______________ *Corresponding author. Tel: 609-5493374; Fax: 609-5492998 *Email address: anamdar@ump.edu.my

Improving Peat Engineering Properties by Natural Mineral Mixture

Nurmunira Muhammad, Abdoullah Namdar*, Ideris Bin Zakaria Faculty of Civil Engineering & Earth Resources, Universiti Malaysia Pahang, Malaysia ________________________________________________________________________________

____________________________ ___________________________________________________________________________ ______________________ ___________________________________________________________________

1. Introduction Any soil has specific engineering and mechanical properties. Among them the peat is one of weakest soil for construction or if located in subsoil shown high settlement, low bearing capacity and low shear strength. It is due to peat texture, mineralogy and morphology. The 8% of Malaysia covert by peat which is one of geotechnical problem faced this territory (Mutalib et. al., 1991). Moreover, Toh et al. (1994) also mention the peat has high water content in range of 200-2000%, low bulk densities of 10kN/m3 and low shear strength of the of 5-10 kPa, this is weak soil and requires a special treatment for improvement its characteristics.

The peat with a CBR of 2 to 4% in road construction

industry is resulted in weak serviceability, and unacceptable limit field deflection (MacFarlane, 1969), and consequently settlement and stress in subsoil is increased (Davitt and Killeen, 1996). Excavation to more stable materials such as rock, gravel or clay are recommended (Anon, 1978), and it is only economical method if road is constructed on peaty subsoil (Hampson, 1993), but sometimes due to site geomorphology excavation is not suitable method, and after excavation is required to replace suitable material with economical point of view.

The peat soil has very high compressibility compared to clay, sand and gravel (Charman, 2002). There are various types of natural and synthetics minerals have been used in construction industries, and from other hand many researcher are interest to develop new minerals for improving soil engineering properties. Instead, some cases of mineral usage have been discussed by other researcher. The presence of kaolin as a natural mineral additive also been widely used as ground improvement technique like dry deep mixing method using lime-cement columns that transferring physical load between column and subsoils, but Larson et.al. (2009) using kaolin for attract Na+ and K+ ions in lime to improve the undrained shear strength properties. There are also comparisons between the sodium silicate, OPC and kaolinite as binder in soil grouting columns for peat soil and it indicate that OPC result is much better than sodium silicate and kaolinite in terms of shear strength but kaolinite could form a connection with peat (Huat et al. 2011). Recently, the research findings will deeply discussed into the mineralogy and morphology of soils that could explain the existence of new minerals as stabilizer or binder (Hashim, 2003). The presence of kaolin as soil stabilizer by natural mixed with peat soil is not broadly discussed in geotechnical engineering especially for ground improvement. Seldom studies are documented for improve peat soil mechanical properties.

Keywords: Kaolin Heat Dry density Liquid limit Plastic limit

International Journal of Civil Engineering and

Geo-Environmental

Journal homepage:http://ijceg.ump.edu.my ISSN:21802742

A B S T R A C T A R T I C L E I N F O

The mixed soil is appropriate technique for solve geotechnical engineering problems. The main problem of case study is spreading peat in vast area. The exaction and replacing soil from far distance resulted in finishing project with high cost. In this regard improving peat mechanical properties by using modified kaolin under, 200°C, 400°C, 600°C and 800°C heat has been investigated. The liquid limit, plastic limit and dry density are main objectives in this research work. The result indicated that the new minerals are developed during modifying kaolin submitted to heat and it is improving peat liquid limit and plastic limit. And in soil mixture dry density is reduced, it is expected to improve peaty subsoil allowable deformation by using this technique in site. Thus further investigations are needed for assessing specimen shear strength, bearing capacity, settlement and deformation.

International Journal of Civil Engineering & Geo-Environmental 3 (2012) ______________________________________________________________________________________________________

24

1E-4 1E-3 0.01 0.1 10

20

40

60

80

100

Cum

ula

tive p

erc

enta

ge (

%)

Particle size (mm)

This is an investigation for improving some mechanical properties of peat by using natural mineral as additive. 2. Methodology The peat soil has been collected from Jalan Kuantan-Pekan, Pahang with a coordinate of longitude 103.301239E and latitude 3.650854N. The area was well-known with the problematic soil. The peat in that area was formed by decaying of vegetation in clayey or sandy soils. The sample was collected in mentioned area and has been mixed with unheated Kaolin and, heated Kaolin which was subjected to 200°C, 400°C, 600°C and 800°C heat. The mixture proportion of peat with each of unheated and heated Kaolin were 90:10, 80:20, 70:30, 60:40 and 50:50. The liquid limit, plastic limit, sieve analysis and standard proctor tests have been performed.

