Top PDF The structural behaviour of precast lightweight foamed concrete sandwich panel as a load bearing wall

The structural behaviour of precast lightweight foamed concrete sandwich panel as a load bearing wall

The structural behaviour of precast lightweight foamed concrete sandwich panel as a load bearing wall

Lee et al. (2006) in their paper described an ongoing project to demonstrate an affordable, safe, and energy-efficient housing technology based on expanded polystyrene (EPS) foam panels with a cementitious coating. In this system, the EPS was acting as the core while the cellulose fiber cement board panel was acting as the facings of the panel. The EPS core layer was embedded with the wire trusses which were connected to the wire mesh that enclosed the EPS layer. The cement board facings were screwed to the surface of the EPS layer. The concepts being described are as shown in Figure 2.6, Figure 2.7 and Figure 2.8. Preliminary tests were conducted to analyze the costs, to simulate seismic forces, to conduct the test against environmental conditions, and to build pilot houses.
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Structural behaviour of precast lightweight foamed concrete sandwich panel (PLFP) with double shear truss connectors under eccentric load: preliminary result

Structural behaviour of precast lightweight foamed concrete sandwich panel (PLFP) with double shear truss connectors under eccentric load: preliminary result

Abstract. Recent years in Malaysia, precast concrete sandwich panel gained its popularity in building industries due to its economic advantages, superior thermal and structural efficiency. This paper studied the structural behaviour of precast lightweight foamed concrete sandwich panel (PLFP) with double shear truss connectors under eccentric load. Preliminary results were analysed and studied to obtain the ultimate load carrying capacity, load-deflection profiles and strain distribution across the panel thickness at mid depth. The achieved ultimate load carrying capacity of PLFP due to eccentric load from the experimental work was compared with values calculated from classical formulas (if it is more than 1 comparison) developed by previous researchers. Preliminary results showed that, the use of double shear truss connectors in PLFP was able to improve its ultimate load carrying capacity to sustain eccentric load and achieve certain compositeness reaction in between the wythes.
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The structural behaviour of precast lightweight foamed concrete sandwich panel as a load bearing wall

The structural behaviour of precast lightweight foamed concrete sandwich panel as a load bearing wall

ated from Scandinavia some thirty years ago. Nowadays, foam concrete technology has been widely used in construction industries. It is considered as an attractive material for its lightweight, better thermal properties and ease of construction. In the United States for instance, foamed concrete are used in an increasing number of applications. Cast-in-place foamed concrete are used for insulating roof-deck systems and for engineered fills for geotechnical applications while precast auto-claved products are widely used as load-bearing blocks, reinforced wall, roof and floor units and as non load-bearing cladding panels over a primary structural frame (Tonyan and Gibson, 1992).
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Structural Behaviour of Precast Lightweight Foamed Concrete Sandwich Panel under Axial Load: An Overview

Structural Behaviour of Precast Lightweight Foamed Concrete Sandwich Panel under Axial Load: An Overview

Foamed concrete is classified as having an air content of more than 25%. The air can be introduced into mortar or concrete mixture using two methods. First, preformed foam from a foam generator can be mixed with other constituents in a normal mixer or ready mixed concrete truck. Second, a synthetic or protein-based foam-producing admixture can be mixed with the other mix constituents in a high shear mixer. In both methods, the foam must be stable during mixing, transporting and placing. The resulting bubbles in the hardened concrete should be discrete and the usual bubble size is between 0.1 and 1 mm. The typical mixtures are as given in Table 2, which gives the range of wet density of foamed is between 500 kg/m 3 to 1200 kg/m 3 . Foamed with 1200 kg/m 3 could reach up to 7.5 MPa compressive strength for 28 days and 10 MPa for 91 days. It is also shown from the table that higher density foamed concrete contains less percentage of foam volume. This means less air bubbles in the mixture which resulted with higher compressive strength.
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Structural behaviour of precast lightweight foamed concrete sandwich panel under axial load: an overview

Structural behaviour of precast lightweight foamed concrete sandwich panel under axial load: an overview

Based on the previous research, can be seen that the research of PLFP is still limited and there are still many weakness that arise such as the research done by Lian (1999). This study discussed about the ultimate limit behaviour of reinforced concrete sandwich panels under axial and eccentric loads. However, the numbers of the tested panels was also so small which is only 4 specimens were cast and tested to carry out the result of the research, , no generalised inferences could be drawn. Compared to the author research, the number of tested panels are 8 specimens which is we can compare the result by find the average of the result thus, to obtain the precise and accurate results. The ultimate load capacity for pure axial loaded panels was computed using expressions for design of solid reinforced walls. It was reported that some of the expressions applicable to solid walls could not be directly applied to the sandwich panel.
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Structural behaviour of precast lightweight foamed concrete sandwich panel (PLFP) with shear truss connectors

