Bearing Resistance and Failure Mode of Bolted-layered Cemboard Panels

The fabrication of precast slab can be made from wide range of material either neat concrete, foamed concrete or even composite. Until recently, a new interest has been discovered. Instead of wet concrete mixing process in plant, the precast slab can be substituted with fibre cement board or commonly referred as cemboard that meets the specific load requirements with minimum thickness. However, cemboard panel is preferable for lightweight floor system due to its physical strength limitation. Its thickness that relatively small around 15 mm to 25 mm contribute to the drawback and subsequently prohibited the application of cemboard panel as heavyweight floor system. Small specimens are prepared to determine the optimum orientation of bolts and type of bond by analysing the bearing resistance and bond-slip behaviour. It was found that the bearing capacity is governed by polyurethane glue. Meanwhile, the bond-slip behaviour is effectively controlled by the steel bolt. If the steel bolt is solely used as bond mechanism, the bearing capacity will rely on its quantity and capacity and increasing the quantity of steel bolt will eventually lead to the higher value of bearing resistance

Numerical Assessment on Fatigue Failure of Castellated Steel Beams under Sinusoidal Vibration

Increase cost of material in the construction industry has led to the adoption of castellated steel beam as an alternative to substitute conventional steel rolled beam. However, the presence of web opening has resulted to various structural behaviour under static action and uncertainties under dynamic loading, especially fatigue failure. Therefore, this paper presents the numerical assessment on fatigue failure of castellated steel beams. The design of castellated steel beam was based on the parent steel beam of UKB 254 x 102 x 28. Meanwhile, various shapes of web opening (hexagonal, circular and rectangular) with size of 0.75D were considered. The finite-discrete element method program was used as a platform of numerical modelling. The stress range was analysed at 3 Hz of different load amplitudes of sinusoidal vibration. The fatigue life was compared among each shape of web opening at detail categories 90 and 160. At the initial load, the stress range reaches 65 MPa to 150 MPa. When the load increased, the stress range changes diminutively around 240 MPa to 280 MPa. The fatigue life attains at plateau value of 108 cycles, where circular castellated steel beams showed the best performance

Numerical Investigation on Reduced Moment Resistance and Increased Reinforcement Spacing in Reinforced Concrete Wall Subjected to Blast Load

Numerical investigation becomes a highly demanding tool for the best design in engineering. With one validated numerical result available, further investigation is possible to conduct. Especially, for the expensive and limited access for civilian to conduct the test like a blast experiment. With the capability of Arbitrary Lagrange Euler (ALE) solver coupling approach between structure and air in AUTODYN, a detail three-dimensional assessment for RC wall on reduced moment resistance and increased reinforcement spacing are conducted. The RC wall has a cross-sectional dimension of 1829 mm x 1219 mm with wall thickness of 305 mm thickness of strip footing. It is subjected to 13.61 kg Trinitrotoluene (TNT) explosive at 1.21 m standoff distance from the centre. The numerical blast impact on RC wall indicated, although the horizontal and vertical flexural reinforcements are reduced from one of the simulated RC walls, it is capable of demonstrating an equivalent strength to the RC wall tested in the experiment

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

Application of Foamed Concrete and Cold-Formed Steel Decking as Lightweight Composite Slabs: Experimental Study On Structural Behaviour

Foamed concrete composite slabs (FCCS) are currently enjoying great popularity in the construction industry. Unlike conventional composite slabs, FCCS has an advantage in solving the selfweight penalty. With the advanced research in concrete technology, foamed concrete with sufficient strength properties  to meet the requirements of standard code of practise has been successfully introduced. Foamed concrete is known for its lightweight and versatility. This paper presents an experimental study on ultimate load, maximum deflection and failure mode of FCCS. Of interest are the effects of dry density and slab thickness. The slab specimens with a span of 1800 mm, a width of 840 mm and different thicknesses from 100 mm to 150 mm were prepared for the three-point bending test. The dry density of foamed concrete is 1400 kg/m3, 1600 kg/m3, and 1800 kg/m3, which has a compressive strength of about 20 MPa to 40 MPa. Dry density and slab thickness have been observed to have significant effects on ultimate load and maximum deflection. Higher dry density of foamed concrete provides better slip resistance and thus reduces shear bond failure. On the other hand, slab specimens with a higher slab thickness tend to have better bearing capacity due to greater bending stiffness. The main failure mode is dominated by localised bending on the profiled steel deck, slip-displacement and fracture of the foamed concrete

