Water absorption and drying shrinkage of recycled foamed aggregate concrete

This paper presents some experimental results and discusses the used of recycled foamed aggregates as natural coarse aggregates replacement in producing concrete. The physical properties of recycled foamed aggregates concrete were investigated. The properties studied are water absorption and drying shrinkage from the concrete early ages until the periods of 56 days. The 100 mm x 100 mm cube specimen was used to study the water absorption at the age of 7, 28 and 56 days. Meanwhile, the 100 mm x 100 mm x 300 mm length prism had been casted and used for drying shrinkage test for recycled foamed aggregates concrete. The foamed aggregates was produced from crushing recycled foamed concrete blocks. It were coated with cement paste to reduce its water absorption ability during casting process. Superplasticizer was used to maintain the workability of fresh concrete with a slump vary between 50 mm to 100 mm. The physical tests were conducted on recycled foamed aggregates to determine their initial properties such as loose bulk density, sieve analysis and water absorption rate. Recycled foamed aggregate concretes were produced with varied water cement ratio. The results obtained indicated that the linear elastic relationship between water cement ratio and water absorption rate. The higher the water cement ratio of concrete specimen will obtained higher water absorption rate. Vice versa, the density is low for drying shrinkage. The water absorption decreased while drying shrinkage becomes more stabilized over curing period

Keselesaan pelajar KUiTTHO terhadap penggunaan bangunan yang telah diubahsuai

Penyelidikan it'li dijalankan bertl.~uan \mtuk meninjau ke:selesaan pelajar terhadap penggunaan bangunan yang telah diubahsuai. Kajian ini juga ingin mengetahui sarna ada bangunan yang telah diubahsuai dapat memenuhi fungsinya) mengenalpa<;ti ma~alah-masalah yang timbul hasil daripada kelja penguhahsuaian hangunan dan mengenalpasti sarna ada faktor kesele~aan h:mellmm holeh mempengaruhi turnpuan pelajar. Daripada analisis, didapati bahawa keselesaan bangunan yang telah diubahsuai boleh mempengaruhi turnpuan pelajar dalarn aktiviti pembelajaran. Pada masa yang sarna, rnasalah tumpuanjuga boleh membawa kesan kepada prestasi pencapaian akademik pelajar. Kajianjuga mendapati kerja pengubahsuaian bangunan telah mendatangkan pelbagai kesan sampingan kepada pelajar dan stafKUiTTHO. Di samping itu, tindakan pengubahsuaian bangunanjuga wajar dilakukan untuk menangani masalah kekurangan bilik h..Llliah, dewan kuliah dan sebagainyamengikut justifikasi universiti serta bangunan yang diubahsuai dapat memenuhi fungsinya. Akhir sekali, sebuah garis panduan umum perlaksanaan program pengubahsuaian bangunan dihasilkan sebagai panduan

Strength Behaviour Of Biomass Fiber-Reinforced Concrete Slab

This paper investigates the compressive strength and flexural strength of biomass fibre-reinforced concrete slab. The main objective of this study is to examine the effect of biomass aggregate and fibre glass on the concrete slab strength. The biomass aggregate is used to replace the natural aggregates. A total of 36 slab samples (250 mm x 600 mm x 50mm thick) and 36 numbers of 150 mm cube samples containing 0%, 30%, 60% and 100% biomass aggregate were prepared.&nbsp; The E-class fibre and Supracoat SP800 were added to increase the strength and to achieve the required workability. All the samples were cured in water with room temperature of around 27oC and tested at the age of 7, 14 and 28 days respectively. The result showed that cube specimens containing 30% biomass aggregate concrete achieved minimum strength of 15 MPa at 28 days. The flexural strength for slab specimens containing 30% biomass aggregate, Supracoat SP 800 and fibre glass gained higher strength compared with control specimens. The 100% biomass aggregate slab achieved 88% of the control specimen strength. The workability was between 150 mm to 170mm slump. The density of the specimens was reduced 20% for cube and 28% for slab compared with control specimens. It can be concluded that the biomass aggregate has good potential as partial aggregate replacement in slab construction when combined with the use of glass fibre and superplasticizer. However, more research needs to be carried out to self-compacting biomass aggregate concrete for sustainable constructio

