Polyacrylamide at room temperature is presented as a white crystalline solid. It is water soluble, highly viscous and environmentally safe, able to stabilize different soil types [5, 6 ,9]. Figure 1 shows the molecular structure of the anionic polyacrylamide used and the powder state at room temperature.

Propiedades físicas de la arcilla.

weight and high charge density of the anionic polyacrylamide have shown to improve physical, hydraulic and mechanical properties of different soils [6].

In this paper, the influence of the addition of anionic polyacrylamide to different soils mixtures is studied as part of a research project developing at Buenos Aires University. A clay-polymer and sand-clay-polymer mixture with a 1.5 % polyacrylamide by weight has been studied. The results are presented in terms of the variation of the index properties, the effects of polymeric additives in the potential expansion of the samples, the relationship of suction-degree of saturation and unconfined compression strength.

2. Materials

2.1. Soils

The soils used in the tests consisted of a granular material and fine soil which were mixed in suitable proportions. The granular material is commercial river sand. The index properties of the sand are shown in Table 1. Table 1. Physical properties of the commercial river sand soil.

USCS #200 (%)

Cu Cc D50 (mm)

Gs φc (º)

SP 5 2.5 1.3 0.38 2.67 30.5

The fine material is a high plasticity clay from Comodoro Rivadavia city, Chubut, Argentina. The soil exhibits plastic behaviour over a wide range of moisture contents and has high liquid limits. Based on the physical soil characteristics presented in Table 2, this soil is classified as MH as per Unified Soil Classification System (USCS). However, 80 % of the minerals obtained by DRX test are montmorillonite. The maximum adsorption of the methylene blue corresponds to the specific surface of the clay particles [7]. The specific surface of this clay is an expected value for montmorillonite mineral [8]. Table 2. Physical properties of the clay soil.

USCS #200 (%)

LL (%)

PL (%)

SL (%)

Clay (%)

γdmáx

(kN/m3) ω ópt (%)

Ss (m2/gr)

ksat (m/seg)

MH 96 80 39 17.5 90 13.0 31.0 337 1.5 10-10

2.2. Polymer

The additive used is a hydrophilic synthetic polymer called FAISAN AP-1011 anionic polyacrylamide (APAM). This polyacrylamide has very high molecular weight (10-20 mg mol-1) and high anionic charge density. Polyacrylamide at room temperature is presented as a white crystalline solid. It is water soluble, highly viscous and environmentally safe, able to stabilize different soil types [5, 6 ,9]. Figure 1 shows the molecular structure of the anionic polyacrylamide used and the powder state at room temperature.

Propiedades físicas de la arena

DRX y SEM de la arcilla

Caracterización física polímero

•  Polímero: Poliacrilamida Aniónica (APAM) •  no tóxico, soluble en agua. •  alto peso molecular •  alta carga catiónica •  Tg > 50ºC.

9

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

0,1 1 10 100 10000

10

20

30

40

50

60

70

a)

!

!

APAM

Time [log(h)]

Abs

orpt

ion

[%]

Capacidad de absorción de la APAM

!Monómero de la APAM

Selección % polímero incorporado

•  Se trabajó con distintos porcentajes de APAM en peso de arcilla y se eligió un 1.50 % APAM

10

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

moisture content: the optimum, the dry of optimum and the wet of optimum. Before changing the moisture content of the mixtures of clay-polymer and sand-clay-polymer, materials were premixed in dry state. Previously the clay was sieved through the # Nº 10 ASTM series.

3.2. Clay–Polymer and Sand–Clay–Polymer mixtures

The anionic polyacrilamine (APAM) is used to modify the studied mixtures. The nature of clay-polymer and sand-clay-polymer interactions is of interest because it affects the engineering properties of the soil. The addition of 0.5 and 1.5 % of polymer by weight to the mixture has been studied. The index properties for clay-polymer mixture are presented in Table 3. Table 3. Physical properties of the clay–polymer mixture.

