Effect of cement additive and curing period on some engineering properties of treated peat soil

Peat soil is characterized by its high content of decomposed organic matter. Majority of areas occupied by peatland have been developed for agriculture sectors such as pineapple cultivation and oil palm. Due to its geotechnical drawback characteristics such as highly compressibility and low shear strength, peat soil is classified as problematic soils and unstable for engineering structures. Lack of suitable and expensive price of lands, peatland will be an alternative option for future development. Prior to construction works, stabilization of peat soil should be performed to enhance its engineering characteristics. This paper presents the effect of cement and curing period on engineering properties of the cement-treated peat soil. Some engineering variables were examined including the compaction behaviour, permeability and unconfined compressive strength (UCS). The Atterberg limit test was also carried out to examine the influence of cement addition on peat soil. The cement-treated peat soils were prepared by adding varying amount of ordinary Portland cement (OPC) ranging between 0% and 40% of dry weight of peat soil. In order to examine the effect of curing, the treated samples were dried at room temperature for three and seven days while for UCS tests samples were extended to 28 days prior to testings. The results showed that the liquid limit of treated soil decreased with the increase of cement content. Maximum dry density (MDD) increased while optimum moisture content (OMC) dropped with the increase in cement content. Permeability of treated soil decreased from 6.2×10-4 to 2.4×10-4 ms-1 as cement content increase from 0% to 40%. In contrast, the UCS tests indicated an increase in uncompressive strength with the increase in cement contents and curing period. The liquid limit and permeability were also altered as curing periods were extended from three to seven days. This study concluded that geotechnical properties of peat soil can be stabilized using ordinary cement and by modification of the curing periods

Potential of Normalized Difference Vegetation Index for Mapping of Soft Clay Area in Paddy Fields of Kedah, Malaysia

Mapping of soft clay area in paddy fields uses remote sensing and GIS technique is the fastest way to obtain an accurate location of soft clay in a large scale area. It can be an alternative way to change conventional method like in-situ observation that is expensive and labor intensive. Therefore, this study aimed to investigate the normalized difference vegetation index (NDVI) to map soft clay area in paddy fields Kedah, Malaysia. To analyze soft clay area comprehensively, the study was carried out in three different periods; before paddy planting, after paddy planting and harvest. Ground-truth data of soft clay area was collected from study area during fieldwork activity and compared with NDVI values that produced from Landsat 8 image. Result of study showed NDVI map in period of before paddy planting could be a good indicator for mapping soft clay area because it gave a higher accuracy value than the other periods, with overall accuracy (85%) and kappa coefficient (0,84). Total area of soft clay from the highest value was showed in period of before paddy planting (1.856,97 ha), followed by after paddy planting (656,73 ha) and harvest (401,85 ha) periods, respectively

Soil erosion assessment in Tasik Chini Catchment using remote sensing and gis techniques

Over many years, forested land transformation into urban, agriculture and mining areas within Tasik Chini Catchment become more intense. These activities have negatively affected the catchment through soil erosion and increased the amount of sediments that deposited into the lake. Hence, the present study aimed to estimate soil erosion risk within Tasik Chini Catchment integrating the Revised Universal Soil Loss Equation (RUSLE) model and remotely sensed geospatial data. The multispectral imagery from LANDSAT 8 was used to provide up to date information on land cover within the catchment. The result shows the majority of Tasik Chini Catchment is classified at very low class ( 150 ton ha−1 yr−1) with total area of 120.04 ha (2.30%). Tasik Chini Catchment is very susceptible to soil erosion especially on northwest and southeast regions, where the main sources of soil loss come from the agricultural, new settlements and mining activities. To conclude, the estimation of soil erosion model using remotely sensed data can be used to build sustainable development strategy within Tasik Chini Catchment in the future

Agricultural Land Evaluation Using GIS-Based Matching Method in Highland Areas for Oil Palm Cultivation

