Modification of Expansive Clay Soil Using Fibre and Cement in Combined Measures for Highway Pavement

GSJ: Volume 8, Issue 1, January 2020 ISSN 2320-9186 2691

GSJ: Volume 8, Issue 1, January 2020, Online: ISSN 2320-9186 www.globalscientificjournal.com

Modification of Expansive Clay Soil using Fibre and Cement in Combined Measures for Highway Pavement

Gabriel Okonkwo Nnaji1, Charles Kennedy2, Paschal Agha Mbeyi3.

1Department of Civil Engineering, Enugu State University of Science and Technology, Enugu. 2Department of Civil Engineering, Faculty of Engineering, Rivers State University, Port Harcourt - Rivers State, Nigeria 3Civil Engineering Technology Department, Akanuibiam Federal Polytechnic Uwana Afikpo, Ebonyi State, Nigeria

Authors E-mail:, [email protected], [email protected],

ABSTRACT

The research work assessed the possible modification of expansive soft clay soils of low and weak geotechnical parameters with irvinga gabonesis fibre + cement at 0.25% +2.5%. 0.5% + 5.0%, 0.75% + 7.5% and 1.0% + 10% to soils corresponding percentage ratios. The soils are classified as A – 7 – 6 /CH on the AASHTO classification schemes / Unified Soil Classification System. The soils are dark grey (from wet to dry states) with a plastic index of 31.10%, 24.55%, 31.05%, and 32.17%. The soils has unsoaked CBR values of 7.35%, 7.75%, 8.15%, and 7.85% and soaked CBR values of 6.35%, 6.23%, 7.05% and 5.55%. Unconfined compressive strength (UCS) values of 87.85kPa, 78.75kPa, 105.75kPa, and 85.35kPa at preliminary investigations. Verifiable results of un-stabilized and stabilized results showed tremendously increased in compaction parameters of MDD and OMC to varying percentages. Comparably, results indicated increased in CBR altered soils with optimum mixed percentage ratios of 0.7% to soils. Stabilized clay soils increased in CBR values with an increase in additives percentages to optimum mix ration 0.75% + 7.5%. Dropped in were noticed beyond the optimum mix. Results indicated an increase in UCS with ratio increase to corresponding soils percentages. Results indicated a reduction in the plastic index to increase in corresponding percentage ratios. The entire results indicated the potential of using additives in combine state for weak soil treatment. Key Words: Clay soils, Irvinga Gabonesis Fibre, Cement, CBR, UCS, Consistency, Compaction

1.0 INTRODUCTION Soil stabilization mainly relies on chemical reactions between stabilizers (cementitious additives) and clay minerals to achieve the desired standard for the embankment of highway pavements and is

indicated by FMW specifications (1997). Generally, for the expansion of natural (bitumen) or inorganic (cement or lime) chemical compounds, the ability to disperse the soil and increase the hardness of the soil. Their function is to reduce plasticity and facilitate density. The change of the index properties of the soil by adding chemicals such as cement, cement kiln dust, fly ash, lime or a combination thereof, often alters the physical and chemical properties of the soil, including the cementation of the clay particles. Charles et al. (2018) evaluated the geotechnical properties of an expansive soil found along the Odioku - Odiereke roads in the Niger State of Ahoada -West, Rivers State. Application of two cement agents of hybridized cement and lime with costus afer bagasse fiber to strengthen the failing section of the road. Preliminary investigation values indicate that the soil is highly plastic. The results showed the ability to use bagasse, BSBF as lime in cement and used lime clay soil and laterite with optimum values of 8% cement and lime and 7.5% + 7.5% cement/lime + BSBF. Akobo et al. (2018) evaluated the application of agricultural waste materials of plantain rachis fibers, hybridized with cement and lime and modified the engineering properties of the vast laterite soil. The comparative strength of un-stabilized and stabilized soils with composite materials, the results of compaction tests showed that mixed soil-stabilized soils have a maximum dry density (MDD) and optimum moisture content (OMC) of soil incorporating composite stabilizers agents displayed incremental percentage values for soils with varying percentage ratios. Computed results of the California bearing ratio (CBR) of stabilized and soaked soils with stabilizing agents of cement, lime, and PRF indicate a percentile value increase for the relatively additive to the optimal mixing ratio of 91.75 + 0.75 + 7.5%. Unconfined compressive strength test results of soils stabilized with cementitious agents of cement/lime + PRF showed an incremental percentage value as the ratio of additives to soils in the test results. Barisua et al. (2018) evaluated the differential strength of expanded clay soils with swelling - shrinkage characteristics on the application of two cementitious stabilizing agents of cement and lime in combination with Bagasse fiber fibers of pozzolanic characteristics for agricultural products of costaceous leucerus. The obtained results of the unconfined compressive strength test showed incremental percentile values for the cement/lime + CLBFA combination with cement to lime in higher values. Wikina et al. (2018) evaluated the engineering behavioral characteristics of stable extensional laterite soils with cement, lime and Irvinga gabonisis fibers, their combined strength characteristics.