Structural behaviour of precast lightweight foamed concrete sandwich panel (PLFP) with shear truss connectors

This study is aimed to provide information about the structural behaviour of PLFP with shear connectors. It is able to get a clear and deeper insight on the structural behaviour and failure mechanisms of the PLFP with single and double shear truss connectors under axial and push off loading. The results from this study are very important to assist the design of the PLFP to be used as a precast wall system especially the ultimate load carrying capacity and failure mechanism. An empirical equation is proposed in this study which is able to predict the ultimate load carrying capacity of PLFP under axial loading. The equation can be used to predict the maximum load of sandwich in non-linear behaviour after the service load.
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Study on precast lighweight foamed concrete sandwich panel (PLFP) connection under flexural load

Study on precast lighweight foamed concrete sandwich panel (PLFP) connection under flexural load

In Malaysia, industrialized building system (IBS) had started many decades ago but until now it is still experimenting with various prefabricated method. The governments of Malaysia also encourage the use of IBS and insist that the office building projects shall have at least 70% IBS component. To encounter demands from the growing population and migration of people to urban areas in this country, alternative construction method is required to provide fast and affordable quality housing and environmental efficient. One of the alternatives that already been studied is Precast Lightweight Sandwich Panel. Before we can introduce new innovative construction method, the construction details are an important factor in building design. There has not been any study on Precast Lightweight Foamed Concrete Sandwich Panel (PLFP) connection.Connection is important to transfer loads and also for stability. With regard to the structural behaviour, the ability of the connection to transfer forces is the most essential property. Every aspect of the panel behavior must be analysied. This study will only focus on analyzing the performance of two small scale PLFP walls with U-bent bars connection under bending in term of load-displacement relationship, modes of failure and its ultimate load capacity when connected.
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The structural performance of precast lightweight foamed concrete panel (PLFP) with double shear connectors

The structural performance of precast lightweight foamed concrete panel (PLFP) with double shear connectors

Reduced self-weight of the structures using lightweight concrete reduces the risk of earthquake damages to the structures because the earth quake forces that will influence the civil engineering structures and buildings are proportional to the mass of the structures and building. Thus reducing the mass of the structure or building is of utmost importance to reduce their risk due to earthquake acceleration (Ergul et al., 2003). Among all the advantages, its good thermal insulation due to the cellular thick core makes it an ideal external construction component (Bottcher and Lange, 2006). Some recent investigations suggest their excellent energy-absorbing characteristics under high-velocity impact loading conditions (Villanueva and Cantwell, 2004). Sandwich structures have also been considered as potential candidate to mitigate impulsive (short duration) loads (Nemat-Nasser et al., 2007).
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Experimental study for structural behaviour of precast lightweight panel (PLP) under flexural load

Experimental study for structural behaviour of precast lightweight panel (PLP) under flexural load

Each construction has its own structure part which is responsible to sustain the loading and prevent it from failure. Structures are designed to sustain loads and types of building to be constructed. Thus, ultimate load, cracking pattern and deflection of structures have a relationship to the failure of structure. The ultimate flexural load of panel will be influenced by compressive strength, thickness [4] and density [5]. According to Mustaffa, higher density of foamed concrete also influences the attained ultimate load of slab under test. According to Mohamad et al., two types of crack patterns were discovered on a panel which are flexural crack and shear crack. Flexural cracks started to occur between the point of loading (mid-span) where the concrete experienced high local tensile stresses as loading applied to the slab followed by a shear crack propagated along the slabs. Further increasing the load, the flexural crack propagated upwards reaching top of the slab with increased deflection. Finally, the panels failed by crushing of concrete at the spot nearest to the point of loading [5].
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OVERVIEW OF EMPIRICAL EQUATION PREDICTION FOR ULTIMATE AXIAL LOAD OF PRECAST LIGHTWEIGHT FOAMED CONCRETE SANDWICH PANEL (PLFP)

OVERVIEW OF EMPIRICAL EQUATION PREDICTION FOR ULTIMATE AXIAL LOAD OF PRECAST LIGHTWEIGHT FOAMED CONCRETE SANDWICH PANEL (PLFP)

In the absence of analytical theory, empirical equation is useful in estimating the ultimate load carrying capacity of structural component. Empirical approach means the collection of data on which to base a theory or derive a conclusion in science. It is part of the scientific method. The empirical method is often contrasts with the precision of the experimental method where data are derived from an experiment. This paper review the development of empirical equation from solid reforced panel to sandwich panel. The previous developed empirical equations are be able to predict an adequate ultimate strength of PLFP panel under axial loading due to the safety factor reduction. Series of experiment and Finite Element ANALYSIS (FEA) were carried out to produce sufficient data to analyze the previous developed empirical equation to predict the ultimate load carrying capacity. From findings, a new empirical equation is in need to predict the ultimate axial load of sandwich panel in order to get accurate prediction.
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Structural behaviour of precast concrete sandwich panel using recycled aggregate concrete under transverse load

