Consolidation settlement occurs when a saturated soil is subjected to an increase in overburden pressure that causes a volume change in the soil. When a lightweight material is used as a ground improvement, the stress is reduced as the soft soil is partially removed and replaced by the lightweight material. In addition, the improved ground with lightweight material has a potential to uplift due to the buoyancy of lightweight material. The uplift force reduces the stress imposed on the underlying soil as it acts in the upward direction, thus further reducing the consolidation settlement. This study is executed to produce an alternative equation for consolidation settlement incorporating the buoyancy effect for lightweight polyurethane (PU) foam as a ground improvement method. A Rowe Cell consolidation laboratory test was conducted on untreated marine clay soil as well as on improved marine clay with different thicknesses of lightweight PU foam. Validation of the laboratory test results was done by finite element analysis, PLAXIS 2D. The thickness of PU foam governs the buoyancy and the hydrostatic pressure of water displaced by PU foam, which is incorporated in the alternative equation.  The alternative consolidation settlement equation is applicable for ground improved with lightweight polyurethane foam and found to be more economical and practical as the buoyancy is taken into account in the equation. ABSTRAK: Mendapan pengukuhan berlaku apabila tanah tepu mengalami peningkatan tekanan beban yang menyebabkan perubahan isipadu tanah. Apabila bahan ringan digunakan sebagai penambahbaikan tanah, tekanan akan berkurang kerana sebahagian tanah lembut dikeluarkan dan diganti dengan bahan ringan. Selain itu, tanah yang diperbaiki dengan bahan ringan berpotensi untuk terangkat ke atas keranan daya apung bahan ringan. Daya angkat bahan ringan mengurangkan tekanan yang dikenakan ke atas tanah kerana daya bertindak ke arah atas, dan seterusnya megurangkan mendapan pengukuhan. Kajian ini dijalankan untuk menghasilkan persamaan alternatif bagi mendapan pengukuhan dan digabungkan dengan kesan daya apung untuk busa poliuretena ringan (PU) sebagai kaedah penambahbaikan tanah. Ujian makmal mendapan pengukuhan menggunakan peralatan Rowe Cell dilakukan pada tanah liat marin yang asal serta yang diperbaiki dengan ketebalan busa PU ringan yang berbeza. Pengesahan hasil ujian makmal dilakukan dengan analisis elemen terhingga, PLAXIS 2D. Ketebalan busa PU mempengaruhi daya apung dan tekanan hidrostatik bagi kedalaman air yang disesarkan oleh busa PU dan digabungkan dalam persamaan alternatif. Persamaan alternatif mendapan pengukuhan tersebut boleh digunapakai untuk pembaikan tanah menggunakan bahan ringan busa poliuretena dan didapati menjimatkan kos dan praktikal kerana keapungan diambilkira didalam persamaan tersebut.

The waste generation of palm oil boiler ash has been one of its big problems as it is less used and deposited in landfills as a by-product. Geopolymer is a new green technology that has been intensively studied in concrete applications. However, few studies on geopolymers have been conducted in soil applications. Thus, this study investigated the influence of palm oil boiler ash-based geopolymer in laterite soil strength. Different percentages, 5, 10, 15, and 20% of geopolymer mixtures, were added to laterite soil. The process of producing a geopolymer binder was performed by sieving boiler ash (150 µm), then mixing with sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) as an alkaline activator at a ratio of 1:2. This material effectiveness was tested through compaction test using a standard proctor, unconfined compressive strength, and the scanning electron microscope (SEM). 15% of geopolymer in laterite soil indicated the best-mixed design with a maximum dry density of 2.23 Mg/m3 with a moisture content of 13.58%. The unconfined compressive strength test at curing times of zero, seven, and twenty-eight days on the LS-15.0 GPOBA sample, show a slightly increased strength of 47, 58, and 76 kPa, respectively. The SEM images proved that the geopolymer gel's development stabilized the soil structure from a loose structure to a denser soil structure. This study aims to investigate the influence of geopolymer in laterite soil. Boiler ash as an alternative material in geotechnical applications was studied to understand and develop new green alternative materials to sustain the environment from industrial waste and to enhance laterite soil properties. ABSTRAK: Abu kelapa sawit adalah salah satu sisa utama yang terhasil dari industri kelapa sawit tetapi penggunaannya kurang dimanfaatkan dan dibuang ke tempat pembuangan sampah. Teknologi hijau baru yang dikenali sebagai geopolimer telah dikaji secara intensif dengan kekuatan konkrit tetapi hanya sedikit kajian telah dibuat dalam penggunaan tanah. Tujuan kajian ini adalah bagi mengesan geopolimer berasaskan abu kelapa sawit terhadap kekuatan tanah laterit. Peratusan campuran geopolimer yang berbeza (0, 5, 10, 15 dan 20%) dicampur pada tanah laterit. Bagi menghasilkan geopolimer, saiz 150 ?m abu kelapa sawit disintesis dengan kombinasi bahan kimia natrium hidroksida (NaOH) dan natrium silikat (Na2SiO3) pada nisbah 1:2 bagi semua campuran sebagai pengaktif alkali. Ujian terhadap keberkesanan bahan adalah melalui proses ujian pemampatan menggunakan proktor standard, kekuatan pemampatan tidak terbatas, dan Pengimbas Mikroskop Elektron (SEM). Berdasarkan dapatan ujian pemadatan, 15% geopolimer di tanah laterit menunjukkan campuran terbaik dengan memberikan kepadatan pengeringan maksimum 2.23 Mg/m3 pada kelembapan 13.58%. Ujian kekuatan mampatan tidak terbatas pada masa pempolimeran sebanyak 0, 7 dan 28 hari diuji pada sampel LS-15.0GPOBA bagi menguji kekuatan campuran. Dapatan menunjukkan kekuatan geopolimer sedikit meningkat pada 47, 58 dan 76, masing-masing. Imej SEM membuktikan pengembangan gel geopolimer menstabilkan struktur tanah daripada struktur lopong kepada struktur tanah padat. Oleh itu, abu kelapa sawit berasaskan geopolimer dan tanah laterit berpotensi sebagai alternatif bagi merawat tanah dalam aplikasi geoteknik dan berpotensi mengurangkan kadar kebolehtelapan.