Percentile descriptive statistical tests of sampled roads maximum dry density (MDD) and optimum moisture content (OMC) are Odioku, 1.006% and 1.010%, Oyigba 1.012%, and 1.022%, Anakpo 1.013% and 1.014%, Upatabo 1.010% and 1.025%, Ihubuluko 1.011% and 1.024% respectively of MDD and OMC at 100% natural soils. The comparatively un-stable and mixed-stable soil maximum dry density (MDD) and the optimum moisture content (OMC) of the compaction test parameters reflect the percentage increase in the percentage ratio of mixed stabilizers in the soil. Charles et al. (2018) investigated the problematic engineering properties of soils with high plasticity levels, high swelling and shrinkage potentials used in pavement design in the Nigerian Niger Delta region. The application of stabilizing agents of cement and costus afer bagasse fiber (bush cane bagasse fiber) was mixed into a single and combines functions to improve their unique properties. The results showed that the material stabilizing the inclusions had improved soil strength. The results of the tests conducted showed that the optimum moisture content increased with increasing cement ratio in both soil (clay) and (laterite). The soil treated with cement decreased in the liquid limit and the plastic limit increased. Soil with cement and fiber products in combination increased CBR values and appreciated both in hanging conditions. At 8% lime, the CBR value reached the optimum, beyond this limit; cracks are present and 7.5% cement + 0. 75% BSBF, reaching the optimum value. Sabat (2012) studied the effects of polypropylene fibers on the engineering properties of RHA-Lime. Polypropylene fibers were added 0.5% to 2% at a 0.5% increase. The determined properties were condensation, the effect of UCS, soaked CBR, hydraulic conductivity and P soaking of 0-day, 7-day and 28-day curing vessels were also studied by UCS. CBR, hydraulic conductivity and swelling pressure. The optimum soil ratio: RHA: lime: fiber was found to be 84.5: 10: 4: 1.5. Ramakrishna and Pradeep (2006) studied the combined effects of RHA and cement on the engineering properties of black cotton soil. From the strength characteristics point of view, they recommended 8% cement and 10% RHA as the optimal dosage for stabilization. Charles et al. (2018) examined the contributive improvement on expansive lateritic soils with less matured characteristics, sensitive to manipulations by many forms with hybridized composite materials of cement + costaceae lacerus bagasse fibre and lime + costaceae lacerus bagasse fibre, their varying strengths and the behavioral attributes for soil modifications. Stabilized soils maximum dry density (MDD) and optimum moisture content (OMC) demonstrated incremental percentile values with an increase in composite stabilizers' inclusion percentages ratio to soils. Unconfined

compressive strength test of stabilized soils with cement/lime + CLBF showed incremental percentile relatively to the percentage ratios to stabilizers and soils. Sharma et al. (2008) investigated stable soil behavior with lime, calcium chloride, and RHA. The optimal percentage of lime and calcium chloride addition to RHA was found to be 4% and 1%, respectively, in the stabilization of the soil without expansion. From the viewpoint of UCS and CBR, when the soil was mixed with lime or calcium chloride, and RHA content of 12% was found to be optimal. In expanded soils - RHA mix, 4% lime and 1% calcium chloride were also found to be optimal. Amakiri - White et al. (2018) evaluated the applications of composite materials of cement + plantain rachis fibers and lime + plantain rachis fibers and their performance characteristics for large clay soil amendments. Comparative results of clay soils under natural conditions and composite stabilized clay soils compaction test results of maximum dry density (MDD) and optimum moisture content (OMC) possessed incremental percentile values concerning the rate of percentages ratio increase to soils. Demonstrated for the strength variance of cement performed. And lime with PRF structure with high performance. The combined results of the comparative results of unconfined compressive strength tests of cemented materials showed incremental percentage values according to the percentage increase of composite material to clay ratio with cement performance in higher values of lime. Terence et al. (2018) investigated and evaluated the application of Costaceae lacaceous bagasse fiber ash in combination with cement and lime in a variation in mix ratio and detected variation in strengths. The vast soils within the Niger Delta region have presented great concerns and challenges for civil engineering construction operations and have limited their design specifications, life span, and durability, thus, modifications to improve its properties and required strength. The California bearing ratio (CBR) of un-soaked and soaked soils with mixed content of cement, lime and CLBFA to include a percentage ratio with an optimum mixing ratio of 85% + 7.5 + 7.5% gives a relatively incremental percentage yield. Incremental percentage values appeared as a proportion of the increase in soil with an increase in the results of unconfined compressive strength tests from unstable and stable soils with cement/lime + CLBFA. Ode et al. (2018) investigated the incremental and reductive percentile values of problematic clay soils treated with cement, lime, and Irvinga gabonisis fibers with combination variance and strength variance comparisons of cement percentage in the combined works. The results of compaction tests showed an incremental percentage value of maximum dry density (MDD) and optimum moisture

content (OMC) of mixed expansive soils hybridized with cement/lime + IGF with an increase in soil compaction ratio. The result of unconfined compressive strength of stable clay soils mixed with cement/lime + IGF showed an incremental percentage value concerning the percentage of composite mixing ratio with peak values recorded in cement over lime. Charles et al. (2018) evaluated the application of cementitious stabilizing agents of cement/lime and plantain rachis fiber ash in joint works and compared their strength variance to clay soil amendments in comparison. Comparison of maximum dry density (MDD) and optimum moisture content (OMC) in the test of condensation with cement and lime cementitious agents compared with natural and stable conditions with the same percentage ratio in the soil with the same percentage ratio with PRFA An increase in incremental percentage values were observed. Stabilized soils have increased the results of soil uninfected strength tests, which combine relatively incremental values in percentage of the average material, including the composite material in soils with cement composition at high levels of lime 2.0 MATERIALS AND METHODS 2.1 Materials 2.1.1 Soil Sampled soil are gotten at failed sections of highway of the at 1.5 m depth from Iwofe Town Road, in Obio/Akpor Local Government Area, Chokocho Town Road, in Etche Local Government Area, Ndoni Town Road, in Ogba/Egbema/Ndoni Local Government Area and Ogbele Town Road in Ahoada – East Local Government Area, all in Rivers State, Nigeria. 2.1.2 Irvinga Gabonesis Fibre The Irvinga Gabonesis, are collected from Olokuma village, a riverside area in Ubie Clan, Ahoada- West, Rivers State, Nigeria. 2.1.3 Cement The cement used was purchased in, Port Harcourt, Rivers State 2.2 METHOD 2.2.1 Sampling Locality Sampled soils are gotten along Iwofe Town, (latitude 4.49° 41‘S and longitude 6.57° 24‘E), Chokocho Town, ( latitude 4.9882° N ° 34‘S and longitude 7.0525° ° 13‘E), Ndoni Town, latitude 5.5487 ° 21‘S and longitude 6.5917° ° 39‘E), Ogbele Town, (latitude 4.9198 ° 23‘S and longitude 6.6751 ° 34‘E) all in Rivers State, Nigeria.

