Flexural behaviour of plain concrete prism strengthened by textile fine grained mortar

This paper presents a flexural strength study of concrete incorporated with textile fine grained mortar (TFGM) as a strengthening laminate. TFGM is a combination of fine grained mortar (FGM) with alkali resistant glass fabric (AR glass). Fine grained sand with 600 m maximum size was used in FGM and fly ash (FA) or rice husk ash (RHA) has been used as a partial substitute for ordinary Portland cement (OPC). The potential of TFGM as strengthening laminate was tested under monolithic load with three point flexure loading. The TFGM were laid in layers of two, four, six, and eight. Results shown a promising flexure enhancement of up to three times of unstrengthened concrete when eight layers of both RHA and FA were laid. Load bearing capacity and ductility of the samples increased about 200% and 61%, respectively, compared to control samples as well. The outcome shows a highly potential use of agro-waste as cement replacement to produce load bearing structural component

Structural Behavior of Lightweight Composite Slab System

This study investigate the structural behavior of lightweight composite slab system that consist of profiled steel sheet (PSS) attached to dry board (DB) using mechanical screws and with or without infill materials. A total four full-scale panel specimen were tested under four-point bending when subjected under static loading. Result of the four-point test shows that increasing the thickness of profiles steel sheet gives major effect to the deflection and ultimate load. The deflection and ultimate load of 1.0mm thick panel specimen is 16.45% and 34.45% respectively. Therefore, increased the thickness of profiled steel sheet can enhance the stiffness and strength of the lightweight composite slab systems. It also found that the infill material used in these experimental gives minor effect to deflection and ultimate load. The deflection and ultimate load of panel specimen with foamed concrete is 21.18% and 16.66% respectively.  Thus, foamed concrete can be used only for non-structural purposed only such as sound proofing and fire resistance

Characterization of Bond-Slip Behaviour of the Profiled Steel Sheet Dry Board (PSSDB) Composite System

This paper presents an experimental study on the shear connector performance of the profiled steel sheet dry board (PSSDB) composite system through the push-out test. The load-slip curve can be obtained from the push-out test where the system reaches its failure point in which the stiffness value was determined. Ten push-out tests were carried out using different connector spacing ranging from 50–250mm. Two types of profiled steel sheets with a thickness of 1mm were used meanwhile, dry board with 16mm thickness were set as constant. From the result, it can be concluded that the connector spacing plays a major role in influencing the stiffness of the PSSDB system compared to the profiled steel sheet types. The selection of suitable connector spacing is essential in determining the shear performance of the specimen. The specimen with 50mm connector spacing has the highest maximum load, which indicates a high stiffness value. However, it is recommended that the spacing of 100-200mm are used to avoid accelerate failure and ultimately more practical and economical

Compressive Strength, Temperature Performance and Shrinkage of Concrete Containing Metakaolin

The influence of metakaolin (MK) on concrete was investigated as a partial replacement of cement, which is liable for high content of CO2 emission during the manufacturing process. The study aimed to assess the compressive strength, temperature performance and drying shrinkage of MK blended concrete. Different ratios of MK (5%, 10%, and 15%) as cement replacement, and two ratios of superplasticizer (SP), 1.5%, and 2% as cement weight were utilized in this study. The results indicated that using MK increased the compressive strength at 28¬ day. The improvement of strength is ascribed to the pozzolanic reaction and the packing effect of fine MK particles. MK blended concrete experienced a decrease in the temperature rise of heat of hydration (HOH) and low drying shrinkage when compared to the control concrete. The SP ratio does not have significant effect on the temperature of the concrete mixtures: however, using 1.5% SP slightly reduces the drying shrinkage of MK blended concrete compared to 2% SP. In conclusion, Incorporation of MK as partial cement substitute enhances the concrete strength, thus various types of concrete can be produced. Low temperature and drying shrinkage of MK blended concrete help in reducing thermal crack after casting process

Compressive Strength, Temperature Performance and Shrinkage of Concrete Containing Metakaolin