Oil palm (Elaeis guineensis) is one of the commodity crops and is mostly found in tropical lands. This study aimed to analyze the current and potential land suitability for oil palm using the geographic information system (GIS) technique. The study was conducted in the Ranau District, Sabah State, Malaysia. Field activity was carried out to collect soil samples and land information in the study area. Land suitability was then assessed using the matching method and GIS software was employed to produce a land suitability map for oil palm. The results indicated that the current land suitability classes in the study area were highly suitable (S1) with a total area of 99,118 ha (27.4%); moderately suitable (S2) with 110,108 ha (30.4%); marginally suitable (S3) with 109,533 ha (30.2%); currently not suitable (N1) with 2,728 ha (0.7%) and permanently not suitable (N2) with 40,693 ha (11.3%). Meanwhile, the potential land suitability classes showed 198,206 ha (54.7%) for S1; 123,281 ha (34%) for S2 and 40,693 ha (11.3%) for N2. Suitable areas that could be planted with oil palm included the gently sloping flank and the low gradient slope margin. Availability of nutrients and work capability were the dominant limiting factors in the study area. The outputs of this study recommend that the Ranau District has the potential for oil palm although it still needs land improvements for sustainable oil palm cultivation

Hydrological change effects on Sungai Langat Water quality

This study attempts to assess the impact of various types of land use along Sungai Langat and describes hydrological change and water quality variation along this river. This study also determines water quality of Sungai Langat based on low flow dry period Q100,7 using the application of QUAL2K. Dissolved oxygen (DO), pH, temperature and conductivity were measured in situ. Biochemical oxygen demand (BOD5), ammonia nitrogen (NH3-N) and total suspended solid (TSS) were analysed according to the standard methods (APHA). Water quality data was referred to National Water Quality Standards for Malaysia (NWQS) proposed by Malaysian Department of Environment (DOE) to estimate Sungai Langat water quality status. Four important water quality parameters namely DO, BOD5, NH3-N and TSS were simulated with QUAL2K version 2.07 for 83.67 km. As regard to individual parameter, DO classified this river into class III, BOD5 in Class II, NH3-N in Class IV and TSS in Class I. Based on QUAL2K simulation for low flow scenario, the results clearly demonstrates a gradually reduction of DO and BOD5 whereas NH3-N and TSS display opposite. Only NH3-N was found significantly increase which cause low water quality class towards the downstream. Three parameters namely DO, BOD5 and NH3-N show effects of industrial which approximately located at the middle of river stretch. The TSS was contributed to the river system at the upstream and downstream of the river stretch which most likely from sand mining activity which located at Sungai Long, Cheras (near R5) and Sungai Semenyih (R11)

Kesan suhu dan bahan tambah abu terbang terhadap pencirian mekanik bata daripada sisa rawatan air mentah

Penggunaan semula sisa dalam pembangunan bata giat diusahakan dan beberapa pengubahsuaian dilakukan bagi menghasilkan produk bata yang berkualiti baik dan selamat. Suhu merupakan antara faktor yang mempengaruhi cirian mekanik bata. Oleh itu, objektif kajian ini adalah untuk melihat pengaruh suhu dan abu terbang (RAM) terhadap sifat mekanik bata yang dihasilkan daripada campuran sisa rawatan air mentah (RAM). Dua jenis sampel bata disediakan melibatkan bata 100% sisa RAM (RAM100) dan bata campuran 80% sisa RAM dan 20% AT (RAM80). Kedua-dua jenis sampel dikenakan suhu pembakaran berbeza (tanpa bakar, 500 °C, 700 °C) selama tiga jam. Ujian larutresap turut dilakukan bagi mengenal pasti kepekatan logam berat yang hadir dalam bata. Pencirian mekanik bagi penyusutan linear menunjukkan peningkatan dengan pertambahan suhu. Kehadiran sisa AT meningkatkan nilai penyusutan linear yang lebih tinggi berbanding bata berasaskan RAM (RAM100) apabila suhu meningkat daripada 350 kepada 700 °C. Nilai ketumpatan kedua-dua jenis bata turut menyusut dengan peningkatan suhu namun meningkat semula pada suhu yang lebih tinggi (700 °C). Kedua-dua jenis bata juga menunjukkan peningkatan penyerapan air dengan peningkatan suhu. Kehadiran AT turut mengurangkan nilai serapan air berbanding bata RAM100. Kekuatan mampatan bata meningkat dengan peningkatan suhu dan bata RAM100 menunjukkan corak peratus peningkatan yang ketara berbanding bata RAM80. Namun, daripada perspektif peratusan, kehadiran AT menunjukkan peratusan pertambahan kekuatan mampatan yang ketara berbanding bata RAM100. Daripada hasil ujian larutresap dan cirian mekanik yang dilakukan, sisa rawatan air dan abu terbang berpotensi digunakan sebagai bahan asas dalam pembangunan bata dan beberapa pengubahsuaian diperlukan bagi mencapai piawaian yang ditetapkan sebagai bahan binaan alternatif