% polymer USCS LL (%)

PL (%)

SL (%)

γdmáx

(kN/m3) ω ópt (%)

0.5 % of APAM CH 150 50 16.3 13.10 28.1 1.5 % of APAM CH 170 60 15.7 12.36 23.1

Based on index properties given in Table 3, it appears that the clay-polymer

mixture increases its plasticity index from 41 % to 100 %. The mixture has wide range of moisture contents related with a plastic behaviour. An increase in weight percent of these polymers lead to an increase in the liquid limit. The water absorption capacity of the polymer (60 % absorption) confirms the results obtained. Incremented consistency limits indicate that more water should be incorporated into the mixture to reach a similar consistency to clay. Addition of water to the mixture creates a continuous network of transparent wires throughout the mixture due to the hydration of the polymer.

The standard Proctor compaction test of the mixture showed a reduction of 5 % in the value of maximum dry density and decreased of the optimum moisture content from 31.0 % to 23.1 %. The maximum adsorption of the methylene blue and the Particle Size Analysis by Hydrometer Method could not be determined.

A small amount of polymer addition modified the index properties of the clay. The percentage of polymer added by clay weight was set at 1.5 %.

Specimens of sand-clay-polymer compacted at maximum dry density by standard Proctor method. The suitable percentage by weight of clay-polymer which gave the maximum dry density of the mixture (sand-clay-polymer) was obtained from a series of standard Proctor tests varying clay-polymer content. Figure 4a shows that as clay-polymer content increases, the maximum dry density of the mixture increases to its maximum value at 15 % of clay-polymer. This value then decreases approaching to the maximum dry density of the clay-polymer. The mixture adopted is 85 % sand and 15 % clay-polymer, of which 1.5 % is anionic polyacrylamide (APAM).

A schematic representation of the interaction between soil and polymer is presented in Figure 5. First, the three materials are dissociated. Then, moisture content of the mixture change, the polymer starts to absorb water, expand and interact, first with the fine soil matrix and then with the granular soil, reducing the porosity of the skeleton.

Mezcla + 0.50% APAM.

Propiedades físicas de la mezcla arcilla-polímero.

SEM y MIP de la mezcla arcilla-0.50% APAM.

Estudio de mezclas

•  Fracción fina: arcilla + 1.50% APAM •  Fracción gruesa: arena comercial (inerte) •  Compactación dinámica (Proctor Standard) •  Objetivo: nuevo material (arena+arcilla+APAM)

para uso en rellenos sanitarios

11

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

MEZCLA ÓPTIMA: 85% ARENA + 15% (ARCILLA-1.50% APAM). !

Estudio de mezclas

•  MIP: reducción de poros en el rango 0.01 - 0.06 µm (micro) y 0.30 - 10 µm (macro). A confirmar ! (primeros resultados)

12

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

Figure 4. a) Standard Proctor compaction for sand, clay and different sand-clay-polymer mixtures.

b) Evolution of maximum dry density of the sand-clay-polymer mixture for different clay-polymer additions.

Figure 5. Schematic representation of the interaction between soil and polymer.

Figure 6 shows the evolution of the results of mercury intrusion porosimetry data for compacted samples wet of optimum water content of sand-clay mixture with and without polymer. The addition of polymer appears to reduce pores in the range of 0.01 µm - 0.06 µm and 0.3 µm - 1 µm. This analysis requires further research to confirm the analysis.

0

2

4

6

8

10

12

14

16

1 10 100 1000 10000

Pore+size+den

sity+functio

n,+dV/dlog(D)+

[mm3/g]

Entrance+pore+size,+D+[nm]

SandFClayFPolymer

SandFClay

Figure 6. Pore size distribution curve on sand-clay and sand-clay-polymer mixture.