2.2.2 Test Conducted Test conducted were (1) Moisture Content Determination (2) Consistency limits test (3) Particle size distribution (sieve analysis) and (4) Standard Proctor Compaction test, California Bearing Ratio test (CBR) and Unconfined compressive strength (UCS) tests; 2.2.3 Moisture Content Determination This laboratory test is performed to determine the relationship between moisture content and soil dry density for a specified compact effort

2.2.4 Grain Size Analysis (Sieve Analysis) This test is performed to determine the percentage of different grain sizes contained within the soil. The mechanical or sieve analysis is performed to determine the distribution of the coarser, larger- sized particles. 2.2.5 Consistency Limits The liquid limit (LL) is arbitrarily defined as the water content, in percent, at which a part of soil in a standard cup and cut by a groove of standard dimensions will flow together at the base of the groove for a distance of 13 mm (1/2in.) when subjected to 25 shocks from the cup being dropped 10 mm in a standard liquid limit apparatus operated at a rate of two shocks per second. 2.2.6 Moisture – Density (Compaction) Test This laboratory test is performed to determine the relationship between the moisture content and the dry density of a soil for a specified compaction effort. 2.2.7 Unconfined Compression (UC) Test The unconfined compressive strength is taken as the maximum load attained per unit area, or the load per unit area at 15% axial strain, whichever occurs first during the performance of a test. The primary purpose of this test is to determine the unconfined compressive strength, which is then used to calculate the unconsolidated undrained shear strength of the clay under unconfined conditions. 2.2.8 California Bearing Ratio (CBR) Test The California Bearing Ratio (CBR) test was developed by the California Division of Highways as a way to reevaluate and evaluate soil-suburb and base course materials for flexible pavements. 3.0 RESULTS AND DISCUSSIONS The detailed test results showed that the physical and engineering properties of the lateritic soils fall below the minimum requirement for such application and stabilization was required to improve its

properties. is. Soils classified as A-2-6 SC and A-2-4 SM on the AASHTO classification schemes / integrated soil classification system are shown in Table 3.1 and are less mature in the soil vertical profile and possibly more susceptible to all forms of manipulation that other deltaic lateritic soils are known for (Ola 1974; Allam and Sridharan 1981; Omotosho and Akinmusuru 1992; Omotosho 1993). The soils are reddish brown and dark grey in colour (from wet to dry states) plasticity index of 31.10%, 24.55%, 31.05%, and 32.17% respectively for Iwofe, Chokocho, Ndoni, and Ogbele Town Roads. The soil has unsoaked CBR values of 7.35%, 7.75%, 8.15%, and 7.85% and soaked CBR values of 6.35%, 6.23%, 7.05% and 5.55%, unconfined compressive strength (UCS) values of 87.85kPa , 78.75kPa, 105.75kPa , and 85.35kPa when compacted with British Standard light (BSL), respectively 3.1 Compaction Test Results Compaction tests results of clay soils at 100% of maximum dry density (MDD) at preliminary test 1.685KN/m3, 1.635KN/m3, 1.657KN/m3, 1.697KN/m3 and optimum moisture content (OMC) are 15.28%, 16.28%, 16.05% and 15.73% at respective sites and locations. Stabilized clay soils with Irvinga gabonesis fibre + cement with ratios shown in table 3.1 maximum value results of MDD are 2.065 KN/m3, 1.808 KN/m3, 1.842 KN/m3, 1.823 KN/m3 with maximum percentile incremental values from 95.46742%, 99.87783% , 98.16351% - 98.95044% t o 111.1648%, 110.581% 122.5519%, and 107.4249%. OMC values are 16.75%, 17.15%, 17.35%, and 16.83% having percentile peak increased from 99.2429%, 98.78641%, 98.10513%, 97.63578% to 106.993%, 105.344%,108.0997%, 109.6204% .Verifiable results of un-stabilized and stabilized results showed tremendously increased of compaction parameters of MDD and OMC to varying percentages. 3.2 California Bearing Ratio (CBR) Test Clay soils results at 100% unsoaked are7.35%, 7.75%, 8.15%, 7.85% and soaked are 6.35%, 6.23%, 7.05% and 5.55% at preliminary test. Stabilized clay soils with Irvinga gabonesis fibre + cement with 0.25% +2.5%. 0.5% + 5.0%, 0.75% + 7.5% and 1.0% + 10% to clay soils percentage values at maximum are unsoaked 76.35%, 78.85%, 82.45%, 73.45%, representing percentile increased from 27.238037%, 25.98056%, 23.72635%, 23.37043% to 1038.776%, 1017.419% , 1011.656%, 935.6688% and soaked are 69.35%, 69.85%, 76.30% and 67.28% with percentile peak increase from 24.7216%, 24.77137%, 24.86772%, 25.09881% to 1092.126%, 1121.188%, 1082.27%, 1212.252% respectively from varying ratio. Comparably, results indicated increased in CBR altered soils with

