Physiochemical characterization of lateritic bauxite mining soil

Physiochemical characteristics play a significant role in evaluating the engineering behaviour of soil material and its suitability for foundation. Investigation upon the physical and chemical characteristics of lateritic bauxite soils were done on samples collected from three ex-mining bauxite sites (Bukit Goh, Semambu and Indera Mahkota) in Kuantan District, Pahang, Malaysia. The presence of chemical element was evaluated based on the elemental mineral composition content identified through X-Ray Fluorescence (XRF). The results revealed that Semambu lateritic bauxite soil has the highest content of alumina (Al2O3), 25.54%. The alumina content enrichment is one of the effects from the laterization of bauxite process. In addition, the physical testing included are moisture content, specific gravity and Atterberg Limit. Further investigation on the physical properties of the soil has found that Semambu has the highest MC, 33.27%, but at the same time PI is less than 12%. This is as a key indicator that lateritic bauxite is prone to surface erosion and unsuitable for construction purposes in its natural condition. The risk of the surface erosion and settlement of the ground causes it requires stabilizer that can rapid the curing time. Additionally, the high moisture content is likely to have higher chance to experience liquefaction and causes foundation problem to future infrastructures that may be built in the studied area

Physiochemical characterization of lateritic bauxite mining soil

Physiochemical characteristics play a significant role in evaluating the engineering behaviour of soil material and its suitability for foundation. Investigation upon the physical and chemical characteristics of lateritic bauxite soils were done on samples collected from three exmining bauxite sites (Bukit Goh, Semambu and Indera Mahkota) in Kuantan District, Pahang, Malaysia. The presence of chemical element was evaluated based on the elemental mineral composition content identified through X-Ray Fluorescence (XRF). The results revealed that Semambu lateritic bauxite soil has the highest content of alumina (Al2O3), 25.54%. The alumina content enrichment is one of the effects from the laterization of bauxite process. In addition, the physical testing included are moisture content, specific gravity and Atterberg Limit. Further investigation on the physical properties of the soil has found that Semambu has the highest MC, 33.27%, but at the same time PI is less than 12%. This is as a key indicator that lateritic bauxite is prone to surface erosion and unsuitable for construction purposes in its natural condition. The risk of the surface erosion and settlement of the ground causes it requires stabilizer that can rapid the curing time. Additionally, the high moisture content is likely to have higher chance to experience liquefaction and causes foundation problem to future infrastructures that may be built in the studied area

Characterization of industrial by-products as asphalt paving material

Most of the recent research is focusing on the utilization of industrial by-products in road construction. The intention is not only to mitigate the problem of waste being dumped to the landfills but to encourage their use as construction material without compromising quality and performance of the road. Steel slag and bottom ash are the industrial by-products generated in large quantity by industry. This study investigates the characteristics of steel slag and bottom ash to be utilized as aggregate in asphalt pavement. Both materials were characterized in terms of physical, chemical and morphological characteristics compared to the conventional granite aggregate. The results revealed that both materials have much potential to be used as aggregate in asphalt mix. The bottom ash was observed weaker in terms of strength, but the steel slag was found much stronger than the granite. The morphological structure of bottom ash and steel slag disclosed that these are made up of porous and rough-edged granular particles with slightly higher water absorption

Accidents preventive practice for high-rise construction

The demand of high-rise projects continues to grow due to the reducing of usable land area in Klang Valley, Malaysia.The rapidly development of high-rise projects has leaded to the rise of fatalities and accidents.An accident that happened in a construction site can cause serious physical injury.The accidents such as people falling from height and struck by falling object were the most frequent accidents happened in Malaysian construction industry.The continuous growth of high-rise buildings indicates that there is a need of an effective safety and health management. Hence, this research aims to identify the causes of accidents and the ways to prevent accidents that occur at high-rise building construction site.Qualitative method was employed in this research. Interview surveying with safety officers who are involved in highrise building project in Kuala Lumpur were conducted in this research. Accidents were caused by man-made factors, environment factors or machinery factors.The accidents prevention methods were provide sufficient Personal Protective Equipment (PPE), have a good housekeeping, execute safety inspection, provide safety training and execute accidents investigation.In the meanwhile, interviewees have suggested the new prevention methods that were develop a proper site layout planning and de-merit and merit system among subcontractors, suppliers and even employees regarding safety at workplace matters.This research helps in explaining the causes of accidents and identifying area where prevention action should be implemented, so that workers and top management will increase awareness in preventing site accidents

Rock bearing resistance of bored piles socketed into rock

In view of the large movement required to mobilise the base resistance of bored piles and difficulty in base cleaning, the end bearing resistance often ignored in current design practice that will result in excessive rock socket length. Many attempts have been made to correlate the end bearing resistance with the uniaxial compressive strength of intact rock and the RQD but it is uncertain how applicable they are to rock type in Malaysia. This paper attempts to review the applicability of the formulas from previous studies to rock type in Malaysia. A program of field tests for 13 bored piles with diameter varying from 1000 mm to 1500 mm constructed in granite was conducted to measure the axial response of bored piles, tested using static load test and high strain load dynamic test to verify its integrity and performance. The results were evaluated and compared to the predicted rock bearing resistance. Based on the result obtained, the method by AASHTO gives the best prediction of rock bearing resistance for granite in Malaysia. However the relationship between compressive strength and rock discontinuities with the rock bearing resistance showed scattered results