The liquid limit, plastic limit, sieve analysis and standard proctor tests have been performed. All tests were carrying out using BS 1377. Mineralogical analyses only been performed for percentage mixture of peat with the raw and thermally heated kaolin samples that attain maximum result for liquid limit and plastic limit by using X-ray diffraction instrument in UMP FIST laboratory. This is due to obtain the behavior of mixed samples when it under wet conditions. 3. Result and discussion

The mixed soil technique had been studied by several researchers. The soil mechanical properties and particle size distribution of peat soil are showed in Table 1 and Figure 1, respectively. The peat has low plasticity. The Figure 1 is indicated that the soil is well-graded and sand is a major proportion. Table 2 and Figure 2 summarize the liquid limit, plastic limit and plastic indexes of peat-kaolin mixture. The liquid limit and plastic limit of peat-kaolin are improved. The kaolin mineralogy is improved liquid limit and plastic limit. And new minerals are developed because of kaolin subjected to heat this accelerates improving liquid limit and plastic limit of peat-kaolin. The mechanical property of kaolinite is changed due to submitted to 500°C heat based on the previous study (Abdoullah and Suresh, 2011). We applied 200°C, 400°C, 600°C and 800°C of heat to kaolin and resulted in accelerate improving liquid limit and plastic limit due to creation of new minerals which can help in solving some geotechnical engineering problems.

Table 1: Mechanical properties of peat

Figure 1: Particle size distribution curve of peat

Table 2: Results of liquid limit and plastic limit of kaolin-peat mixture

Properties Peat soil

Liquid Limit (%) Plastic Limit (%)

Plasticity Index (%) Gravel (%) Sand (%) Silt (%)

Clay (%) Density (kg/m3)

Soil Type (USCS) Description

38.59 29.36 9.23

0 70 29 1

1655.69 SM

Silty Sand

Peat Kaolin Liquid Limit (%)

Plastic limit (%)

Plastic index (%)

Peat 100% - 38.59 29.36 9.23

Peat + Kaolin (0°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

39.81 40.05 43.99 46.65 51.64

34.01 38.79 40.71 43.31 47.98

5.80 1.26 3.28 3.00 3.66

Peat + Kaolin (200°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

38.48 41.35 44.13 46.65 50.44

34.41 37.17 41.69 42.71 44.62

4.07 4.18 2.44 3.94 5.82

Peat + Kaolin (400°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

37.38 42.22 45.49 46.72 47.42

31.31 37.04 40.76 41.61 42.92

6.07 5.18 4.73 5.11 4.50

Peat + Kaolin (600°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

39.94 45.2

50.17 54.78 57.08

31.31 41.70 46.16 52.12 52.15

8.45 3.50 4.01 2.66 4.93

Peat + Kaolin (800°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

41.78 47.14 54.26 60.55 66.72

36.22 38.11 51.77 56.05 61.23

5.56 9.03 2.49 4.50 5.49

International Journal of Civil Engineering & Geo-Environmental 3 (2012) ______________________________________________________________________________________________________

26

Figure 3: Standard proctor compaction result of mixed soil. Figure 4: XRD result of raw Kaolin and thermally heated Kaolin

Figure 5: XRD analysis of mixed soils for 50% ratio

Figure 4 illustrates the XRD analysis of kaolin, and it shows new minerals are developed when the kaolin is subjected to heat. It is highlighted the new mineral was figured when the kaolin subjected to 400°C and 600°C. The unknown mineral is appeared when kaolin subjected to 800°C which means new unidentified minerals was formed when kaolin subjected to very high temperature. As a result, thermally heated kaolin can improve liquid limit and plastic limit of peat-kaolin mixture which can help in solving some geotechnical engineering problems. The mechanical property of kaolinite is changed due to submitted to 500°C heat based on the previous study (Abdoullah and Suresh, 2011).

Figure 5 shows the XRD analysis of peat-kaolin mixture samples for each 50% proportion. Based on the previous discussion of liquid limit and plastic limit, the trends of data will go higher when the mixture is 50:50. However, the XRD cannot analyze the minerals present when the peat and kaolin is mixed together. Due to this case, the samples should be analyzed by using Nuclear Magnetic Resonance (NMR) and Field Emission Scanning Electron Microscopy (FESEM) to get detail on chemical composition and morphology of soils. However, further study on peat-kaolin mixture is required for assessing specimen shear strength, bearing capacity, settlement and deformation. 4. Conclusion Based on the result and findings from this research, it can be concluded that:

1. In this research work has been found that in mixed soil process, by heat treated kaolin, is improved peat liquid limit and plastic limit.