This paper reports the outcome of the laboratory investigation conducted on new clay liners modified with kaolinite combined with various content of lime-treated, various content of bentonite and admixture of kaolinite adding with 3% nano-kaolinite for composition. The 3% nano-kaolinite was chosen based on earlier finding by S.V.Netethu (2013). The various content of lime-treated and bentonite adopted are 2.0%, 5.0%, 7.5% and 10.0% by total weight of the kaolinite. Compaction tests was performed on the resulted modified clay liner samples to evaluate the best percentage that gives optimum moisture content (OMC) and maximum dry density (MDD) . The best percentage of each bentonite and lime-treated are chosen and be added into kaolinite and the physical properties of samples are tested and compared to the other two samples which are kaolinite only and kaolinite added with 3 % of nano-kaolinite. Nano-kaolinite was produced using a mill machine and the sized of nano-kaolinite (1nm-100nm) were examined under Scanning Electron Microscope (SEM) machine.The addition of 3% nano-kaolinite to the kaolinite gives the best compaction result compared to bentonite or lime-treated. The value of dry density is increased to give the reduction of air voids, thereby reducing the hydraulic conductivity by concept. Based on the compaction test value, it clearly observed that admixture of kaolinite adding with 3% nano-kaolinite gives the best results from the other samples due to required less water to achieve maximum dry density of 1.39 Mg/m3 and 27.34% of optimum moisture content resulted positive effect in soil properties.

Nano-clay is one of the innovation recently been studies as one of the enhancing materials to the soils. By adding a slight amount of nano-clay can improve some of behaviour such as hydraulic conductivity. Therefore, this research will investigate the performance of the hydraulic behaviour of different percentage of nano-clay in developing new soil liner design to be used in landfill. To complete the objectives, bentonite was pulverized by the process of high energy milling to obtain nano-bentonite. The milling sample is being analysed using Zeta Potential Analyzer and Field Emission Scanning Electron Microscope (FESEM). The laboratory studies were conducted by the determination geotechnical properties of the liquid limit, plastic limit, plasticity index shrinkage limit, particle density, compaction characteristic and also hydraulic conductivity value of raw bentonite mixed with 0%1%,2% and 3% of nano-bentonite. The laboratories result shows that the value of liquid limit, plastic limit, particle density and maximum dry density is increase in every addition of nano percentages meanwhile the value of plasticity index, optimum moisture content and hydraulic conductivity is decrease after adding nano-bentonite in the sample. The result shows the improvement of the soil by the geotechnical properties with addition of small amount of nano-bentonite.

Due to the spread of the COVID-19, many universities throughout the world are experiencing partial or complete disruptions to their academic programmes. As a result, more and more institutions are making the essential changes to their instruction in teaching and learning processes, including laboratory classes from face to face into a hybrid or online delivery format. Regardless of the actions done, lecturers must keep up their rigorous academic standards and offer a top-notch student as necessary for delivering the learning outcomes linked to courses especially laboratory courses that normally being conducted face to face in the laboratory or workshop to online or open distance learning (ODL). This transformation will present a challenge to academicians across the higher education sector, forcing them to switch from normal class delivery to online instruction and various laboratory delivery strategies. Students as a result will not receiving direct instruction from lecturers, and they have limited or no access at all to laboratory resources that necessary for delivering the learning outcomes linked to each programme courses. This paper reviews approaches taken by Faculty of Civil Engineering, UiTM and lecturers to deliver teaching and laboratory practices remotely, in consideration of the COVID-19 pandemic. This review is primarily focused on implementation on teaching delivery and laboratory assessments given to Civil Engineering Diploma Students in Soil Engineering Laboratory Course during COVID outbreaks. The findings of this study may be used to improve online engineering education during and after pandemics in other institutions or courses with a similar demographic.