Structural behaviour of precast concrete sandwich panel using recycled aggregate concrete under transverse load

Kabir (2005) investigated the structural performance of shotcrete lightweight sandwich panels with compressive strength of 12 MPa and tensile strength of 1.2 MPa under shear and bearing loads. The sandwich panels consisted of shotcrete wythes which enclose the polystyrene core. Three specimens are provided for horizontal bending tests, each sandwich panel is 300 cm long and 100 cm wide with the upper and lower concrete wythes at 6 and 4 cm thick respectively. It was reinforced by the diagonal 3.5 mm cross steel wires welded to the 2.5 mm steel fabric embedded in each wythe as shown in Figure 2.16. Tests for flexural and direct shear loading were carried out based on ASTM E-72 and ASTM 564 respectively.
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Advances in Precast Concrete Sandwich Panels toward Energy Efficient Structural Buildings

Advances in Precast Concrete Sandwich Panels toward Energy Efficient Structural Buildings

be given careful attention especially for structural applications. However, current alternative materials used in the PCSP system comes with many undesirable disadvantages for use in structural applications such as bond slip, brittleness, low shear strength and un-economical sections. The alternative materials in PCSP for use in structural applications are expected to exhibit ductile behavior as obtainable in steel to ensure sufficient avenue for warning and evacuation in the event of failure coupled with low thermal conductivity. These features are yet to be achieved from the alternative material such as BFRP, CFRP, GFRP and foamed concrete in reinforced concrete sandwich panels. Thus, more investigations are required in this regard using a conventional material such as steel reinforcement and concrete to develop more design methods like thermal path approach rather than alternative materials that seem unsustainable for practical application in load bearing systems. However, to achieved better and more efficient PCSP using FRP materials, a ductile and slip resistant materials are required to satisfy both the thermal and structural requirements.
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Structural behaviour of precast lightweight concrete sandwich panel under eccentric load: an overview

Structural behaviour of precast lightweight concrete sandwich panel under eccentric load: an overview

This paper presents the overview on structural behaviour of precast lightweight concrete sandwich panel. In Malaysia, demand of affordable housing is increasing due to increasing number of population. Precast concrete sandwich panel is an alternative solution to the conventional construction method due to its ease of construction. The question arises on how to develope a precast panel which is lightweight but with higher strength to sustain the applied load. This paper aims to provide some findings from previous reseach in this field especially on the panel's structural behaviour subjected to eccentric load. It is hoped the overview on this subject matter could be used as guidance for future research on developing a lightweight sandwich panel system in low to medium rise building construction.
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Computational Finite Element Modelling  of Structural Behaviours of Precast  Sandwiched Foamed Concrete Slab

Computational Finite Element Modelling of Structural Behaviours of Precast Sandwiched Foamed Concrete Slab

Load Deflection Profile The maximum deflection of all four panels occurred at mid-span and from the load-deflection curves for Panel 1 to Panel 4, it was observed that Panel 3 had the hi[r]

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Investigation on Failure Modes of Precast Foamed Sandwich Panels under Punching

Investigation on Failure Modes of Precast Foamed Sandwich Panels under Punching

Puput Risdanareni et al [8] attained the compressive strength of 25.2 MPa at the density of 1822 kg/m 3 . These experiment indicate that the strength to weight ratio of foam concrete tends to be higher than the normal concrete and hence it can be used as structural material. Junsuk Kang [9] investigated that there were great difference between composite and non composite panels, the main effect was due to the arrangement of shear connector and the resistance provided by those shear connector. Mugahed Amran et al [10] studied that the increase in aspect ratio significantly reduces the flexural strength and the cracking pattern was along one direction only as in RCC panels, these panels can also be used as an alternative for RCC panels. Qian Huang et al [11] developed a finite element model of a sandwich panel having diagonal FRP bar connectors and their structural behaviour is investigated, their cracking, material and geometric non linearities are observed. Hamid Kazam et al [12] evaluated the shear strength by exposing it to the effect of sustained loading and EPS panels are affected by age more than XPS panels. Sani Mohammed Bida [13] showed that the thermal performance increased by using staggered shear connectors and also increasing the gap shows subsequent increase in thermal performance. Yun Hyun-Do et al [14] investigated the shear strength of sandwich panel with Glass fibre Reinforced Polymer(GFRP) as shear connector by pullout test and showed that the XPS panels tends to perform better than the EPS panels.
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Precast reinforced concrete sandwich panel as an industrialised building system