2. Modifying kaolin mineralogy in high temperature level is accelerated improving peat liquid limit and plastic limit.

3. Mixing unheated kaolin to peat is resulted in maximum level for enhancing specimen dry density while modifying kaolin mineralogy in high degree of

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700

unheated

200oC

400oC

600oC

800oC

Dry

den

sity

(kg

/m3 )

Percentage of kaolin (%)

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700 600oC 10%

600oC 20%

600oC 30%

600oC 40%

Dry

den

sity

(kg

/m3 )

Moisture content (%)

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700 800oC 10%

800oC 20%

800oC 40%

Dry

den

sity

(kg

/m3 )

Moisture content (%)

International Journal of Civil Engineering & Geo-Environmental 3 (2012) ______________________________________________________________________________________________________

24

1E-4 1E-3 0.01 0.1 10

20

40

60

80

100

Cum

ula

tive p

erc

enta

ge (

%)

Particle size (mm)

This is an investigation for improving some mechanical properties of peat by using natural mineral as additive. 2. Methodology The peat soil has been collected from Jalan Kuantan-Pekan, Pahang with a coordinate of longitude 103.301239E and latitude 3.650854N. The area was well-known with the problematic soil. The peat in that area was formed by decaying of vegetation in clayey or sandy soils. The sample was collected in mentioned area and has been mixed with unheated Kaolin and, heated Kaolin which was subjected to 200°C, 400°C, 600°C and 800°C heat. The mixture proportion of peat with each of unheated and heated Kaolin were 90:10, 80:20, 70:30, 60:40 and 50:50. The liquid limit, plastic limit, sieve analysis and standard proctor tests have been performed.

The liquid limit, plastic limit, sieve analysis and standard proctor tests have been performed. All tests were carrying out using BS 1377. Mineralogical analyses only been performed for percentage mixture of peat with the raw and thermally heated kaolin samples that attain maximum result for liquid limit and plastic limit by using X-ray diffraction instrument in UMP FIST laboratory. This is due to obtain the behavior of mixed samples when it under wet conditions. 3. Result and discussion

The mixed soil technique had been studied by several researchers. The soil mechanical properties and particle size distribution of peat soil are showed in Table 1 and Figure 1, respectively. The peat has low plasticity. The Figure 1 is indicated that the soil is well-graded and sand is a major proportion. Table 2 and Figure 2 summarize the liquid limit, plastic limit and plastic indexes of peat-kaolin mixture. The liquid limit and plastic limit of peat-kaolin are improved. The kaolin mineralogy is improved liquid limit and plastic limit. And new minerals are developed because of kaolin subjected to heat this accelerates improving liquid limit and plastic limit of peat-kaolin. The mechanical property of kaolinite is changed due to submitted to 500°C heat based on the previous study (Abdoullah and Suresh, 2011). We applied 200°C, 400°C, 600°C and 800°C of heat to kaolin and resulted in accelerate improving liquid limit and plastic limit due to creation of new minerals which can help in solving some geotechnical engineering problems.

Table 1: Mechanical properties of peat

Figure 1: Particle size distribution curve of peat

Table 2: Results of liquid limit and plastic limit of kaolin-peat mixture

Properties Peat soil

Liquid Limit (%) Plastic Limit (%)

Plasticity Index (%) Gravel (%) Sand (%) Silt (%)

Clay (%) Density (kg/m3)

Soil Type (USCS) Description

38.59 29.36 9.23

0 70 29 1

1655.69 SM

Silty Sand

Peat Kaolin Liquid Limit (%)

Plastic limit (%)

Plastic index (%)

