Geometry Strength of Honeycomb Sandwich Panel

The geometry strength of honeycomb sandwich panel with several types of core were investigated.   There are four types of sandwich panels; Rectangular Core Sandwich Panel (RCSP), Horizontal Core Sandwich Panel (HCSP), Triangular Core Sandwich Panel (TCSP) and Symmetrical Core Sandwich Panel (SCSP). For all types of panel, the upper and bottom layers and the inner core made from the plywood with different thickness. The performance of the honeycomb sandwich panel subjected to four-point bending test and punching shear test were investigated. The results of flexural test showed that RCSP that having the rectangular core has the highest maximum load of 9.79 kN compared to HCSP and TCSP. The maximum load of RCSP in the punching shear test achieved 34.35 kN which was higher than SCSP.  All the specimens having the core shear failure

Seismic Perfromance On Multi-Storey Precast Buildings (IBS) In Malaysia Subjected To Long-Distant Earthquake Excitation / Nor Hayati Abdul Hamid … [et_al.]

Seismic performance of the reinforced concrete buildings in Malaysia need to examine their structural components under earthquakes excitation. The sub-assemblage of fullscale precast hollow core slabs together with supporting beams are designed, constructed, calibrated and tested under vertical cyclic loadings. The incremental drifts are applied at the end of the cantilever slabs. The load failure, mode of failure and structural damages are recorded and observed during experimental work. Initially, the cracks start from the joints and propagated on top of the slabs and finally, the slab snapped at middle together with delimination of the bottom fibre of the slab. Another experimental work is conducted on three sets of half-scale beam-column joint with different arrangements of reinforcement bars at the joints. These specimens are attached to the foundation beams and clamped to strong floor using eight high yield threaded rods of diameters 30mm. The specimens are designed, constructed and tested under reversible vertical cyclic loading until collapse. The joint with cross-bracing suffers the least damage as compare to others joints. By using the same specimens, the next step is to design the column-foundation joints under lateral cyclic loadings. Tension lateral cyclic loading is applied at top of the column with drifts of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 1.0%, 1.5%, 2.0% and 2.5% at 2 cycles for each drift. Similar pattern of cracks and damages observed during experimental work as compared to the actual damages occurred during earthquake excitation. The first damage is due to unconfined concrete occurred between foundation beam and beamcolumn joint. The second damage is due to plastic hinge zone mechanism which occurs at column-foundation interfaces. These damages are due to the insufficient of longitudinal bars, the spacing between the stirrups are wider and spalling of concrete (lo

A review of cathodic protection in repairing reinforced concrete structures / Nur Insyirah Mohd Nadzri and Norliyati Mohd Amin

Corrosion of steel in concrete structures is an electrochemical process and it occurs when material’s property losses over time due to concrete is exposed to corrosive environments. Cathodic Protection (CP) is a method to repair reinforced concrete structures by making the embedded steel reinforcement cathodic. Impressed Current Cathodic Protection (ICCP) offers flexibility and durability since it is able to deliver essential current in a condition where high resistivity of the reinforced concrete structures. A continuous direct current power supply is needed in order for the ICCP system to be operated. This paper focuses on the review of CP systems for RC structures and the potential of using the cement battery in delivering power to the ICCP system toward reducing the energy consumption. The optimum power generated is discussed as to satisfy the standard current density required for ICCP system

Development of Flat Slab – Column Interaction with Different Thickness

Flat slab – column connection has received much attention in recent years due to its simplicity of construction where beam is not required to support the slab. Flat slab has many usages in the construction field and has been investigated as a potential building material. Despite its many benefits, flat slab is easily subjected to punching shear failure. A simple approach to minimize punching shear failure is by increasing the slab thickness. It is generally accepted that the performance of flat slab is improved by using shear reinforcement; however, little attention has been paid to the selection of thickness. This research focuses on the crack behaviour of flat slab due to different slab thickness. Two specimens with different slab thickness have been constructed and tested to obtain the flat slab strength and crack pattern behaviour. Increasing the slab thickness was found to improve the strength of the flat slab and minimize the deflection and crack appearance on the slab

Mechanical Properties of Lightweight Concrete Using Recycled Cement-Sand Brick as Coarse Aggregates Replacement