Strength properties of 10 millimeters timber clinker aggregate concrete

This paper presents some experimental results and discusses the used of timber clinker as partial aggregate replacement in producing concrete. A number of tests were conducted to identify the physical properties of timber clinker aggregate such as density, aggregate impact value (AIV) test and aggregate crushing value (ACV) test, slump, X-Ray Fluorescence (XRF) test and compressive strength of timber clinker aggregate concrete. Two series of concrete mixes with Supracoat SP1000(C0, C10, C20, C30) and without Supracoat SP1000(CA0, CA10, CA20, CA30) with various percentage of 0%, 10%, 20% and 30%

Strength properties of 10 mm timber clinker aggregate concrete

This paper presents some experimental results and discusses the use of timber clinker as partial aggregate replacement in producing concrete. A number of tests were conducted to identify the physical properties of timber clinker aggregate such as density, aggregate impact value (AIV) test and aggregate crushing value (ACV) test, slump, X-Ray Fluorescence (XRF) test and compressive strength of timber clinker aggregate concrete. Two series of concrete mixes with Supracoat SP1000(C0, C10, C20, C30) and without Supracoat SP1000(CA0, CA10, CA20, CA30) with various percentage of 0%, 10%, 20% and 30% 10 mm sieve size timber clinker aggregate were used as partial replacement in producing the concrete. A total of forty 150 x 150 x 150 mm cubes samples were prepared for both series of concrete mixes and tested at 7, 14 and 28 days of water curing. The results showed that the timber clinker aggregate concrete gained highest compressive strength for both series of concrete mixes, that is, C20 and CA20 with results of 37 MPa and 34 MPa respectively. The optimum percentage use of timber clinker aggregate in producing the concrete was 20%. This is because exceeded percentage would decrease the compressive strength. Here, Supracoat SP1000 was added in order to improve the concrete slump. The physical properties test had contribute to the concrete strength development. Based on the results and observation conducted, this study suggested that timber clinker aggregate has successfully use as partial replacement in producing concrete and performed better strength developmen

A review on planer scissor mechanisms for spatial deployable structures

This paper reviewed planar scissor mechanisms (SMs) in the applications of spatial deployable structures. These SMs consists of two beams connected by revolute joint behaves as mechanism during deployment and load bearing structure at deployed configuration. By altering the scissor unit middle joint position or modify scissor elements, various geometry shapes can be formed and additional locking devices is needed for SMs stabilization in final configuration. There are numerous studies have been conducted by experimentally, numerically and analytically to understand the SMs behaviour for spatial deployable structure applications. Although there are many studies dealing with designing new planar SMs in the application of spatial deployable structure and their calculation methods based on researcher’s developed profiles, this topic still been an open topic to be carried out based on their geometric shapes and architectural functions. Therefore, this review aims to provide an overview of SMs behaviours in transforming the folded configuration structure element become spatial deployable structure. The reviewed papers covered the SMs problems, analysis methods and solutions in the application of spatial deployable structures. Based on the reviewed findings, stabilization is the main problem identified for the SMs. The simple geometry approach was used to analyse the system and various stabilization methods proposed subjected to the structures profiles and geometric principle. The deployability conditions and basic scissor unit types must be examined in term to understand their geometric design principles. On the basis of these SMs, the reviewed outcomes are herein will contribute to the better understanding of the SMs behaviours in spatial deployable structures application

THE USAGE OF MS WORD AND JAVASCRIPT IN E-LEARNING COURSEWARE DEVELOPMENT: Received: 06th May 2021; Revised: 20th July 2021, 20th September 2021, 30th December 2021; Accepted: 31st December 2021

This paper introduces a new approach that enables a simplified and automated development of interesting and attractive e-learning courseware by using a Java template. This new approach enables the development of better-quality e-learning courseware in less time and at less cost, and without pre-requisite knowledge of complicated software such as Macromedia, FrontPage, and etc.&nbsp; In the development process, Microsoft Word, HTML coding, and JavaScript are used. In this e-learning courseware development, Microsoft Word software is used for content editing and saved as a .html file. The saved .html file will be encoded using JavaScript for the files to be viewed on web browsers such as Internet Explorer or Chrome. Developing, editing and updating are made simple as the developers only need to amend the.doc file through Microsoft Word and save it as a .html file. The JavaScript will automatically generate the link between the .doc and .html files. This approach has been tested by selected polytechnic lecturers and received positive feedback. The developed e-learning courseware was somehow limited to the functions and features provided by MS Word Software. Therefore, for future study, developers may apply other applications such as Kahoot, Quizizz, etc to make the learning process more engaging and interesting. Overall, this is a user-friendly tool for people or subject matter experts who would like to develop rapid and simple e-learning courseware