3.3. Suction measurements on soil-polymer mixtures

The matric suction of the unsaturated clay-polymer and sand-clay-polymer mixture samples, compacted at 95 % of the maximum dry density, was carried out by the contact filter paper method. The filter paper method consists in measuring the moisture content of the calibrated filter papers in contact with soils (matric suction) or in equilibrium with the partial vapor pressure in a sealed container (total suction) [10]. The calibration between the gravimetric water contents of the filter paper and suction used in this study were that proposed by ASTM D 5298 [11]. All samples required 15 days to reach equilibrium between the Whatman 42 filter paper and the soil-polymer

MIP curve on 85% sand-15% clay-APAM and 85% sand – 15% clay mixtures.

Estudio de mezclas

•  SWCC: vGF arcilla-polímero y arena-arcilla-polímero se ubican entre vGF arcilla y arena-arcilla.

•  sae se incrementa con la incorporación de APAM

13

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

!

mixtures. This technique requires that the temperature fluctuations are no larger than 1 °C. Knowing the calibration curve and gravimetric water content of Whatman 42 filter paper after equilibrium, matric and total suction values were obtained. The matric suction values obtained are plotted versus saturation degree in Figure 7 for natural clay, the sand-clay mixture, the clay-polymer mixture and the sand-clay-polymer mixture.

The experimental results of the soil-polymer mixture were fitted with the van Genuchten function (vGF) [12]:

11

1eae

sSs

λ

λ

−

−# $

# $% &= + % &% &' (% &' (

(1)

where sae is air entry value, Se is effective saturation degree and λ is a parameter of pore distribution. The calibrated parameters are shown in Table 4. The matric suction versus effective saturation degree for different soils mixture is shown in Figure 7. It can be seen that the vGF of clay-polymer and sand-clay-polymer mixtures are located between the vGF of clay and sand-clay mixture. The vGF slopes tend to increase for sand mixture, suggesting an increase in the rate of the saturation degree changes with respect to matric suction changes. Table 4. Parameters for van Genuchten model for soil-polymer mixtures

Sample γd

(kN/m3) λ (-)

sae (kPa)

Clay 12.4 0.16 200 Clay-Polymer 0.5% 12.5 0.13 35 Sand-Clay Mixture 17.2 0.50 2

Sand-Clay-Polymer 1.5% 17.2 0.70 6

Figure 7. Suction measurements and Van Genuchten model for clay, clay-polymer and sand-clay-polymer.

The air-entry value of the mixture with polymer is higher than sand-clay mixture. However, the polymer amended clay show lower values than the natural clay. The polymer-clay interaction alters the clay particle surface properties [9] and influences the clay and clay-sand arrangement. The particle association type and number of associations that develop depends on the solids content of the system [13], this aspect

Parameters for van Genuchten model for sand-clay-polymer mixtures.

Suction measurements and vGF curves for sand-clay-polymer mixtures.

Se = 1+ssae

!

"##

$

%&&

11−λ

!

"

###

$

%

&&&

−λ

Estudio de mezclas

•  Muestras compactas al 95% PS •  Free swell & swelling pressure: fuerte incremento

por adición de APAM (>100%), controlado en muestras con arena

14

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

could be a possible explanation. Further research is being undertaken to study the arrangement of the polymer-soils mixtures with scanning electron microscopy.

3.4. Free swell and swelling pressure

The swelling properties (ASTM D 4546) were measured in mixtures of clay-polymer and sand-clay-polymer for compacted samples to 95 % of maximum dry densities of Proctor method. In the swelling pressure test the specimen is flooded and free swell is determined under a load of 2 kPa until equilibrium. Then the load is increased until the initial void ratio to determine the swelling pressure. On Table 5 the results of the tests of free-swelling and swelling pressure are shown. Table 5. Free-swelling and swelling pressure experimental results for clay, clay-polymer, sand-clay-polymer and sand-clay-polymer mixtures.