Peat 100% - 38.59 29.36 9.23

Peat + Kaolin (0°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

39.81 40.05 43.99 46.65 51.64

34.01 38.79 40.71 43.31 47.98

5.80 1.26 3.28 3.00 3.66

Peat + Kaolin (200°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

38.48 41.35 44.13 46.65 50.44

34.41 37.17 41.69 42.71 44.62

4.07 4.18 2.44 3.94 5.82

Peat + Kaolin (400°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

37.38 42.22 45.49 46.72 47.42

31.31 37.04 40.76 41.61 42.92

6.07 5.18 4.73 5.11 4.50

Peat + Kaolin (600°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

39.94 45.2

50.17 54.78 57.08

31.31 41.70 46.16 52.12 52.15

8.45 3.50 4.01 2.66 4.93

Peat + Kaolin (800°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

41.78 47.14 54.26 60.55 66.72

36.22 38.11 51.77 56.05 61.23

5.56 9.03 2.49 4.50 5.49

Improving Peat Engineering Properties by Natural Mineral Mixture

25

Figure 2: Results of liquid limit and plastic limit of kaolin-peat mixture

Figure 2: Results of liquid limit and plastic limit of kaolin-peat mixture

Table 3 and Figure 3 contain dry density of mixed

soil and illustrated mixed soil proportion. The density of peat soil as indicated in Table 1 is 1655.69 kg/m3. The experimental is identified that, the mixture of unheated kaolin with peat improve 3% of dry density. The investigation shows increasing heat in modifying kaolin lead to decrease of density and increasing proportion of kaolin in mixture specimen also reduces density. Although the increment of changing density is not too high but previous study is highlighted that the shear strength of kaolin when treated by heat increases due to increasing cohesion and internal angle of friction even the density is reduced (Abdoullah and Suresh, 2011) but that investigation was kaolin submitted to 500°C heat and it was not mixed to any soil.

The density of mixed soil is reducing because

moisture in crystal of kaolin is vaporized. However, further study on peat-kaolin mixture is required for assessing specimen shear strength, bearing capacity, settlement and deformation.

Peat Kaolin Optimum Moisture Content

(%)

Dry Density (kg/m3)

Peat + Kaolin (0°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

17.90 16.47 17.04 19.79 24.15

1693.17 1707.52 1684.88 1641.15 1591.07

Peat + Kaolin (200°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

18.51 17.47 21.93 20.81 25.47

1688.13 1664.88 1628.19 1633.64 1535.61

Peat + Kaolin (400°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

19.54 19.19 23.09 23.63 27.84

1674.44 1636.88 1595.83 1548.56 1469.62

Peat + Kaolin (600°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

24.31 27.22 31.22 33.49

-

1543.00 1485.36 1388.65 1320.91

-

Peat + Kaolin (800°C)

90% 80% 70% 60% 50%

10% 20% 30% 40% 50%

26.58 29.50

- 37.79

-

1508.89 1426.32

- 1312.13

-

Table 3: Results of optimum moisture content and dry density of mixed soil

10 20 30 40 5025

30

35

40

45

50

55

60

65

70 unheated

200oC

400oC

600oC

800oC Peat Plastic Limit

Liqu

id L

imit

(%)

Moisture Content (%)

10 20 30 40 5025

30

35

40

45

50

55

60

65

70 unheated

200oC

400oC

600oC

800oC peat plastic limit

Plas

tic L

imit

(%)

percentage mixture (%)

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700

unheated 10% unheated 20% unheated 30% unheated 40% unheated 50%

Dry

Den

sity

(kg

/m3 )

Moisture content (%)

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700

200oC 10%

200oC 20%

200oC 30%

200oC 40%

200oC 50%

Dry

Den

sity

(kg

/m3 )

Moisture content (%)

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700 400oC 10%

400oC 20%

400oC 30%

400oC 40%

400oC 50%

Dry

den

sity

(kg

/m3 )

Moisture content (%)

International Journal of Civil Engineering & Geo-Environmental 3 (2012) ______________________________________________________________________________________________________

26

Figure 3: Standard proctor compaction result of mixed soil. Figure 4: XRD result of raw Kaolin and thermally heated Kaolin

Figure 5: XRD analysis of mixed soils for 50% ratio

Figure 4 illustrates the XRD analysis of kaolin, and it shows new minerals are developed when the kaolin is subjected to heat. It is highlighted the new mineral was figured when the kaolin subjected to 400°C and 600°C. The unknown mineral is appeared when kaolin subjected to 800°C which means new unidentified minerals was formed when kaolin subjected to very high temperature. As a result, thermally heated kaolin can improve liquid limit and plastic limit of peat-kaolin mixture which can help in solving some geotechnical engineering problems. The mechanical property of kaolinite is changed due to submitted to 500°C heat based on the previous study (Abdoullah and Suresh, 2011).