Mechanical characteristics of developed brick from drinking water sludge under different firing temperatures and rice husk ash contents

There is a considerable interest in making alternative bricks using wastes. Firing temperature has been significantly improved the mechanical qualities of bricks. The aim of this study was to investigate into the impact of firing temperature and rice husk ash content on the mechanical properties of drinking water sludge bricks (DWS). Two types of bricks were produced; bricks made of 100% DWS (DWS100) and bricks with 80% DWS and 20% RHA (DWS80). These samples were subjected to different thermal variations of 300 °C and 700 °C for three hours. The unfired brick samples were also prepared for reference. The volume changes of the DWS100 bricks increased as the firing temperature climbed up to 500 °C, before dropped at 700 °C. A similar behaviour was also exhibited by DWS80 bricks, however it shrunk at earlier temperature of 500 °C. At 500 °C and 700 °C, the density of bricks decreased dramatically, with DWS80 bricks consistently being lesser than DWS100 bricks. The water absorption of DWS80 brick began to decrease at 500 °C, a lower temperature than that of DWS100, as the firing temperature climbed. RHA-added bricks (DWS80) were anticipated to absorb more water than DWS100 bricks, but this did not occur. This presumably induced by the constriction of clay mineral structure rather than organic matter removal at high temperature per se. The compressive strength increased with the increase in temperature. It can be inferred that RHA can decrease the compressive strength of RHA-added bricks, despite the fact that a higher fire temperature significantly increased their strength

Potential Of Vetiver Grass and Kim Chiam As Slope Stabilizer at Different Elevation In Good Agricultural Practices (MyGap) Area

The fast tempo of agriculture development and land use changes has resulted in a rapid depletion of most of the suitable land for agriculture in the country. This has caused the opening of new unsustainable agriculture area in sloping land especially the steep land and has sparked serious soil erosion phenomena. The Malaysia Good Agricultural Practice (myGAP) certification program which emphasizes the environment, economy and social aspects for agricultural produce has become one of the tools to guide farmers in cPotential ontrolling soil erosion. This study looked at the comparison of vetiver grass (T1) and daylily (T2) as slope stabilizers against bare soil at different elevations using the Revised Universal Soil Loss Equation (RUSLE). A unit plot of 22.1m long and 4.5m wide was built on the 9% sloping area in Cameron Highlands, Pahang (L1) and Titi Gantong, Perak (L2), respectively. Data from rainfall stations were used to define rain erosivity (R) while land cover (C); inclusive of the measurement of height, canopy and root was obtained using hemispherical photography. Length of slope (LS) was constant and conservation measures (P) were based on structures and land use types. To obtain the erodibility factor (K), soil samples were analyzed. The dry soil weight was measured to determine the eroded soil (A). Results showed that L1 had the highest R (13260.3 MJ/mm/ha/hour/year). C of T1 (L1&L2) gave the broadest coverage compared to T2 (L1) and T2 (L2) with higher average measurement of height, canopy and root, while P (L1&L2) was 0.1 (T1) and 0.4 (T2). However, T2 was outstanding at L1 than L2. Despite the K value of L1 (0.02 ton/hour/MJ/mm) being higher, L2 showed higher erosion. Thus, it is concluded that vetiver grass can be a myGAP recommendation as an easy and low-cost slope stabilizer at different elevation whilst daylily is best to be recommended for the highlands