optimum mixed percentage ratios of 0.7% to soils. Stabilized clay soils increased in CBR values with increase in additives percentages to optimum mix ration 0.75% + 7.5%. Reduction in values in was noticed beyond optimum mix. 3.3 Unconfined Compressive Strength Test Clay soils at preliminary engineering properties at zero percentage are 87.85kPa, 78.75kPa, 105.75kPa and 85.35kPa representing percentage values of 42.52551%, 55.06993%, 51.34951%, and 56.3141%. Modified clay soils with the percentages shown in table 3.4 are 589Pa and 603kPa, 645kPa and 615kPa respectively and represented values increased respectively to 670.461%, 765.7143%, 737.8524%, and 609.7561%. Results indicated increased in UCS with ratio increase to corresponding soils percentages. 3.4 Consistency Limits Test Obtained results of consistency limits (Plastic index) at 100% clay soils are 31.10%, 24.55%, 31.05%, and 32.17% with percentage representations of 100.7516%, 101.6142%, 105.1473%, 104.1876%. Modified clay soils are 28.95%, 23.38%, 28.64% and 30.93% with percentile values reduction of 93.08682%, 95.23422%, 96.14548%, and 92.23833%. Results indicated reduction in plastic index to increase in corresponding percentage ratios.

Table 3.1: Engineering Properties of Soil Samples Location Description IWOFE ROAD CHOKOCHO NDONI ROAD OGBELE ROAD OBIO/AKPOR ROAD ETCHE OGBA/EGBEMA/ AHODA EAST L.G.A L.G.A NDONI L.G.A L.G.A Depth of sampling (m) 1.2 1.2 1.2 1.2 Percentage(%) passing BS sieve #200 76.35 80.25 83.65 78.25 Colour Greyish Greyish Greyish Greyish Specific gravity 2.52 2.58 2.45 2.44 Natural moisture content (%) 42.58 48.35 44.65 44.30 Consistency Limits Liquid limit (%) 68.35 53.85 62.40 58.75 Plastic limit (%) 37.25 29.30 31.35 26.58 Plasticity Index 31.10 24.55 31.05 32.17 AASHTO / Unified Soil Classification A-7-6 / CH A-7-6 / CH A-7-6/ CH A-7-6 / CH System Optimum moisture content (%) 15.28 16.28 16.05 15.73 Maximum dry density (kN/m3) 1.685 1.635 1.657 1.697

COMPACTION CHARACTERISTICS Gravel (%) 0.0 0 0 0 Sand (%) 13.18 12.3 12.8 16.5 Silt (%) 42.3 48.5 42.3 48.2 Clay (%) 44.6 38.2 44.9 35.3 Unconfined compressive strength (kPa) 87.85 78.75 105.75 85.35 California Bearing Capacity (CBR) Unsoaked (%) CBR 7.35 7.75 8.15 7.85 Soaked (%) CBR 6.35 6.23 7.05 5.55 Table 3.2: Results of Subgrade Soil (Clay) Test Stabilization with Binding Cementitious Products at Different Percentages And Combination SAMPLE SOIL + FIBRE

LOCATION IRVINGA 3)

GARBONESIS

kN/m

+ (Kpa)

CEMENT LL(%) PL(%) OMC (%) UNSOAKED CBR (%) CBRSOAKED (%) UCS PI(%) #200 SIEVE / AASHTO USCS (Classification) NOTES MDD (