Figure 5 shows the XRD analysis of peat-kaolin mixture samples for each 50% proportion. Based on the previous discussion of liquid limit and plastic limit, the trends of data will go higher when the mixture is 50:50. However, the XRD cannot analyze the minerals present when the peat and kaolin is mixed together. Due to this case, the samples should be analyzed by using Nuclear Magnetic Resonance (NMR) and Field Emission Scanning Electron Microscopy (FESEM) to get detail on chemical composition and morphology of soils. However, further study on peat-kaolin mixture is required for assessing specimen shear strength, bearing capacity, settlement and deformation. 4. Conclusion Based on the result and findings from this research, it can be concluded that:

1. In this research work has been found that in mixed soil process, by heat treated kaolin, is improved peat liquid limit and plastic limit.

2. Modifying kaolin mineralogy in high temperature level is accelerated improving peat liquid limit and plastic limit.

3. Mixing unheated kaolin to peat is resulted in maximum level for enhancing specimen dry density while modifying kaolin mineralogy in high degree of

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700

unheated

200oC

400oC

600oC

800oC

Dry

den

sity

(kg

/m3 )

Percentage of kaolin (%)

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700 600oC 10%

600oC 20%

600oC 30%

600oC 40%

Dry

den

sity

(kg

/m3 )

Moisture content (%)

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700 800oC 10%

800oC 20%

800oC 40%

Dry

den

sity

(kg

/m3 )

Moisture content (%)

International Journal of Civil Engineering & Geo-Environmental 3 (2012) ______________________________________________________________________________________________________

26

Figure 3: Standard proctor compaction result of mixed soil. Figure 4: XRD result of raw Kaolin and thermally heated Kaolin

Figure 5: XRD analysis of mixed soils for 50% ratio

Figure 4 illustrates the XRD analysis of kaolin, and it shows new minerals are developed when the kaolin is subjected to heat. It is highlighted the new mineral was figured when the kaolin subjected to 400°C and 600°C. The unknown mineral is appeared when kaolin subjected to 800°C which means new unidentified minerals was formed when kaolin subjected to very high temperature. As a result, thermally heated kaolin can improve liquid limit and plastic limit of peat-kaolin mixture which can help in solving some geotechnical engineering problems. The mechanical property of kaolinite is changed due to submitted to 500°C heat based on the previous study (Abdoullah and Suresh, 2011).

Figure 5 shows the XRD analysis of peat-kaolin mixture samples for each 50% proportion. Based on the previous discussion of liquid limit and plastic limit, the trends of data will go higher when the mixture is 50:50. However, the XRD cannot analyze the minerals present when the peat and kaolin is mixed together. Due to this case, the samples should be analyzed by using Nuclear Magnetic Resonance (NMR) and Field Emission Scanning Electron Microscopy (FESEM) to get detail on chemical composition and morphology of soils. However, further study on peat-kaolin mixture is required for assessing specimen shear strength, bearing capacity, settlement and deformation. 4. Conclusion Based on the result and findings from this research, it can be concluded that:

1. In this research work has been found that in mixed soil process, by heat treated kaolin, is improved peat liquid limit and plastic limit.

2. Modifying kaolin mineralogy in high temperature level is accelerated improving peat liquid limit and plastic limit.

3. Mixing unheated kaolin to peat is resulted in maximum level for enhancing specimen dry density while modifying kaolin mineralogy in high degree of

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700

unheated

200oC

400oC

600oC

800oC

Dry

den

sity

(kg

/m3 )

Percentage of kaolin (%)

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700 600oC 10%

600oC 20%

600oC 30%

600oC 40%

Dry

den

sity

(kg

/m3 )

Moisture content (%)

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700 800oC 10%

800oC 20%

800oC 40%

Dry

den

sity

(kg

/m3 )

Moisture content (%)

International Journal of Civil Engineering & Geo-Environmental 3 (2012) ______________________________________________________________________________________________________

26

Figure 3: Standard proctor compaction result of mixed soil. Figure 4: XRD result of raw Kaolin and thermally heated Kaolin

Figure 5: XRD analysis of mixed soils for 50% ratio

Figure 4 illustrates the XRD analysis of kaolin, and it shows new minerals are developed when the kaolin is subjected to heat. It is highlighted the new mineral was figured when the kaolin subjected to 400°C and 600°C. The unknown mineral is appeared when kaolin subjected to 800°C which means new unidentified minerals was formed when kaolin subjected to very high temperature. As a result, thermally heated kaolin can improve liquid limit and plastic limit of peat-kaolin mixture which can help in solving some geotechnical engineering problems. The mechanical property of kaolinite is changed due to submitted to 500°C heat based on the previous study (Abdoullah and Suresh, 2011).