Developing and mechanical properties of low fired and geopolymer bricks from drinking water sludge with different contents of added fly ash

Raw water treatment and coal-based power generation facilities produce a high level of waste to the environment annually. A low recycling scheme has worsened the situation and wastes usually end up in a landfill. Further environmental degradation could be prevented by re-utilising wastes for the production of alternative bricks. Additionally, the development of low-fired brick from wastes can comparatively reduce energy consumption during the firing stage. Geopolymer has successfully replaced ordinary portland cement (OPC) without bargaining its mechanical quality. This study aimed to investigate the effect of fly ash (FA) content and geopolymerization on mechanical characteristics of brick developed from drinking water sludge (DWS). A set of brick samples was fired at 500 oC while another set of samples was prepared under a high alkaline condition to produce geopolymer bricks. Resultantly, both sets of samples demonstrated a decrease in linear shrinkage and increased density with more content of FA. For fired brick samples, the water absorption decreased from 38.6% to 33.3% before rising again at 45% of FA content. However, a continuous decrease was displayed by geopolymer brick as FA increased. The compressive strength of fired bricks showed a decreasing trend as FA content increased and vice versa for the geopolymer brick. The compressive strength of geopolymer bricks increased from 1.22 MPa to 3.63 MPa at 45% of FA content. Comparatively, geopolymer bricks demonstrated higher strength than fired bricks. These results reflect the advantage of the incorporated wastes and geopolymerisation in developing alternative brick for sustainable resources and a better environment

Pengaruh Hasil Tani Organic Compound (HTOC) Terhadap Sifat Fisik dan Kimia Tanah di Lahan Sawah yang Bertanah Asam Sulfat

Tanah asam sulfat umumnya tidak sesuai untuk produksi tanaman, kecuali tanah itu telah diamandemen. Riset ini dilakukan untuk meneliti pengaruh material amandemen tanah, Hasil Tani Organic Compound (HTOC) terhadap sifat fisik dan kimia tanah asam sulfat di lahan sawah, Kedah Malaysia. HTOC dibuat dari beberapa komponen utama yaitu zeolite, kieserite, asam humat dan serbuk kayu karet dengan rasio spesifik. Nilai pH pada tanah asam sulfat adalah sangat rendah yang dapat mengurangi produktifitas tanaman padi. Aplikasi HTOC dapat meningkatkan nilai pH dan kapasitas pertukaran kation (KPK) tanah. Dalam penelitian ini, sampel tanah asam sulfat diperlakukan dengan lima jenis perlakuan variasi dosis HTOC yaitu Plot T0 kontrol (0 t/ha HTOC), T1 (0.25 t/ha HTOC), T2 (0.5 t/ha HTOC), T3 (0.75 t/ha HTOC) dan T4 (1 t/ha HTOC). Dosis HTOC yang paling optimum untuk meningkatkan kualitas tanah asam sulfat adalah 1 t/ha HTOC. Hasil penelitian menunjukkan bahwa nilai sifat fisik dan kimia tanah meningkat sejajar dengan bertambahnya dosis HTOC yang diperlakukan terhadap tanah. Nilai pH dan KPK tanah dilaporkan paling tinggi pada Plot T4 (5.47 dan 12.75 cmolc/kg) dan paling rendah pada Plot kontrol (3.62 dan 8.55 cmolc/kg). Secara kesimpulannya, aplikasi HTOC ini dapat meningkatkan kualitas tanah asam sulfat untuk penanaman padi secara signifikan dengan cara meningkatkan sifat fisik dan kimia tanah terseb