CLAY SOIL+IRVINGA GARBONESIS FIBRE (IGF) + CEMENT IWOFE 100(%) 1.685 15.28 7.35 6.35 87.85 68.35 37.25 31.10 76.35 A – 7 – 6 /CH POOR ROAD 97.5+0.25+2.5(%) 1.765 15.65 31.45 25.30 156 68.52 38.67 29.85 76.35 A – 7 – 6 /CH GOOD OBIO/AKPO 94.5+0.5+50(%) 1.885 15.93 53.65 48.65 287 68.75 39.30 29.45 76.35 A – 7 – 6 /CH GOOD L.G.A 91.25+0.25+7.5(%) 1.948 16.24 76.35 69.35 338 69.05 39.99 29.06 76.35 A – 7 – 6 /CH GOOD 89+1.0+10(%) 2.065 16.75 63.85 57.82 589 69.38 40.43 28.95 76.35 A – 7 – 6 /CH GOOD CHOKOCHO 100(%) 1.635 16.28 7.75 6.23 78.75 53.85 29.30 24.55 80.25 A – 7 – 6 /CH POOR ROAD 97.5+0.25+2.5(%) 1.637 16.48 29.83 25.15 143 54.06 29.90 24.16 80.25 A – 7 – 6 /CH GOOD ETCHE 94.5+0.5+50(%) 1.728 16.80 57.80 49.30 304 54.35 30.39 23.96 80.25 A – 7 – 6 /CH GOOD L.G.A 91.25+0.25+7.5(%) 1.777 16.94 78.85 69.85 438 54.62 30.88 23.74 80.25 A – 7 – 6 /CH GOOD 89+1.0+10(%) 1.808 17.15 66.37 61.65 603 54.95 31.57 23.38 80.25 A – 7 – 6 /CH GOOD NDONI 100(%) 1.657 16.05 8.15 7.05 105.78 62.40 31.35 31.05 83.65 A – 7 – 6 /CH POOR ROAD 97.5+0.25+2.5(%) 1.688 16.36 34.35 28.35 206 62.78 33.25 29.53 83.65 A – 7 – 6 /CH GOOD OGBA/EGBE 94.5+0.5+50(%) 1.705 16.74 59.35 52.38 315 62.91 198 30.46 83.65 A – 7 – 6 /CH GOOD MA/NDONI 91.25+0.25+7.5(%) 1.758 17.03 82.45 76.30 465 63.05 234 30.05 83.65 A – 7 – 6 /CH GOOD L.G.A 89+1.0+10(%) 1.842 17.35 73.85 69.85 645 63.28 34.64 28.64 83.65 A – 7 – 6 /CH GOOD OGBELE 100(%) 1.697 15.73 7.85 5.55 83.35 58.25 26.58 32.17 78.45 A – 7 – 6 /CH POOR ROAD 97.5+0.25+2.5(%) 1.715 15.85 28.82 22.45 196 58.53 26.60 31.93 78.45 A – 7 – 6 /CH GOOD AHODA 94.5+0.5+50(%) 1.763 16.15 47.45 38.67 289 58.72 27.08 31.64 78.45 A – 7 – 6 /CH GOOD EAST L.G.A 91.25+0.25+7.5(%) 1.795 16.55 73.45 67.28 466 58.93 27.29 31.20 78.45 A – 7 – 6 /CH GOOD 89+1.0+10(%) 1.823 16.83 58.85 52.35 615 59.20 28.27 30.93 78.45 A – 7 – 6 /CH GOOD

Table 3.3: Percentile Combination of Clay Soil + Irvinga Garbonesis Fibre (IGF) + Cement

RATIO % 100% 97.25+0.25 94.5+ 0.5+ 91.75+0.75 +2.5 5.0% +7.5 MAXIMUM DRY DENSITY (MDD(kN/m3) IWOFE ROAD OBIO/AKPO L.G.A , MDD(kN/m3) 1.69 1.77 1.89 1.95 2.07 CHOKOCHO ROAD ETCHE L.G.A , MDD(kN/m3) 1.64 1.64 1.73 1.78 1.81 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , MDD(kN/m3) 1.66 1.69 1.71 1.76 1.84 OGBELE ROAD AHODA EAST L.G.A , MDD(kN/m3) 1.70 1.72 1.76 1.80 1.82 OPTIMUM MOISTURE CONTENT (%) IWOFE ROAD OBIO/AKPO L.G.A, OMC (%) 15.28 15.65 15.93 16.24 16.75 CHOKOCHO ROAD ETCHE L.G.A , OMC (%) 16.28 16.48 16.80 16.94 17.15 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , OMC (%) 16.05 16.36 16.74 17.03 17.35 OGBELE ROAD AHODA EAST L.G.A, OMC (%) 15.73 15.85 16.15 16.55 16.83 CONSISTENCY LIMITS (%) IWOFE ROAD OBIO/AKPO L.G.A, LL(%) 68.35 68.52 68.75 69.05 69.38 IWOFE ROAD OBIO/AKPO L.G.A, PL(%) 37.25 38.67 39.30 39.99 40.43 IWOFE ROAD OBIO/AKPO L.G.A, IP(%) 31.10 29.85 29.45 29.06 28.95 CHOKOCHO ROAD ETCHE L.G.A , LL(%) 53.85 54.06 54.35 54.62 54.95 CHOKOCHO ROAD ETCHE L.G.A , PL(%) 29.30 29.90 30.39 30.88 31.57 CHOKOCHO ROAD ETCHE L.G.A , IP(%) 24.55 24.16 23.96 23.74 23.38 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , LL(%) 62.40 62.78 62.91 63.05 63.28 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , PL(%) 31.35 31.88 32.42 33.00 33.69 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , IP(%) 31.05 29.53 30.46 30.05 28.64 OGBELE ROAD AHODA EAST L.G.A, LL(%) 58.25 58.53 58.72 58.93 59.20 OGBELE ROAD AHODA EAST L.G.A, PL(%) 26.58 26.60 27.08 27.29 28.27 OGBELE ROAD AHODA EAST L.G.A, IP(%) 32.17 31.93 31.64 31.20 30.93 CALIFORNIA BEARING RATIO (%) IWOFE ROAD OBIO/AKPO L.G.A, UNSOAKED CBR(%) 7.35 31.45 76.35 63.85 IWOFE ROAD OBIO/AKPO L.G.A, SOAKED CBR(%) 6.35 25.30 48.65 69.35 57.82 CHOKOCHO ROAD ETCHE L.G.A , UNSOAKED CBR(%) 7.75 29.83 57.80 78.85 66.37 CHOKOCHO ROAD ETCHE L.G.A , SOAKED CBR(%) 6.23 25.15 49.30 69.85 61.65 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , UNSOAKED 8.15 34.35 59.35 82.45 73.85 CBR(%) NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , SOAKED CBR(%) 7.05 28.35 52.38 76.30 69.85 OGBELE ROAD AHODA EAST L.G.A, UNSOAKED CBR(%) 7.85 28.82 47.45 73.45 58.85 OGBELE ROAD AHODA EAST L.G.A, SOAKED CBR(%) 5.55 22.45 38.67 67.28 52.35 UNCONFINED COMPRESSIVE STRENGTH (KPa) IWOFE ROAD OBIO/AKPO L.G.A Soil Unconfined Compressive 87.85 156.00 287.00 338.00 589.00 Strength (kPa) CHOKOCHO ROAD ETCHE L.G.A Soil Unconfined Compressive 78.75 143.00 304.00 438.00 603.00 Strength (kPa) NDONI ROAD OGBA/EGBEMA/NDONI L.G.A Soil Unconfined 105.78 206.00 315.00 465.00 645.00 Compressive Strength (kPa) OGBELE ROAD AHODA EAST L.G.A Soil Unconfined 83.35 196.00 289.00 466.00 615.00 Compressive Strength (kPa)