Improving the bearing capacity of marine clay using polyurethane columns

Problematic soil such as marine clay causes structures or pavement to crack and collapse as marine clay possesses low bearing capacity. Therefore, ground improvement is usually conducted to improve the bearing capacity. Since the use of cement for strengthening weak soil is not environmental-friendly, the aim of this study is to improve the bearing capacity of marine clay using polyurethane (PU) columns. The properties of the marine clay collected from Batu Pahat determined were particle size distribution, Atterberg's limits, specific gravity, and compressibility were determined. A series of small-scale physical modelling was conducted with a tank's size of 500 mm x 500 mm x 200 mm. The 1:1 ratio of poly and isocyanate was injected into the cored hole for the column formation with the area improvement ratio was set as 12.6%. The loading process was conducted 1 day after column installation. Double tangent method from the stress-displacement curve was employed to determine the ultimate bearing capacity of the marine clay. The ultimate bearing capacity of the untreated marine clay was 50 kPa. In addition, the results showed that the ultimate bearing capacity of the marine clay increased with the length of the PU columns. A maximum improvement ratio of 220% was achieved for the end bearing PU columns. Comparing the improvement ratio with the published data showed that PU columns had a better performance than soil cement or deep mixing cement columns due to its lightweight and high strength. Therefore, the replacement of cement with PU is workable and sustainable in ground improvement method

Geochemistry characterisation of marine clay

In evaluating a suitable type of stabiliser, investigating geochemical characteristics is important for improving the properties of soil. This paper assessed the geochemistry of marine clay samples collected from Batu Pahat, Johor, Malaysia. The parameters investigated were pH, loss on ignition (LOI) and the quantities of sulphate, chloride, nitrate and carbonate ions. The results revealed that the clay was an acidic soil with pH of 3.25 and containing 8% of organic matter. The clay also contained 6,071 mg/l, 281 mg/l and 22 mg/l of sulphate, chloride and nitrate ions, respectively. Sulphate and chloride ions from acid rain and decomposed organic matters are the leading causes of acidity found in clay. Further investigation of the physical properties of the soil further indicated that it belonged to a group of clay having high plasticity (CH) and is unsuitable for construction purposes in its natural condition. The concentration of sulphate ions in the clay sample also advocated that the soil is not suitable to be stabilised using cement or lime due to the risk of the formation of a complex compound of calcium sulphoaluminate hydrate (ettringite). Additionally, the sulphate in the marine clay is likely to attack the concrete of the foundation of future infrastructures that may be built in the study area

Compaction characteristics of lime-treated tropical soil

Like soils of other regions in the world, some tropical soils are also associated with problems of low strength. To improve engineering characteristics of soils, several methods have been employed worldwide which are categorized as mechanical, chemical, thermal and electrical. The aim of this research is to compare the compaction characteristics of untreated and lime-treated soils. Soil samples obtained from three different points within a project site in Klang, Selangor were utilized in this study. Each sample was subjected to Eades and Grimm's test in accordance with ASTM D6276-99a to determine the appropriate lime dosage for soil stabilization. The required lime dosage was found between 1.3% and 3.4%. Then each untreated soil and soil sample mixed with 5% lime, higher than that obtained from Eades and Grimm's tests were compacted in accordance with BS 1377:1990. Generally, each soil sample achieved lower values of maximum dry density after treated with 5% lime than those of the untreated soils. Such observations were in good agreement with those obtained by previous researchers working on lime-treated soils. Nonetheless, the optimum moisture content of the lime-treated sample from Points 1 was slightly higher than that of the untreated sample. This finding was different from those obtained by previous researchers. Such contradicting observation might be due to the type and quantity of mineralogical contents of the soils studied

Effect of voids in kaolin stabilised by ground granulated blast furnaces slag mixtures

Kaolin is known as problematic soil which has a low strength that needs to improve before construction. Chemical stabilization with cement is used widely to stabilize different clay types; however, using it comes with disadvantages associated with carbon dioxide emission and sustainability issues. As an alternative to cement, Ground Granulated Furnaces Blast Slag (GGBS) has been applied to stabilise kaolin. The increment in the strength is due to the formation of new products that fill the soil voids. The formation of those new products is verified using Field Emission Scanning Electron Microscopy (FESEM). However, the changes in pore space cannot be quantified using FESEM. Thus, this study uses Image J to calculate voids area detected by (FESEM) for different kaolin-GGBS mixtures with different content of GGBS cured for different curing period. The book-like structure for the raw kaolin have changed slightly when mixed with GGBS. This is due to the formation of hydrate gels as a result of the pozzolanic reaction. The results from image J indicates that the void decreases as the content of GGBS increases as well as the curing period

Strength behaviour of kaolin treated by demolished concrete materials

Kaolin has claynite structure in nature, presenting several properties which may justify in many engineering and industrial applications. However, this type of soil is categorised as problematic soil because the presence of claynite properties eventually resulting the kaolin to have low shear strength and high compressibility as other clay soil. Due to that weakness, kaolinite does not meet the requirements necessary for any construction purposes particularly at the preliminary stage. Hence, to overcome this issue, soil stabilisation process is needed prior any construction works. The aim of this study is to determine the strength characteristics of stabilised soft clay soil (Kaolin S300) with demolished concrete materials (DCM). The selection of DCM as the stabilizer for the purpose reutilisation of waste materials that currently has been a great concern for the environmental sustainability. The percentages of DCM content used were 5%,10%,15%20%,25%,30% with varying curing time of 7days, 14 days and 28 days, respectively. Based on the result it was reported that, the unconfined compressive strength (UCS) test shows that the highest strength value obtained of 595.6 kPa kaolin treated with 30% DCM at 28 curing days. It is equivalent to 92% increment from the untreated kaolin sample at 0 days. However, the optimum amount of DCM which provides significant strength improvement was found when more than 20% of DCM is presented after 14 curing days. Hence, it shows the possible usage of DCM as waste material to effectively stabilize kaolin at specific amounts sufficiently