DOI: https://doi.org/10.18280/ijdne.170108

Abstract: At present, most academics and practitioners only make assumptions or simplistic correlations between soils in Sabah, Malaysia and soils in West Malaysia in order to determine the Soil Erodibility Factor for Erosion and Sedimentation Control Plan (ESCP) submission apart from using The Soils of Sabah, Volume 5 which is rather archaic or obsolete. This study shall be the foundation for moves to build up a databank for the Department and Irrigation Drainage (DID) Sabah, Malaysia based on soil taxonomy for erosion and sedimentation control calculations. In terms of environmental control application, this research provides specific required information in order to generate precise calculations in projecting the total sediment yield for ESCP for areas around the West Coast of Sabah. The findings of the study would benefit both academicians and ESCP practitioners in generating sediment yield based on the Soil Map of Sabah. 

DOI: https://doi.org/10.18280/ijdne.160412

Abstract: In recent years, the impacts of floods have gained importance because of the increasing number of people who are affected by its adverse effects, especially in the Beaufort area, Sabah, Malaysia. Floods destroyed critical infrastructures that are needed as shelter and also emergency relief for victims. This paper presents the findings of flood modelling undertaken to establish baseline and post-mining flooding conditions during upstream storms and a combination of upstream and downstream storms, respectively. A hydrologic model was established and calibrated based on the 2014 flood. A structural approach by changing the physical dimension through dredging or sand mining between 2m to 3m is used for hydrology modelling and is added to the existing floodgates and bunds. The outcome from sustainable sand prevails when it can reduce flood level for normal flow, upstream case, and both upstream and downstream case. Other findings are changes in velocity, shear and the significantly reduced power generated by the river during flooding.

DOI: https://doi.org/10.26480/esmy.01.2020.77.81

Abstract: During the feasibility and preliminary design stages of a project, when very little detailed information on the rock mass and its geomechanic characteristics is not available, the use of a Rock Mass Classification Scheme (RMCS) can be of considerable benefit. Various parameters were used in order to identify the RMCS. The parameter comprised Rock Quality Designation (RQD), Rock Mass Rating (RMR), Rock Structure Rating (RSR), Geological Strength Index (GSI), Slope Mass Rating (SMR), etc. In this paper, we present the results of the applicability of the Geological Strength Index (GSI) classification for the Trusmadi Formation in Sabah, Malaysia. The GSI classification system is based on the assumption that the rock mass contains a sufficient number of “randomly” oriented discontinuities such that it behaves as a homogeneous isotropic mass. In this study, the GSI relates the properties of the intact rock elements/blocks to those of the overall rock mass. It is based on an assessment of the lithology, structure and condition of discontinuity surfaces in the rock mass and is estimated from visual examination of the rock mass exposed in outcrops or surface excavations. A total of ten (10) locations were selected on the basis of exposures of the lithology and slope condition of the Trusmadi Formation. The Trusmadi Formation regionally experienced two major structural orientations NW-SE and NE-SW. It consists mostly of dark grey shale with thin-bedded sandstones, typical of a turbidite deposit. This unit has been subjected to low grade of metamorphism, producing slates, phyllites and meta-sediments and intense tectonic deformation producing disrupted or brecciated beds. Quartz veins are quite widespread within the joints on sandstone beds. The shale is dark grey when fresh but changes light grey to brownish when weathered. The results are classified as “Poor Rock” to “Fair Rock” in terms of GSI. The poor categories (TR2 and TR7) represent slickenside, highly weathered surfaces with compact coatings or fillings or angular fragments. It is also characterized as blocky/ disturbed/seamy, which is folded with angular blocks formed by many intersecting discontinuity sets. The fair categories can be divided into two (2) types; type 1 (TR1, TR6 and TR8) which represents as smooth, moderately weathered and altered surfaces. It is also characterised as very blocky rock, which indicates interlocked, partially disturbed ass with multi-faceted angular blocks formed by 4 or more joint sets. Type 2 (TR3, TR4, TR5, TR9 and TR10) is represented as smooth, moderately weathered and has altered surfaces but characterized as blocky/disturbed/seamy, which folded with angular blocks formed by many intersecting discontinuity sets. It also has the persistence of bedding planes or schistosity.