Table 3.4: Percentile Increase of Clay Soil + Irvinga Garbonesis Fibre (IGF) + Cement

RATIO % 100% 97.25+0.25 94.5+ 0.5+ 91.75+0.75 89+1.0 +2.5 5.0% +7.5 +10% MAXIMUM DRY DENSITY (MDD(kN/m3) IWOFE ROAD OBIO/AKPO L.G.A , MDD(kN/m3) 95.46742 104.7478 111.8694 115.6083 122.5519 CHOKOCHO ROAD ETCHE L.G.A , MDD(kN/m3) 99.87783 100.1223 105.6881 108.685 110.581 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A, 98.16351 101.8709 102.8968 106.0954 111.1648 MDD(kN/m3) OGBELE ROAD AHODA EAST L.G.A , MDD(kN/m3) 98.95044 101.0607 103.8892 105.7749 107.4249 OPTIMUM MOISTURE CONTENT (%) IWOFE ROAD OBIO/AKPO L.G.A, OMC (%) 97.63578 102.4215 104.2539 106.2827 109.6204 CHOKOCHO ROAD ETCHE L.G.A , OMC (%) 98.78641 101.2285 103.1941 104.0541 105.344 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A, OMC (%) 98.10513 101.9315 104.2991 106.1059 108.0997 OGBELE ROAD AHODA EAST L.G.A, OMC (%) 99.2429 100.7629 102.6701 105.213 106.993 CONSISTENCY LIMITS (%) IWOFE ROAD OBIO/AKPO L.G.A, LL(%) 99.7519 100.2487 100.5852 101.0241 101.5069 IWOFE ROAD OBIO/AKPO L.G.A, PL(%) 96.3279 103.8121 105.5034 107.3557 108.5369 IWOFE ROAD OBIO/AKPO L.G.A, IP(%) 104.1876 95.98071 94.69453 93.44051 93.08682 CHOKOCHO ROAD ETCHE L.G.A , LL(%) 99.61154 100.39 100.9285 101.4299 102.0427 CHOKOCHO ROAD ETCHE L.G.A , PL(%) 97.99331 102.0478 103.7201 105.3925 107.7474 CHOKOCHO ROAD ETCHE L.G.A , IP(%) 101.6142 98.41141 97.59674 96.70061 95.23422 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , LL(%) 99.39471 100.609 100.8173 101.0417 101.4103 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , PL(%) 98.33752 101.6906 103.4131 105.2632 107.4641 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , IP(%) 105.1473 95.10467 98.09984 96.77939 92.23833 OGBELE ROAD AHODA EAST L.G.A, LL(%) 99.52161 100.4807 100.8069 101.1674 101.6309 OGBELE ROAD AHODA EAST L.G.A, PL(%) 99.92481 100.0752 101.8811 102.6712 106.3582 OGBELE ROAD AHODA EAST L.G.A, IP(%) 100.7516 99.25396 98.3525 96.98477 96.14548 CALIFORNIA BEARING RATIO (%) IWOFE ROAD OBIO/AKPO L.G.A, UNSOAKED CBR(%) 23.37043 427.8912 729.932 1038.776 868.7075 IWOFE ROAD OBIO/AKPO L.G.A, SOAKED CBR(%) 25.09881 398.4252 766.1417 1092.126 910.5512 CHOKOCHO ROAD ETCHE L.G.A , UNSOAKED CBR(%) 25.98056 384.9032 745.8065 1017.419 856.3871 CHOKOCHO ROAD ETCHE L.G.A , SOAKED CBR(%) 24.77137 403.6918 791.3323 1121.188 989.5666 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , 23.72635 421.4724 728.2209 1011.656 906.135 UNSOAKED CBR(%) NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , SOAKED 24.86772 402.1277 742.9787 1082.27 990.7801 CBR(%) OGBELE ROAD AHODA EAST L.G.A, UNSOAKED CBR(%) 27.23803 367.1338 604.4586 935.6688 749.6815 OGBELE ROAD AHODA EAST L.G.A, SOAKED CBR(%) 24.7216 404.5045 696.7568 1212.252 943.2432 UNCONFINED COMPRESSIVE STRENGTH (KPa) IWOFE ROAD OBIO/AKPO L.G.A Soil Unconfined 56.3141 177.5754 326.6932 384.7467 670.461 Compressive Strength (kPa) CHOKOCHO ROAD ETCHE L.G.A Soil Unconfined 55.06993 181.5873 386.0317 556.1905 765.7143 Compressive Strength (kPa) NDONI ROAD OGBA/EGBEMA/NDONI L.G.A Soil 51.34951 194.7438 297.7879 439.5916 609.7561 Unconfined Compressive Strength (kPa) OGBELE ROAD AHODA EAST L.G.A Soil Unconfined 42.52551 235.153 346.7307 559.0882 737.8524 Compressive Strength (kPa)