Precast reinforced concrete sandwich panel as an industrialised building system

Precast concrete wall panel which is currently being used as cladding or curtain walls, does not take any advantage of the panel’s structural capabilities. Non-load bearing precast concrete cladding is noted for its diversity of expression as well as its desirable thermal, acoustic and fire resistant properties. However, it is commonly overlooked that precast concrete elements normally used as cladding applications, such as sandwich wall panels, solid panels and spandrel panels, possess considerable inherent structural capacity. The mandatory amount of reinforcement required to handle and erect a precast component is often more than necessary for carrying imposed loads in case of low or medium-rise structures. Thus, with relatively few modifications, many cladding panels can function as load bearing elements. As with all precast concrete applications, further economies can be realized if the panels are repetitive. By making panels as large as possible, numerous economies are realized: the number of panels is reduced and fewer joints (waterproofing requirements), lower erection cost, and fewer connections are required.
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Effect of uncontrolled burning rice husk ash in foamed concrete

Effect of uncontrolled burning rice husk ash in foamed concrete

Abstract. Recently, foamed concrete has become a popular construction material that can be used in wide range of constructions application. Whilst the Rice Husk Ash (RHA) as agro-waste is contain high amount of silicon dioxide. RHA is produced in significant amount every year from agriculture countries. RHA has potential as a material to produce foamed concrete. In this research RHA has been used as a replacement for fine aggregate which used in construction as ordinary concrete material. In this study, foamed concrete with target density 1400, 1600 and 1800 kg/m 3 has been produced. The compressive strength of foamed concrete with RHA has been tested. Concrete with Ratio 1:3 of RHA/Sand has higher compressive strength than ratios 3:1 and 2:2 of RHA/sand for every density. XRD and XRF test has been used to determinate chemical composition and crystalline structure of RHA. The result showed that RHA is an amorphous material, which amorphous is important thing to pozzolanic process when hydration of cement paste. SEM and EDS test has been conducted to determine microstructure and chemical composition on microstructure of RHA foamed concrete. Amorphous RHA incorporating cement paste produces pozzolanic reaction. It is reduces the porosity and width of interfacial zone in such a way the density is increase.
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CFRP Grid/Rigid Foam Shear Transfer Mechanism for Precast, Prestressed Concrete Sandwich Wall Panels.

CFRP Grid/Rigid Foam Shear Transfer Mechanism for Precast, Prestressed Concrete Sandwich Wall Panels.

Structural demand from applied gravity and wind loading induce flexural, shear, tension, and compression stresses in the precast concrete sandwich panels. Resisting these demands in the most efficient way requires some degree of composite action be achieved between the two separate concrete wythes of the sandwich panel. This can be accomplished by providing sufficient shear reinforcement to transfer the forces from the inner to the outer concrete wythe, through the insulation core. Shear connectors and/or solid concrete zones are used to transfer the applied forces and resist the load as a composite cross section. Three different methods can be used to determine the magnitude of the shear force generated by the applied load and are described in the following sections. The quantity of shear reinforcement required to develop composite action can then be determined based on the shear force and the shear capacity of the connector. To ensure composite action between the inner and outer concrete wythes is achieved, the quantity of shear grid required for a certain cross-section of the panel can be computed as follows:
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Behaviour of Bolted Connection in the Vertical Joint of Precast Wall Panel

Behaviour of Bolted Connection in the Vertical Joint of Precast Wall Panel

This study proposes a bolted connection for precast wall panel subjected to given loading (dead, live & wind). The proposed bolted connection is easy and less time consumption while precast wall panel erection. The mechanical properties of concrete, structural steel, TMT steel bar are studied. Finite element analysis is also performed to investigate performance of the bolted connection using Ansys 19.2.

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Modeling of Precast Concrete Load Bearing Walls Exposed to Fire

Modeling of Precast Concrete Load Bearing Walls Exposed to Fire

Fire-resistance tests of light-weight concrete walls [1] have shown that such walls have a superior performance, when compared to normal-weight concrete walls in terms of yield load, ultimate load, crack load, stiffness, ductility and inter-story drift. Moreover, centrally reinforced walls behave better in fire than doubly reinforced walls with the same amount of reinforcement, while walls with smaller thermal bowing due to smaller in-plane load perform better than the walls with larger thermal bowing due to larger in-plane load [2-3]. The load-bearing capacity of reinforced concrete walls with one-sided fire exposure, reduces significantly with increasing slenderness ratio [4]. The thickness of the concrete wall has also been reported to significantly affect its fire resistance when exposed to fire on both sides [5]. Furthermore, a rotational restraint at the top end and a pin at the bottom end of a wall provide more beneficial effects in reducing the lateral displacement, hence, increasing the fire resistance, as compared to having pins at both the top and bottom ends [4]. On the other hand, cantilever walls may show larger deflections as a result of thermal bowing and P-delta effects [6].
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