DOI: https://doi.org/10.26480/mjg.02.2020.96.102

Abstract: Rock Mass Classification Systems (RMCS) can be of considerable use in the initial stage of a project when little or no detailed information is available. There is a large number of RMCS developed for general purposes but also for specific applications such as Rock Quality Designation (RQD), Rock Mass Rating (RMR), Rock Structure Rating (RSR), Geological Strength Index (GSI), Slope Mass Rating (SMR), etc. In this paper, we present the results of the applicability of the Rock Mass Rating (RMR) System for the Trusmadi Formation in Sabah, Malaysia. The RMR system is an RMCS incorporated with five (5) parameters: Strength of intact rock material, Rock Quality Designation (RQD), Spacing of joints, Condition of joints, and Groundwater conditions. A total of ten (10) locations were selected on the basis of exposures of the lithology and slope condition of the Trusmadi Formation. Trusmadi Formation is Paleocene to Eocene in age. The Trusmadi Formation generally shows two major structural orientations NW-SE and NE-SW. Trusmadi Formation is characterized by the presence of dark colour argillaceous rocks, siltstone and thin-bedded turbidite in a well-stratified sequence. Some of the Trusmadi Formation rocks have been metamorphosed to the low grade of the greenish-schist facies; the sediment has become slate, phyllite and metarenite. Cataclastic rocks are widespread and occur as black phyllonite enclosing arenitic and lutitic boudins with diameters up to a meter or demarcating thin to thicker fault zones or as flaser zones with hardly any finer grain matrix or as zones of closely spaced fractures. Quartz and calcite veins are quite widespread within the cracks deformed on sandstone beds. The shale is dark grey when fresh but changes light grey to brownish when weathered. The RMR system for 10 outcrops ranges from 33.0 to 50.0 and it is classified as “Fair” (Class III) to “Poor” (Class IV) rocks. The Fair Rock (Class III) recommended that the excavation should be top heading and bench 1.5 m – 3 m advance in the top heading. Support should be commencing after each blast and complete support 10 m from face. Rock bolts should be systematic with 4 m long spaced 1.5 m - 2 m in crown and walls with wire mesh in the crown. Shotcrete should be 50 mm – 100 mm in crown and 30 mm in sides. For the Poor Rock (Class IV), the excavation should be top heading and the bench 1.0 m – 1.5 m advance in the top heading. Support should be installed concurrently with excavation, 10 m from the face. Rock bolt should be systematic with 4 m – 5 m long, spaced 1.5 m – 1.5 m in crown and walls with wire mesh. Shotcrete of 100 m – 150 mm in crown and 100 mm in sides. The steel sets should be light to medium ribs spaced 1.5 m only when required.

DOI: -

Abstract: Jabatan Kerja Raya (JKR) Standard Specifications and Inspection and Test Plan recommended the use of granite as the coarse aggregate as the preferred constituent in producing structural reinforced concrete for the construction of infrastructures and superstructures. This literature review will elaborate and share findings in regard to granite and the occurrence of alkali-silica reactions in structural concrete in Malaysia. This study will assist the future development of standard specifications that will have proper coverage regading granite aggregate testing in order to restrict the use of reactive granite aggregate from construction, mainly structural concrete.

DOI: https://doi.org/10.1088/1757-899X/1229/1/012003

Abstract: In most structural repair works or building condition assessments, structural appraisal has been done through visual inspection for tell-tale signs which highlight the possible defect. This method is extended to the standard guideline by Jabatan Kerja Raya (JKR) in their BCA format in determining the physical condition rating. Consulting engineers or structural specialists are to participate when it is determined that the structure requires material testing in order to come up with diagnoses and prognoses. The use of descriptive statistics in both reconnaissance or desktop studies as well as in standard specifications has limitations in determining the actual structural issues. This study demonstrates the advantages of using Multivariate Statistical Analysis (MVA) in summating the right diagnosis and prognosis for structural repair works.