Structural performance of half scissor-like elements deployable structure

An experimental investigation on the Half Scissor-Like Elements (H-SLEs) mechanism deployable structure under compression axial load is presented. Two prefab cylindrical shape H-SLEs mechanism deployable steel structures namely M1 (Bolted base column) and model M2 (Unbolted base column) were tested on their performance in term of strength and stability performance. The model prototype consists coldformed and hot roll steel with bolted connection and tested at deployed vertical configuration. Compression axial load was applied at the middle top of loading platform, transferred equally to the six H-SLEs deployable mechanism through supporting beams. The experimental results obtained indicated that three types of failure modes, i.e. excessive bearing capacity failure at lipped C-section flange around bolt hole perimeter, instability due to horizontal displacement at mid-height of H-SLEs deployable mechanism (Bolted joint area) and member buckling. Among these failures, horizontal displacement nominated the overall structure stability while section thickness impacts member bucking and bearing capacity. The experimental ultimate load was 1.63% greater than BS EN 1993 design load resistance for M1 condition while 30% less for M2 condition. The applied load difference between these two model prototypes was 31.15%. Thus, M1 ultimate loads capacity was satisfactory since less than 15% acceptable level while M2 not satisfactory. Beside, horizontal displacement was identify highly impacted scissor mechanism deployable structure instability and suitable member thickness may avoid section premature failure

The performance of isolated half-scissor like elements mechanism under compression axial load

Half-Scissor Like Elements (H-SLEs) deployable mechanism is the prefab scissor based structural mechanism consists of two bars with bolted connection to enable structure change shape. An experimental investigation on the isolated H-SLEs deployable mechanism under compression axial load was presented. A total of twelve specimens were fabricated in two series with six specimens each series were tested on their strength and stability at deployed configuration. The test specimens in series 1 mm thick C75 section were namely S1, S2, S3, S4, S5 and S6 while series 0.75 mm thick C 75 section were namely S7, S8, S9, S10, S11 and S12. The test specimens consist of C 75 and C 100 section which connected with M6, M8 and M10 bolt in grade 8.8. The compression axial load was applied at the center of 3 mm thick loading platform. The experimental results obtained indicated that four types of failure modes observed, i.e. bolt bending failure, section bearing failure, member buckling failure and instability due to horizontal displacement at mid-height of H-SLEs deployable mechanism (Bolted joint area). Among these failure modes, bolt bending failure was dominated the overall structure stability and impacts others failure modes indirectly while section thickness has impacted the buckling and bearing failure. The ultimate load capacity over BS EN 1993 design bearing resistance ratio obtained for M10 bolt was satisfactory. Besides, twisted effect observed during load applied also contributed to the failure modes identified. Thus, the H-SLEs deployable mechanism with stiffener with M10 bolt connection is necessary for future research in the application of spatial deployable structure purposes

Bending strength of magnesium oxide board

Magnesium Oxide (MgO) board has been widely used in prefabricated lightweight steel frame wall systems and as the floor board covering component. It is a non-insulating sheathing board product which consists of sustainable materials with the characteristics of fire resistance, weatherability, strength, resistance to mold and mildew. Although MgO board has recently worldwide used in façade construction but the research data related to the laboratory work such as the bending strength is still limited. The previous studies on the bending strength of MgO board are based on various standards such as American Society for Testing and Materials (ASTM), Building Materials 688 (JC688) Standard and British Standard is subjected to the products characteristics and patterns. Therefore, the bending strength values obtained were inconsistent and not convincing. Thus, this paper aims to examine the bending strength of MgO board with three difference thicknesses (6 mm, 9 mm and 12 mm) based on BS EN 310:1993 subjected to three points bending test. The failure modes during three points bending test was observed and the experimental results obtained were compared with the theoretical values and others relevant standards. A total of thirty six specimens with twelve specimens for each thickness in two group directions namely longitudinal (length) and transverse (width) direction were tested. The specimens were prepared based on BS EN 326-1:1994 and BS EN 325:2012. The maximum flexure load of the specimens was recorded and arithmetic mean bending strength for each thickness was presented. The experimental results showed the tested MgO board was not achieved minimum bending strength for load bearing used. It is recommended to be used in non-load bearing facade cladding construction