The influence of metakaolin (MK) on concrete was investigated as a partial replacement of cement, which is liable for high content of CO2 emission during the manufacturing process. The study aimed to assess the compressive strength, temperature performance and drying shrinkage of MK blended concrete. Different ratios of MK (5%, 10%, and 15%) as cement replacement, and two ratios of superplasticizer (SP), 1.5%, and 2% as cement weight were utilized in this study. The results indicated that using MK increased the compressive strength at 28¬ day. The improvement of strength is ascribed to the pozzolanic reaction and the packing effect of fine MK particles. MK blended concrete experienced a decrease in the temperature rise of heat of hydration (HOH) and low drying shrinkage when compared to the control concrete. The SP ratio does not have significant effect on the temperature of the concrete mixtures: however, using 1.5% SP slightly reduces the drying shrinkage of MK blended concrete compared to 2% SP. In conclusion, Incorporation of MK as partial cement substitute enhances the concrete strength, thus various types of concrete can be produced. Low temperature and drying shrinkage of MK blended concrete help in reducing thermal crack after casting process

Physico-mechanical properties of polymer concrete containing micro-filler of palm oil fuel ash

Objective of this study is to present a research conducted on ground (fine) and unground (coarse) POFA in polymer concrete (PC) followed by determination on the physico-mechanical properties of PC. Physical properties of micro-fillers and mechanical properties of produced PCs were characterized. Calcium carbonate and silica sand were also used as micro-fillers for comparison purpose. The samples were subjected to compression and flexural. Morphology images of the particles were captured under morphology test to support the findings. Results showed that fine POFA micro-filler has a highly promising potential in becoming PC filler compared to coarse micro-filler. Additionally, its produced PC had comparable strength to PC with calcium carbonate. From the strength development and sustainability stand point, fine POFA has demonstrated its capability to produce quality and sustainable P

Thermal Conductivity Of Lightweight Concrete Block With Various Cooling Agent

Energy was the important sources to human life. Due to increases energy demand in daily life, the energy consumption was increase day by day because of the heat load from solar radiation and heat produced by people. Toward sustainable development, this research was carried out to develop a lightweight concrete (LWC) block with various cooling agent such as glycerine, propylene glycol, coconut shell and gypsum powder. Six lightweight concrete (LWC) block with the size 250mm (L) × 250mm (W) × 100mm (T) were tested for thermal conductivity value.  From the experimental result, it shows that lightweight concrete (LCW) block with various cooling agent obtained thermal conductivity value of 0.17W/mK - 0.36W/mK lower than thermal conductivity value for normal lightweight concrete (0.8W/mK) depending on concrete density.  The lightweight concrete (LCW) block with cooling agent having low thermal conductivity value will reduce energy consumption in building

A Preliminary Study on Vibration Response of Profiled Steel Sheet Dry Board (PSSDB) System under Heel-drop Test

This paper aims to evaluate the vibration response of the profiled steel sheet dry board (PSSDB) composite system under heel-drop test. Three (3) specimens with dimensions of 840mm width and 2000mm length were prepared. The specimen consists of a sample without concrete infill (P45HL), foamed concrete as infill (P45FC), and normal concrete as infill (P45NC) material. The specimen was erected using profiled steel sheet (PSS), 1mm thickness, and connected to a dry board (DB), 16mm thickness using self-drilling screws at 200mm screw spacing along the longitudinal direction. A heel-drop test was conducted, and modal analysis was performed using MEscope software. The FRF measurement was carried out using accelerometers, and the time-domain measured responses were converted to FRF to acquire modal characteristics such as natural frequency and mode shape of the structures. The natural frequency of the first mode shape is 17.7Hz, 14.2Hz, and 4.5Hz respectively for specimen P45H, P45FC, and P45NC. It demonstrates that the natural frequency of the specimen without infill and foamed concrete as infill is more than the human comfort limit value of 8Hz, implying that P45HL and P45FC will be comfortable for building occupants

A Preliminary Study on Vibration Response of Profiled Steel Sheet Dry Board (PSSDB) System under Heel-drop Test