Application of Foamed Concrete and Cold-Formed Steel Decking as Lightweight Composite Slabs: Experimental Study On Structural Behaviour

Foamed concrete composite slabs (FCCS) are currently enjoying great popularity in the construction industry. Unlike conventional composite slabs, FCCS has an advantage in solving the selfweight penalty. With the advanced research in concrete technology, foamed concrete with sufficient strength properties  to meet the requirements of standard code of practise has been successfully introduced. Foamed concrete is known for its lightweight and versatility. This paper presents an experimental study on ultimate load, maximum deflection and failure mode of FCCS. Of interest are the effects of dry density and slab thickness. The slab specimens with a span of 1800 mm, a width of 840 mm and different thicknesses from 100 mm to 150 mm were prepared for the three-point bending test. The dry density of foamed concrete is 1400 kg/m3, 1600 kg/m3, and 1800 kg/m3, which has a compressive strength of about 20 MPa to 40 MPa. Dry density and slab thickness have been observed to have significant effects on ultimate load and maximum deflection. Higher dry density of foamed concrete provides better slip resistance and thus reduces shear bond failure. On the other hand, slab specimens with a higher slab thickness tend to have better bearing capacity due to greater bending stiffness. The main failure mode is dominated by localised bending on the profiled steel deck, slip-displacement and fracture of the foamed concrete

Natural Frequency of Lightweight Composite Slabs Based On Experimental Study and Numerical Modelling

Recently, lightweight composite slabs have become increasingly popular. Lightweight composite slabs are an innovation that provides a better and more convenient construction method for floor systems. Under dynamic loads, lightweight composite slabs may experience meagre inertia forces due to poor stiffness or low mass. Compared to conventional composite slabs, lightweight composite slabs are 40% lighter and more susceptible to structural resonance. Therefore, the vibration behaviour must be controlled to avoid discomfort issues. This study investigates the natural frequency of lightweight composite slabs through experimental study and numerical modelling. In the experimental study, lightweight composite slabs were prepared for the hammer-impact test. The slab thickness ranges from 100 mm to 200 mm. In numerical modelling, lightweight composite slabs were modelled in SAP2000 using a unique technique called the simplified equivalent plate model. The effective material properties were derived from the rule of mixtures and depend exclusively on elastic properties with strength characteristics. The results of the experimental study and numerical modelling agree positively. The natural frequency decreased with slab thickness, signifying that the natural frequency is dominated by mass rather than stiffness. Overall, the natural frequency of lightweight composite slabs is around 27.23Hz to 31.45Hz

Natural Frequency of Lightweight Composite Slabs Based On Experimental Study and Numerical Modelling

Recently, lightweight composite slabs have become increasingly popular. Lightweight composite slabs are an innovation that provides a better and more convenient construction method for floor systems. Under dynamic loads, lightweight composite slabs may experience meagre inertia forces due to poor stiffness or low mass. Compared to conventional composite slabs, lightweight composite slabs are 40% lighter and more susceptible to structural resonance. Therefore, the vibration behaviour must be controlled to avoid discomfort issues. This study investigates the natural frequency of lightweight composite slabs through experimental study and numerical modelling. In the experimental study, lightweight composite slabs were prepared for the hammer-impact test. The slab thickness ranges from 100 mm to 200 mm. In numerical modelling, lightweight composite slabs were modelled in SAP2000 using a unique technique called the simplified equivalent plate model. The effective material properties were derived from the rule of mixtures and depend exclusively on elastic properties with strength characteristics. The results of the experimental study and numerical modelling agree positively. The natural frequency decreased with slab thickness, signifying that the natural frequency is dominated by mass rather than stiffness. Overall, the natural frequency of lightweight composite slabs is around 27.23Hz to 31.45Hz

Numerical investigation of steel reinforcement arrangement in reinforced concrete wall subjected to blast

Three-dimensional (3D) numerical modelling of inverted-T shape reinforced concrete (RC) wall subjected to blast load is study in this paper. The walls have the same moment resistance with different steel reinforcement arrangements. It is subjected to 13.61 kg Trinitrotoluene (TNT) explosive at 1.21 m standoff distance from the centre. The Arbitrary Lagrange Euler (ALE) solvers coupling approach is employed for the interface analysis between air and structure to simulate the damage mechanism in AUTODYN numerical commercial software. The numerical damage indicator indicated, with mesh dependency assessment, the damage pattern vs experimental appeared precisely on the steel reinforcement grid due to the smaller element size compared to the coarse element used