Faizal Pakir

Stabilization of Marine Clay by Biomass Silica (Non-Traditional) Stabilizers

The presence of marine clay in Iskandar Malaysia Region, Nusajaya had caused expensive solutions in the construction of structures and roads. Alternatively, soil treatment is suggested to increase the strength of the unsuitable material to meet the constructions requirement for foundation and also to achieve the specifications for development work. In this study, a series of laboratory test has been conducted to determine the potential of Biomass Silica (BS), one of the commercial brands namely “SH-85” to stabilize marine clay to form the basis of a strong, reliable land for construction of roads and building. Testing program involves obtaining specimens of marine clays from various locations at Iskandar Malaysia Region, followed by laboratory tests to determine the Atterberg limits and Unconfined Compressive Strength (UCS) for treated and untreated of marine clay soils. The proportions of BS added were 3, 6, 9, 12 and 15% and tested at 0, 3, 7 and 28 days curing periods. The results shows that the Plasticity Index (PI) was reduce with increment of BS content. While, an addition of BS content increase in strength treated soils 60 times more than untreated soils, which is gain in early 7 curing days period. This finding indicates the BS is a suitable stabilizer for the marine clay to become strong foundation for construction of road and building.

PERFORMANCE OF LIME-TREATED MARINE CLAY ON STRENGTH AND COMPRESSIBILITY CHRACTERISTICS

The presence of marine clay in Iskandar Malaysia Region, Nusajaya has caused expensive solutions in the construction of structures and roads. Alternatively, soil treatment is suggested to increase the strength of the unsuitable material to meet the constructions requirement for foundation and also to achieve the specifications for development work. In this study, a series of laboratory test has been conducted to determine the potential of lime to stabilize marine clay to form the basis of a strong, reliable land for construction of roads and building. Testing program involves obtaining specimens of marine clays from various locations at Iskandar Malaysia Region, followed by laboratory tests to determine the physical and engineering properties with and without the addition of lime. The proportions of hydrated lime added are 3%, 6% and 9% to the untreated marine clay and tested at 7 and 28 days curing periods. Results show an increase in strength with increasing lime content. In addition, strength also increases significantly as early as 7 curing days and continues for 28 curing days. In agreement with the strength tests, compression characteristics improved with increasing lime content and as time prolonged. Hence, lime is successful and considered effective to improve the strength and compressibility behavior of Marine clay.

Effect of Humic Acid on Geochemistry Properties of Kaolin

Organic soil is always known as problematic soil because of its engineering properties are inferior from other soft soils and/or because its behaviour may deviate from traditional rules of soil behaviour which makes it difficult to predict and design. Considerable research has been carried out over the years on organic soils, particularly peat soil which consists of various components of organic matter but the effect of particular organic matter is less reported. Hence, this study is carried out to determine the effect of humic acid (a kind of humified organic matter) on kaolin (which is widely studied). This paper addresses the influence of humic acid (30% and 50% of dry mass) on kaolins geochemistry properties namely Atterberg limits, compaction, specific gravity and Loss on Ignition (LOI). The findings of the study showed that the contents of humic acid had altered the behaviour of kaolin. The loss on ignition increased linearly with the increment of humic acid. However, the specific gravity, maximum dry density and Atterberg limits decreased with addition of humic acid. Atterberg limits decreased as the humic acid increased is believed to be due to the nature of humic acid which precipitated under acidic environment.

Effect of fines content on critical state parameters of sand matrix soils

Natural sand does always contain significant amounts of fine particles, known as sand matrix soils. The development of critical state for sand and clay are both well established. However, limited researchers focused on the sand matrix soils. This paper discusses the effect of fines content on the critical state parameters of sand matrix soils. Two types of plastic fines with different plasticity (kaolin and bentonite) were mixed into poorly graded Johor clean sand at different percentages to form the sand matrix soils. The critical state was obtained from the strain controlled triaxial compression test. All tested soils had been isotropically consolidated to four different effective confining pressures and sheared under consolidated undrained condition until the critical state was ascertained. The critical state line was plotted for each sand matrix soils on space and compression spaces. Based on linear regression analysis, the critical state parameters, M, λ and Γ were obtained and the ranges are from 0.807 to 1.102, 0.062 to 0.160 and 1.732 to 2.431, respectively. The trend of the critical state lines of sand matrix soils in both stress and compression space coincides with the concept of threshold fines content. The threshold fines content identified for sand-kaolin mixtures is 25 % kaolin while it is 20 % bentonite for sand-bentonite mixtures.

Plasticity Behaviour of Sand Matrix Soils

Natural sand does always contain significant amounts of fine particles, but previous study always assumes that the typical engineering characteristic of clean sand was remarkably representing as to all types of sand matrix soils. Studies reported that additional of plastic fines could either impose additional or reduce the liquefaction resistance of sand matrix soils. Therefore, the aim of this paper is to examine the plasticity behaviour of sand matrix soils through experimental study. The Atterberg Limit test was carried out on plastic fines mixtures and sand matrix soils. Results show that the plasticity behaviour is depending on the type of presenting plastic fines. The absorption of clay mineral is the key element to in manipulating the plasticity behaviour of plastic fines. It can be concluded that the absorption of montmorillonite is better compare to kaolinite.

Analysis of Lightweight Concrete “Cakar Ayam” Foundation for Road Construction using Plaxis 3D Foundation Software

Road settlement often occurs because that soil cannot accommodate the load capacity. Therefore, the study to analysis of lightweight concrete “cakar ayam” foundation was conducted. The idea of “cakar Ayam” concept was introduced by Prof. Dr. Ir. Sediyatmo. Objective of these studies was achieved which is to determine the settlement value of lightweight concrete “Cakar Ayam” foundation design on soft clay, sand, clayey silt under the different loads. Hence, the effectiveness of lightweight concrete “cakar ayam” foundation on that soil, have been able to determined according the settlement value was obtained. Implementation of research was doing using Plaxis 3D foundation software. The foundation design was various according to the several of the column length. The slab thickness, spacing between column, foundation and column size was fixed. Soil parameters to analyse lightweight concrete “cakar ayam” foundation, was obtained from previous studies and Research Center of Soft Soil, Universiti Tun Hussien Onn Malaysia, (RECESS, UTHM). Each design was tested by different loads to get the settlement value. From the results show, the settlements value was obtained show concept of “cakar ayam” foundation, not effective to be implement on soft clay. The settlement value was over 25 mm, when the load 20 kN/m2 was applied on the foundation, to all length of column on soft clay. However, the settlement value was lower than 25 mm, when the load 40 kN/m2 was applied on the foundation, to all length of column on sand and clayey silt. From all the settlement value, it could be seen that clayey silt result was more effective than sand. The settlement value also was decrease when the length of pile was increase. In conclusion, the objective of the study was achieved.