This paper presents the result of replacing natural course aggregate with recycled cement-sand brick (CSB) towards the mechanical properties of concrete. Natural aggregates were used in this study as a control sample to compare with recycled coarse aggregates. This study was also carried to determine the optimum proportion of coarse aggregates replacement to produce lightweight concrete. Besides, this study was conducted to observe the crack and its behaviour development during the mechanical testing. Through this study, four types of concrete mixed were prepared, which were the control sample, 25%, 50% and 75% replacement of CSB. The test conducted to determine the effectiveness of recycled CSB as coarse aggregates replacement in this study were slump test, density measurement, compression test, and flexural test and. The strength of concrete was tested at 7 days and 28 days of curing. From the results obtained, the optimum proportion which produced the highest strength is 25% replacement of recycled CSB. The compressive and flexural strength has decreased by 10%-12% and 4%-34% respectively compared to the control sample. The presence of recycled coarse aggregates in sample has decreased the density of concrete by 0.8%-3% compared to the control sample

Mechanical Properties of Lightweight Concrete Using Recycled Cement-Sand Brick as Coarse Aggregates Replacement

This paper presents the result of replacing natural course aggregate with recycled cement-sand brick (CSB) towards the mechanical properties of concrete. Natural aggregates were used in this study as a control sample to compare with recycled coarse aggregates. This study was also carried to determine the optimum proportion of coarse aggregates replacement to produce lightweight concrete. Besides, this study was conducted to observe the crack and its behaviour development during the mechanical testing. Through this study, four types of concrete mixed were prepared, which were the control sample, 25%, 50% and 75% replacement of CSB. The test conducted to determine the effectiveness of recycled CSB as coarse aggregates replacement in this study were slump test, density measurement, compression test, and flexural test and. The strength of concrete was tested at 7 days and 28 days of curing. From the results obtained, the optimum proportion which produced the highest strength is 25% replacement of recycled CSB. The compressive and flexural strength has decreased by 10%-12% and 4%-34% respectively compared to the control sample. The presence of recycled coarse aggregates in sample has decreased the density of concrete by 0.8%-3% compared to the control sample

International Civil and Infrastructure Engineering Conference 2013

The special focus of this proceedings is to cover the areas of infrastructure engineering and sustainability management. The state-of-the art information in infrastructure and sustainable issues in engineering covers earthquake, bioremediation, synergistic management, timber engineering, flood management and intelligent transport systems. It provides precise information with regards to innovative research development in construction materials and structures in addition to a compilation of interdisciplinary finding combining nano-materials and engineering

InCIEC 2013Proceedings of the International Civil and Infrastructure Engineering Conference 2013 /

XXVII, 907 p. 507 illus., 372 illus. in color.onl

Concrete using sawdust as partial replacement of sand : Is it strong and does not endanger health?

This study was conducted to investigate the effectiveness of concrete using sawdust to partially replace the river sand which could reduce both environmental problems and construction cost. In this study, sawdust concrete has been produced where the river sand is replaced with sawdust by 5%, 10% and 15% of the total sand volume. Both wet concrete and hardened concrete (cubes specimens) were tested through material testing and cube testing to obtain the most optimum sawdust concrete design. In addition, specimens have also been tested in environmental laboratory to identify the extent of hazardous use of sawdust to consumer health. This is because the dust used is the waste taken from the unknown root of the level of cleanliness. The result shows that the most optimum design for producing sawdust concrete is that with 10% replacement of river sand. The result is based on the compressive strength obtained. The results of environmental study also show that this sawdust concrete is free from any harmful to health contaminants

Concrete using sawdust as partial replacement of sand : Is it strong and does not endanger health?

This study was conducted to investigate the effectiveness of concrete using sawdust to partially replace the river sand which could reduce both environmental problems and construction cost. In this study, sawdust concrete has been produced where the river sand is replaced with sawdust by 5%, 10% and 15% of the total sand volume. Both wet concrete and hardened concrete (cubes specimens) were tested through material testing and cube testing to obtain the most optimum sawdust concrete design. In addition, specimens have also been tested in environmental laboratory to identify the extent of hazardous use of sawdust to consumer health. This is because the dust used is the waste taken from the unknown root of the level of cleanliness. The result shows that the most optimum design for producing sawdust concrete is that with 10% replacement of river sand. The result is based on the compressive strength obtained. The results of environmental study also show that this sawdust concrete is free from any harmful to health contaminants