Sample γd (kN/m3)

Sr 0

(%) e0 ef ΔH/H0

(%) σsp

(kPa) Cc Cs

Clay 12.99 62.11 1.00 1.43 21.30 700 0.33 0.08 Clay-polymer 1.5 % 13.05 76.14 1.01 2.00 49.34 1300 0.40 0.07

Sand-Clay 15 % 17.17 57.70 0.50 0.54 2.68 - 0.01 0.01 Sand- (Clay-Polymer 1.5 %) 15 % 17.07 60.42 0.51 0.61 6.35 450 0.05 0.01

The polymer addition caused a high free swell due to the high water absorption of the polymer. The sand-clay mixtures experience less swelling potential, being higher in the sample with polymer addition. Swelling pressure in the natural clay samples is about 700-800 kPa and clay-polymer samples this value increased to 1300 kPa. The sand-clay-polymer mixture has a swelling pressure 450 kPa. These results could be associated with lower hydraulic conductivities that it should be confirmed with permeability tests.

3.5. Unconfined compression test (UCS)

Unconfined compressive tests to evaluate the effect of the polymer in the strength of the material were made. Dynamically compacted samples of sand-clay and sand-clay-polymer mixtures were prepared. Three samples for each mixture with moisture content at optimum, dry of optimum and wt of optimum were tested under deformation rate of 1 mm / min. The results are shown in Table 8. As it is expected the addition of polymer alters in mechanical properties increasing the compressive strength. Table 8. Results of unconfined compressive tests

Mixture Dry site Optimum Wet site

Sand 85 % - Clay 15 %

γd = 16.6 kN/m3 γd = 17.2 kN/m3 γd =17.05 kN/m3 ω = 9.0 % ω = 12.8 % ω =13.5 %

qu = 13.5 kPa qu = 27.9 kPa qu =17.7 kPa

Sand 85 % - (Clay–APAM) 15 %

γd = 16.9 kN/m3 γd = 17.1 kN/m3 γd =16.9 kN/m3 ω = 10.0 % ω = 12.0 % ω = 15.0 %

qu = 14.6 kPa qu = 32.5 kPa qu = 24.7 kPa

Free-swelling and swelling pressure experimental results for clay, clay-polymer, sand-clay-polymer and sand-clay-polymer mixtures.

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0

1 10 100 1,000 10,000 100,000 1,000,000 10,000,000

ΔH (mm)

log$t$(seg)

0.80

1.30

1.80

2.30

1 10 100 1000 10000

e

log σ´$(kPa)$

Estudio de mezclas

•  Muestras compactas al 95% PS •  UCS: aumento resistencia por adición de APAM

15

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

UCS experimental results for sand-clay-polymer and sand-clay-polymer mixtures.

could be a possible explanation. Further research is being undertaken to study the arrangement of the polymer-soils mixtures with scanning electron microscopy.

3.4. Free swell and swelling pressure

The swelling properties (ASTM D 4546) were measured in mixtures of clay-polymer and sand-clay-polymer for compacted samples to 95 % of maximum dry densities of Proctor method. In the swelling pressure test the specimen is flooded and free swell is determined under a load of 2 kPa until equilibrium. Then the load is increased until the initial void ratio to determine the swelling pressure. On Table 5 the results of the tests of free-swelling and swelling pressure are shown. Table 5. Free-swelling and swelling pressure experimental results for clay, clay-polymer, sand-clay-polymer and sand-clay-polymer mixtures.

Sample γd (kN/m3)

Sr 0

(%) e0 ef ΔH/H0

(%) σsp

(kPa) Cc Cs

Clay 12.99 62.11 1.00 1.43 21.30 700 0.33 0.08 Clay-polymer 1.5 % 13.05 76.14 1.01 2.00 49.34 1300 0.40 0.07

Sand-Clay 15 % 17.17 57.70 0.50 0.54 2.68 - 0.01 0.01 Sand- (Clay-Polymer 1.5 %) 15 % 17.07 60.42 0.51 0.61 6.35 450 0.05 0.01

The polymer addition caused a high free swell due to the high water absorption of the polymer. The sand-clay mixtures experience less swelling potential, being higher in the sample with polymer addition. Swelling pressure in the natural clay samples is about 700-800 kPa and clay-polymer samples this value increased to 1300 kPa. The sand-clay-polymer mixture has a swelling pressure 450 kPa. These results could be associated with lower hydraulic conductivities that it should be confirmed with permeability tests.