DOI: https://doi.org/10.37934/araset.28.3.177186 

Abstract: Foamed concrete has a tension weakness that can be mitigated by adding a suitable proportion of waste by-products such as mesocarp and trunk fibres. Accordingly, this study was conducted to explore the feasibility of using mesocarp fibre as a reinforcement in foamed concrete. Four varying percentages of mesocarp fibre were used: 0.2%, 0.4%, 0.6%, and 0.8% as an additive in foamed concrete. Two densities were cast and tested: 700 and 1400 kg/m3. After that, all foamed concrete specimens were prepared and tested on 7, 28, and 56 days. Mechanical properties were investigated in this study. The results showed that adding mesocarp fibre to lightweight foamed concrete enhanced its compressive, flexural, and tensile strengths. Because a coarser surface allows mesocarp fibre and matrix interlocking in the cured cement matrix, the surface roughness of the mesocarp has been shown to be favourable for fibre-to-matrix interfacial bonding. According to the findings of this investigation, for a density of 700 kg/m3, 0.4% volume fraction was the optimum quantity of foamed concrete applied to obtain the ideal mechanical properties while 0.6% of mesocarp was optimal for 1400 kg/m3.

DOI:  https://doi.org/10.37934/araset.28.3.187198 

Abstract: This study intended to observe the effectiveness of foamed concrete jacketing using fibreglass fabric with the goal to enhance its durability properties. LFC of two densities of 500 kg/m3 and 1000 kg/m3 were cast and tested. The LFC specimens were wrapped with 1 layer, 2 layers and 3 layers of fibreglass fabric. The parameters evaluated were porosity, water absorption, drying shrinkage and ultrasonic pulse velocity. The results revealed that adding fibreglass fabric to LFC decreased its porosity and water absorption for both densities. Fibreglass fabric did more than only prevent cracks; it also reduced the drying shrinkage and increased the ultrasonic pulse velocity of LFC. Three layers of fibreglass fabric offered optimal results for all properties studied. As a result of the fibreglass fabric's ability to prevent moisture evaporation and consequent dimension changes in the confined LFC, drying shrinkage strain was kept least. The use of fibreglass fabric not only prevented water from escaping but also stopped it from penetrating the cement matrix. This preliminary study shows a huge potential to utilise fibreglass fabric as a strengthening medium to improve the durability performance of LFC.

DOI:  https://doi.org/10.37934/araset.29.1.101109 

Abstract: Lightweight foamed concrete (LFC) is a low-density concrete with numerous applications. However, because its weight is nearly half that of traditional concrete, its strength can also be expected to be reduced. This research investigates the possibility of using LFC reinforced with alkali-resistant woven fibre mesh to improve its mechanical properties. One of the key issues of reinforced lightweight concrete construction is the deterioration of reinforced steel, which has a considerable impact on the reliability of concrete structures. Because it is corrosion resistant, fibreglass netting can effectively solve the corrosion problem as an alternative to welded wire mesh. In this investigation, two densities of LFC (700 kg/m3 and 1400 kg/m3) were cast and tested with three different layers of fibreglass netting, one layer, two layers, and three layers. Compressive strength, flexural strength, and splitting tensile strength were determined. According to the findings, including woven fibre mesh in LFC improves flexural strength, compressive strength, and splitting strength. The addition of three layers of woven fibre mesh resulted in the best mechanical performance for all mechanical qualities studied in this study.

DOI:  https://doi.org/10.37934/araset.29.1.90100 

Abstract: Although foamed concrete was originally developed for void filling and insulation, today's society is gradually shifting its focus to structural qualities. The findings of an experimental investigation that was conducted to determine the impact of various densities and additives on the mechanical properties of foamed concrete are presented in this paper. Additionally, control foamed concrete samples with various densities (600kg/m3, 1200kg/m3, and 1800kg/m3) and additives were created separately to evaluate the effects of each on the mechanical qualities. Coir fibre, sisal fibre, kenaf fibre and flax fibre were used as additives in foamed concrete. According to this study, the density of foamed concrete was influenced by its density due to the volume of porosity. On the other hand, it was discovered that foamed concrete samples with the inclusion of kenaf fibre produced better improvements to the mechanical properties compared to other types of fibre. Since kenaf fibre has a high failure strain and is suitable for use as reinforcement in foamed concrete, it can improve compatibility between the fibres and matrix. The results of this study will help us understand how natural fibres might be used in foamed concrete.