Figure 5 shows the XRD analysis of peat-kaolin mixture samples for each 50% proportion. Based on the previous discussion of liquid limit and plastic limit, the trends of data will go higher when the mixture is 50:50. However, the XRD cannot analyze the minerals present when the peat and kaolin is mixed together. Due to this case, the samples should be analyzed by using Nuclear Magnetic Resonance (NMR) and Field Emission Scanning Electron Microscopy (FESEM) to get detail on chemical composition and morphology of soils. However, further study on peat-kaolin mixture is required for assessing specimen shear strength, bearing capacity, settlement and deformation. 4. Conclusion Based on the result and findings from this research, it can be concluded that:

1. In this research work has been found that in mixed soil process, by heat treated kaolin, is improved peat liquid limit and plastic limit.

2. Modifying kaolin mineralogy in high temperature level is accelerated improving peat liquid limit and plastic limit.

3. Mixing unheated kaolin to peat is resulted in maximum level for enhancing specimen dry density while modifying kaolin mineralogy in high degree of

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700

unheated

200oC

400oC

600oC

800oC

Dry

den

sity

(kg

/m3 )

Percentage of kaolin (%)

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700 600oC 10%

600oC 20%

600oC 30%

600oC 40%

Dry

den

sity

(kg

/m3 )

Moisture content (%)

5 10 15 20 25 30 35 40 45 501100

1200

1300

1400

1500

1600

1700 800oC 10%

800oC 20%

800oC 40%

Dry

den

sity

(kg

/m3 )

Moisture content (%)

Improving Peat Engineering Properties by Natural Mineral Mixture

27

temperature is reduced specimen dry density. It is expected to improve peaty subsoil allowable deformation by using this technique.

4. New minerals presence in thermally heated kaolin subjected to improve the liquidity and plasticity of weak soils. The weak soils became more stabilize due to existence of unknown minerals that should be identified by more advance equipment.

5. Analyzing mineralogy of mixed soils using XRD instrument could not give sufficient result of minerals that present in peat-kaolin soils. The investigation of micro properties and morphology of soils should be investigating using NMR and FESEM experimental equipment.

6. The micro and macro properties study on kaolin and kaolin-peat are required and also the more investigations are needed for assessing specimen shear strength, bearing capacity, settlement and deformation.

7. The application of this research work is for low cost ground improvement due to mix with natural minerals resource soil and enhancing subsoil bearing capacity, while is one of important geotechnical problem and responsible for many subsoil and earth structure failure.

References

Abdoullah N. and Suresh N., (2011). Evaluation of

Slope Reliability, Kaolinite Thermal Evaluation in Geotechnical Engineering, Advance in National Applied Science, 5(2), 85-92.

Anon, (1978). Specifications for road works Department of Environment Stationary Office. Dublin.

Charman D. J., (2002). Peatland systems and environmental change. John Wiley & Sons, Chichester. 301.

Davitt S. and Killeen R.C., (1996). Maintenance techniques for bog roads. National Roads Authority (NRA) report RC. 375NRA, Dublin.

Hampson D. M., (1993). Constructing low cost un- surfaced roads. Forestry Eng Specialist Group Heriot Watt University, Edinburgh.

Hashim R., (2003). Properties of Stabilized Peat by Soil-Cement Column Method, EJGE, vol. 13, 1-9.

Huat B. B. K., Kazemian S., and Kuang W. L., (2011) “Effect of Cement-Sodium Silicate Grout and Kaolinite on Undrained Shear Strength of Reinforced Peat,” EDGE, vol. 16, no. Bund. K, 1221-1228.

Larsson S., Rothhämel M., and G. Jacks, (2009). A laboratory study on strength loss in kaolin surrounding lime–cement columns,” Applied Clay Science, vol. 44, no. 1-2, 116-126.

Mutalib A. A., Lim J. S., Wong M. H. and Koonvai L., 1991, Characterization, distribution and utilization of peat in Malaysia. Proc. Int. Syrup, May. 1991 Tropical Peat land, Kuching, Malaysia.

MacFarlane I.C., (1969), Muskeg engineering handbook University of Toronto Press, Toronto.

Toh C.T., Chee S. K., Lee C. H., and Wee S. H., (1994). Geotextile-bamboo fascine mattress for filling over very soft soils in Malaysia. Engineering, 13, 357-369.