3.5. Unconfined compression test (UCS)

Unconfined compressive tests to evaluate the effect of the polymer in the strength of the material were made. Dynamically compacted samples of sand-clay and sand-clay-polymer mixtures were prepared. Three samples for each mixture with moisture content at optimum, dry of optimum and wt of optimum were tested under deformation rate of 1 mm / min. The results are shown in Table 8. As it is expected the addition of polymer alters in mechanical properties increasing the compressive strength. Table 8. Results of unconfined compressive tests

Mixture Dry site Optimum Wet site

Sand 85 % - Clay 15 %

γd = 16.6 kN/m3 γd = 17.2 kN/m3 γd =17.05 kN/m3 ω = 9.0 % ω = 12.8 % ω =13.5 %

qu = 13.5 kPa qu = 27.9 kPa qu =17.7 kPa

Sand 85 % - (Clay–APAM) 15 %

γd = 16.9 kN/m3 γd = 17.1 kN/m3 γd =16.9 kN/m3 ω = 10.0 % ω = 12.0 % ω = 15.0 %

qu = 14.6 kPa qu = 32.5 kPa qu = 24.7 kPa

0.0#

5.0#

10.0#

15.0#

20.0#

25.0#

30.0#

35.0#

0.0%# 5.0%# 10.0%# 15.0%# 20.0%# 25.0%# 30.0%# 35.0%# 40.0%#

q u (k

Pa)!

ε (%)!

DRY#

OPTIMUM#

WET#0"

5"

10"

15"

20"

25"

30"

0.0%" 5.0%" 10.0%" 15.0%" 20.0%" 25.0%" 30.0%"

q u (k

Pa)!

ε (%)!

DRY"

OPTIMUM"

WET"

Primeras conclusiones

•  APAM en contacto con agua forma un gel superabsorbente que interactúa con la fracción fina (arcilla) y granular (arena), generando agregación de partículas.

•  Se observó una reducción de la microporosidad en las muestras suelo – APAM.

•  Se observó un incremento en la capacidad de retención de agua por incorporación de APAM.

16

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

Próximos trabajos

•  Ensayo en columna de infiltración (permeabilidad no saturada)

•  Ensayos triaxiales con control de succión (próximo equipamiento LMS)

•  Estudio de nuevos polímeros (actualmente en ejecución – grupo LMS – tesis M. Fernández)

•  Modelado constitutivo y numérico a nivel de punto de gauss y problemas de contorno.

•  Estudio de numérico de estabilidad de un relleno sanitario con sistema polímero-arcilla-arena en la cobertura.

17

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

Publicación •  L. Marti, M. Codevilla, T. Piqué, D. Manzanal.

(2015). Natural Soil Modified with Polymer for use in landfill systems. Advances in Soil Mechanics and Geotechnical Engineering: Proceedings of the 15th Pan-American Conference on Soil Mechanics and Geotechnical Engineering (15th PCSMGE). 15 -17 November, Buenos Aires, Argentine. Ed. IOS Press.

18

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

Agredecimientos

•  A Dra. Ing. Analia Vázquez: la motivadora para avanzar en este tema conjunto entre dos grupos del ITPN y INTECIN. Y por la financiación aportada por el ITPN para el desarrollo de esta línea de investigación sobre mezclas suelo-polimero.

•  A Dr. Ing. Alejo Sfriso: motivador permanente de proyectos de investigación

•  Alumnos que participaron (y participan) de los trabajos en el LMS

19

Sue

los

natu

rale

s m

odifi

cado

s co

n po

límer

os

Gracias !!