This paper aims to evaluate the vibration response of the profiled steel sheet dry board (PSSDB) composite system under heel-drop test. Three (3) specimens with dimensions of 840mm width and 2000mm length were prepared. The specimen consists of a sample without concrete infill (P45HL), foamed concrete as infill (P45FC), and normal concrete as infill (P45NC) material. The specimen was erected using profiled steel sheet (PSS), 1mm thickness, and connected to a dry board (DB), 16mm thickness using self-drilling screws at 200mm screw spacing along the longitudinal direction. A heel-drop test was conducted, and modal analysis was performed using MEscope software. The FRF measurement was carried out using accelerometers, and the time-domain measured responses were converted to FRF to acquire modal characteristics such as natural frequency and mode shape of the structures. The natural frequency of the first mode shape is 17.7Hz, 14.2Hz, and 4.5Hz respectively for specimen P45H, P45FC, and P45NC. It demonstrates that the natural frequency of the specimen without infill and foamed concrete as infill is more than the human comfort limit value of 8Hz, implying that P45HL and P45FC will be comfortable for building occupants

Amalan penyeliaan pensyarah pembimbing terhadap pelaksanaan latihan industri di Politeknik Sultan Haji Ahmad Shah Kuantan, Pahang

Kajian ini dijalankan bertujuan untuk mengkaji aspek-aspek amalan penyeliaan pensyarah pembimbing terhadap pelaksanaan latihan industri. Kajian ini dijalankan di Politeknik Sultan Haji Ahmad Shah Kuantan, Pahang. Reka bentuk kajian ini ialah berbentuk tinjauan. Kajian ini melibatkan penglibatan dari pensyarah pembimbing dan pelajar dari tiga Jabatan Kejuruteraan iaitu Jabatan Kejuruteraan Elektrik, Jabatan Kejuruteraan Mekanikal dan Jabatan Kejuruteraan Awam. Seramai 30 responden yang terdiri dari pensyarah pembimbing dan 90 responden terdiri dari pelajar dipilih secara rawak terlibat dalam kajian ini. Komponen amalan penyeliaan pensyarah pembimbing dibahagikan kepada tiga (3) konstruk iaitu konstruk pengetahuan, konstruk kemahiran dan konstruk sikap. Kajian rintis telah dijalankan dalam kalangan 30 orang pensyarah pembimbing dan 30 orang pelajar politeknik yang dipilih. Alpha Cronbach digunakan untuk menguji ketekalan dalaman item dalam soal selidik dan nilainya ialah 0.636 bagi soal selidik pensyarah pembimbing. Manakala Alpha Cronbach dalam soal selidik pelajar memberikan nilai 0.903. Dalam kajian ini, analisis diskriptif seperti peratusan, min dan frekuensi digunakan untuk mengenalpasti ciri-ciri aspek amalan penyeliaan pensyarah pembimbing dari aspek pengetahuan, kemahiran dan sikap dengan menggunakan bantuan perisisan Statistical Packages for Social Sciences for Windows Version 22.0 (SPSS). Ujian korelasi Pearson digunakan untuk menguji hipotesis dalam kajian ini. Dapatan kajian menunjukkan skor min konstruk pengetahuan, kemahiran dan sikap merupakan aspek yang berada pada tahap yang sederhana dari pensyarah pembimbing dan pelajar. Ini menunjukkan wujud kesinambungan jawapan soal selidik antara pensyarah pembimbing dan pelajar. Ujian korelasi di antara aspek amalan kemahiran dan pengetahuan serta aspek amalan sikap menunjukan terdapat hubungan yang signifikan. Kesimpulan yang diperolehi daripada kajian ini ialah pensyarah pembimbing perlu memiliki amalan-amalan penyeliaan yang lebih menjurus kepada pembentukan pengetahuan, kemahiran dan sikap yang diperlukan oleh pelajar semasa menjalani latihan industri bagi melengkapkan keperluan pelajar untuk menghadapi alam pekerjaan kelak