Clay + IGF + Cement IWOFE ROAD OBIO/AKPO L.G.A 2.50 , MDD(kN/m3) 2.00

1.50 CHOKOCHO ROAD ETCHE L.G.A , MDD(kN/m3) 1.00

0.50 NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , MDD(kN/m3) 0.00 Soil MDD(kN/m3) MDD(kN/m3) Soil

OGBELE ROAD AHODA EAST L.G.A , MDD(kN/m3) Unstabilized/ Stabilized Subgrade

Figure 3.1: Maximum Dry Density of Subgrade Stabilization Test of Clay Soil from Iwofe, Chokocho, Ndoni and Ogbele Roads Ndoni Local Government Areas of Rivers State with IGF + Cement at Different Percentages and Combinations

Clay + IGF + Cement IWOFE ROAD OBIO/AKPO 18.00 L.G.A, OMC (%) 17.50 17.00 16.50 CHOKOCHO ROAD ETCHE L.G.A , OMC (%) 16.00 15.50 15.00 NDONI ROAD 14.50 OGBA/EGBEMA/NDONI L.G.A 14.00 , OMC (%) Subgrade Soil OMC (%) Unstabilized / Stabilized / Stabilized Unstabilized

OGBELE ROAD AHODA EAST L.G.A, OMC (%)

Figure 3.2: Optimum Moisture Content of Subgrade Stabilization Test of Clay Soil from Iwofe, Chokocho, Ndoni and Ogbele Roads Ndoni Local Government Areas of Rivers State with IGF + Cement at Different Percentages and Combinations

IWOFE ROAD OBIO/AKPO L.G.A, LL(%) Clay + IGF + Cement IWOFE ROAD OBIO/AKPO L.G.A, PL(%) 80.00 70.00 IWOFE ROAD OBIO/AKPO L.G.A, IP(%) 60.00 CHOKOCHO ROAD ETCHE L.G.A , LL(%) 50.00 CHOKOCHO ROAD ETCHE L.G.A , PL(%)

40.00 CHOKOCHO ROAD ETCHE L.G.A , IP(%)

30.00 NDONI ROAD OGBA/EGBEMA/NDONI 20.00 L.G.A , LL(%) NDONI ROAD OGBA/EGBEMA/NDONI L.G.A , PL(%) Consistency (%) Consistency 10.00 NDONI ROAD OGBA/EGBEMA/NDONI 0.00 L.G.A , IP(%) OGBELE ROAD AHODA EAST L.G.A, LL(%) OGBELE ROAD AHODA EAST

Unstabilized / Stabilized Subgrade Soil Subgrade Stabilized / Unstabilized L.G.A, PL(%) OGBELE ROAD AHODA EAST L.G.A, IP(%)

Figure 3.3: Consistency Limits of Subgrade Stabilization Test of Clay Soil from from Iwofe, Chokocho, Ndoni and Ogbele Roads Ndoni Local Government Areas of Rivers State with IGF + Cement at Different Percentages and Combination

Clay + IGF + Cement IWOFE ROAD OBIO/AKPO L.G.A, UNSOAKED CBR(%) 90.00 IWOFE ROAD OBIO/AKPO L.G.A, SOAKED 80.00 CBR(%) 70.00

CBR(%) CHOKOCHO ROAD ETCHE L.G.A 60.00 , UNSOAKED CBR(%) 50.00 CHOKOCHO ROAD ETCHE L.G.A Soaked 40.00 , SOAKED CBR(%) 30.00 NDONI ROAD OGBA/EGBEMA/NDONI 20.00 L.G.A , UNSOAKED CBR(%) 10.00 NDONI ROAD OGBA/EGBEMA/NDONI 0.00 L.G.A , SOAKED CBR(%) OGBELE ROAD AHODA EAST L.G.A, UNSOAKED CBR(%) Soil Unsoaked and and Unsoaked Soil Unstabilized / Stabilized Subgrade Subgrade / Stabilized Unstabilized OGBELE ROAD AHODA EAST L.G.A, SOAKED CBR(%)

Figure 3.4: California Bearing Ratio of Subgrade Stabilization Test of Clay Soil from from Iwofe, Chokocho, Ndoni and Ogbele Roads Ndoni Local Government Areas of Rivers State with IGF + Cement at Different Percentages and Combinations

IWOFE ROAD OBIO/AKPO L.G.A Clay + IGF + Cement Soil Unconfined Compressive 700.00 Strength (kPa) 600.00 500.00 CHOKOCHO ROAD ETCHE L.G.A 400.00 Soil Unconfined Compressive 300.00 Strength (kPa) 200.00 100.00 NDONI ROAD 0.00 OGBA/EGBEMA/NDONI L.G.A Soil Unconfined Compressive Strength (kPa) OGBELE ROAD AHODA EAST L.G.A Soil Unconfined Compressive

Unstabilized / Stabilized / Stabilized Unstabilized Strength (kPa) Subgrade Soil Unconfined Soil Unconfined Subgrade Compressive Strength (kPa)

Figure 3.5: Unconfined Compressive Strength (UCS) of Subgrade Stabilization Test of Clay Soil from from Iwofe, Chokocho, Ndoni and Ogbele Roads Ndoni Local Government Areas of Rivers State with IGF + Cement at Different Percentages and Combination

4.0 Conclusions

The following conclusions were made from the experimental research results. i. The soils are classified as A – 7 – 6 /CH on the AASHTO classification schemes / Unified Soil Classification System as shown in table 3.1 ii. The soils are dark grey in color (from wet to dry states) with plastic index of 31.10%, 24.55%, 31.05%, and 32.17% respectively for Iwofe, Chokocho, Ndoni, and Ogbele Town Roads. iii. The soils has unsoaked CBR values of 7.35%, 7.75%, 8.15%, and 7.85% and soaked CBR values of 6.35%, 6.23%, 7.05% and 5.55% iv. Unconfined compressive strength (UCS) values of 87.85kPa, 78.75kPa, 105.75kPa , and 85.35kPa v. Verifiable results of un-stabilized and stabilized results showed tremendously increased of compaction parameters of MDD and OMC to varying percentages. vi. Comparably, results indicated increased in CBR altered soils with optimum mixed percentage ratios of 0.7% to soils. Stabilized clay soils increased in CBR values with increase in additives percentages to optimum mix ration 0.75% + 7.5%. Dropped in were noticed beyond optimum mix. vii. Results indicated increased in UCS with ratio increase to corresponding soils percentages. viii. Results indicated reduction in plastic index to increase in corresponding percentage ratios.

REFERENCES Akobo, I. Z. S., Priscilla N. I., and Charles, K., (2018). Comparative Strength Evaluation of Cementious Stabilizing Agents Blended with Pulverized Bagasse Fibre for Stabilization of Expansive Lateritic Soils. Global Scientific Journal, 6(12):239-255 Allam, M. M. and Sridharan, A. (1981). Effect of Repeated Wetting and Drying on Shear Strength. Journalof Geotechnical Engineering, ASCE, 107(4):421–438 Amakiri – Whyte, B., Nwikina, B. B., Charles, K., (2018). Expansive Soils Volumetric Control Using Composite Stabilizers. International Journal of Scientific & Engineering Research, 9(12): 1075 - 1091 Barisua, E. N., Charles, K., Ode, T., (2018). Comparative Strength Evaluation of Cementious Stabilizing Agents Blended with Pulverized Bagasse Fibre for Stabilization of Expansive Lateritic Soils. Global Scientific Journal, 6(12):220-238

Charles, K., Tamunokuro, O. A., Terence, T. T. W. (2018). Comparative Evaluation of Effectiveness of Cement/Lime and Costus Afer bagasse Fiber Stabilization of Expansive Soil. Global Scientific Journal, 6(5):97-110 Charles, K., Terence, T.T.W., Gbinu, S. K.(2018). Effect of Composite Materials on Geotechnical Characteristics of Expansive Soil Stabilization using Costus Afer and Cement. Journal of Scientific and Engineering Research, 5(5):603-613 Charles, K., Amakiri – Whyte, B., Terence, T. T. W. (2018). Stabilization of Black Cotton Clayey Soils with Cementitious Stabilizing Agents Blended with Waste Agricultural Products. Journal of Scientific and Engineering Research, 5(12):227-238 Charles, K.., Nwikina, B. B., Terence, T. T. W., (2018). Potential of Cement, Lime –Costaceae Lacerus Bagasse Fibre in Lateritic Soils Swell –Shrink Control and Strength Variance Determinations. Global Scientific Journal, 6(12):273-290 FMW (Federal Ministry of Works) 1997.General Specifications (Roads and Bridges), Vol II, Federal Ministry of Works and Housing, Lagos, Nigeria Nwikina, B. B., Charles, K.., Amakiri – Whyte. B., (2018). Modification of Expansive Lateritic Soils of Highway Subgrade with Blended Composite Materials and Performance Characteristics. Global Scientific Journal, 6(12):256-272 Ode, T., Charles, K.., Barisua, E. N., (2018). Strength Variance Evaluation of Cement / Lime with Irvinga Gabonesis Fibre Stabilized Black Cotton Soil. International Journal of Scientific & Engineering Research, 9(12): 1058 – 1074. Ola, S. A. (1974). Need for estimated cement requirements for stabilising lateritic soils. Journal of Transportation Engineering, ASCE, 100(2):379–388.

Omotosho, P. O. (1993). Multi-Cyclic Influence on Standard Laboratory Compaction of Residual Soils, Engineering Geology. 36, 109–115.

Omotosho, P .O. and Akinmusuru, J .O. (1992). Behaviour of Soils (Lateritic) Subjected to Multi- Cyclic Compaction. Engineering Geology, 32, 53–58 Ramakrishna, A.N. and Pradeepkumar, A.V. (2006). Stabilization of Black Cotton Soil using Rice

Husk Ash and Cement, Proc. of National Conference, Civil Engineering meeting the challenges of Tomorrow, 215-220 Sabat, A. K. (2012). Effect of Polypropylene Fiber on Engineering Properties of Rice Husk Ash – Lime Stabilized Expansive Soil, Electronic Journal of Geotechnical Engineering, 17(E), 651-660 Sharma, R.S., Phanikumar, B. R. and Rao, B.V. (2008). Engineering Behavior of a Remolded Expansive Clay Blended with Lime, Calcium Chloride and Rice-Husk Ash. Journal of Materials in Civil Engineering, 20(8): 509-515. Terence, T. T. W., Charles, K., Amakiri – Whyte, B., (2018). Performance Characteristics of Cement, Lime - Pozzolanic Bagasse Fibre Ash Stabilized Expansive Lateritic Soils for Highway Pavement Materials. International Journal of Scientific & Engineering Research, 9(12): 1092 – 1109.