BUCKLING OF STEEL FIBRE EXPANDED POLYSTYRENE CONCRETE WALL PANEL

2015 ◽  
Vol 76 (10) ◽  
Author(s):  
Rohana Mamat ◽  
Siti Hawa Hamzah ◽  
Jamilah Abd. Rahim

Steel Fibre Expanded Polystyrene Concrete (SFEPS) wall panel is envisaged as load bearing walls, although it is lightweight by design. The performance of this wall is investigated, incorporating opening to fulfil the demand for ventilation and services conduits or equipments. It focused on the buckling behaviour by comparing the carrying load capacities and deformation profiles of wall panel with and without opening. Primarily, the samples were cast from concrete mixed with expanded polystyrene (EPS) beads, enhanced with hooked end round shaft steel fibre and reinforced with a single layer rectangular steel fabric (BRC) of size B9. The wall panel size is 2000 mm in height (limited due to testing frame allowable height), 1500 mm wide and 100 mm thick which gives the slenderness ratio of 15. The wall falls under the slender wall category for lightweight concrete since the slenderness ratio is greater than 10 [1]. A central opening with a size of 600 mm high by 600 mm wide is created to accommodate the opening criterion. Experimental tests were conducted simulating fixed ends condition. The average compressive strength of SFEPS, fcu is 20.87 N/mm2 with a density, ρ of 1900 kg/m3. These lightweight SFEPS wall panels sustained load between 958.0 kN and 1938.9 kN. Wall panels experienced maximum displacement of 22.3 mm at midheight. The wall panels failed in buckling as it should be for slender wall. There was also concrete crushing at the upper and lower ends of the panels. The SFEPS wall panel is suitable to be used as load bearing structures.

2015 ◽  
Vol 76 (9) ◽  
Author(s):  
Jamilah Abd Rahim ◽  
Siti Hawa Hamzah ◽  
Hamidah Mohd Saman

This study was conducted to determine the optimum mix proportion of lightweight concrete (LWC) containing expanded polystyrene (EPS) and steel fiber which is designated as Expanded Polystyrene Fibred Lightweight Concrete (EPSF-LWC) for load bearing wall application. In order to produce LWC, EPS beads were chosen as lightweight aggregate because it gives advantages in term of energy absorbing capacity which suitable for structure that would be exposed to impact like shear wall. However, EPS beads possess zero strength. Therefore, steel fibre was added to improve LWC strength and also to reduce occurrence of micro and macro crack. In the mix design method, the percentage of EPS beads adding to the mix are differ while the percentage of steel fibre is same. The result showed optimum mix design was the one that contained 30% of EPS and 0.5 % of steel fibre and is designated as M8. The compressive strength EPSF-LWC of mix proportion designated as M8 is 19.51 MPa with density 1939 kg/m3. It is greater than 17 MPa as the requirement for structure component application that stated in the BS8110. Hence, reinforced and unreinforced EPS-LWC wall panels were constructed to determine the maximum loading that wall can sustain and deflection profile EPSF-LWC wall panel for the loaded to failure. The wall was set up under pinned-fixed end support condition. The sample was modelled using finite element analysis (FEA) for validation with experimental programme.  The maximum loading capacity was found to be 908.20 kN and 853.40 kN for each reinforced (WR5) and unreinforced (WUR5) of EPSF-LWC wall panel. These loading were 31% to 35% less than finite element analysis. However, WR5 and WUR5 EPSF-LWC wall panel was deformed in single curvature profile for both experimental and FEA. Maximum deflection for WR5and WUR5 of EPSF-LWC recorded is 10.27 mm and 12.95 mm occurred at 0.7 heights (H) of wall panel. According to Euler buckling load theory, the location of maximum lateral displacement of wall panel sample is influenced by the type of fixity at end support of the sample.


2022 ◽  
Vol 1048 ◽  
pp. 387-395
Author(s):  
Joel Joseph Shelton ◽  
Mohammad Izazs ◽  
C. Daniel ◽  
A. Arun Solomon

Nowadays, one of the fastest growing technique is an Insulated Concrete Form (ICF). It has advantages like cost-effective, less maintenance, soundproof, energy-efficient, waterproof and disaster-resistant. ICF wall panels are made by interlocking Fibre Cement Board (FCB) sheet which poured in placed concrete. In this study, the behaviour of the ICF wall panel under axial compression is examined with experimental and analytical methods. ICF wall panels cast with various thickness and dense FCB are tested under axial compression. ICF panels with 1.2gm3/cm dense FCB with changing width of 6mm and 10mm were casted for experimental analysis. The experiments were carried out in an universal testing machine with the capacity of 600 kN. The maximum peak load of 540 kN is observed in FCB of 10mm thick and the maximum displacement of 13mm is observed in FCB80 at the peak load. An analytical investigation is carried with Euler’s crippling load equation and an average variation of 12% is observed between analytical and experimental results. It is concluded that the ICF system of construction provides desirable plastic behaviour against axial compressive loading. Hence ICF is recommended for construction to get the maximum benefits of the wall while it reaches ultimate strain.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Irindu Upasiri ◽  
Chaminda Konthesingha ◽  
Anura Nanayakkara ◽  
Keerthan Poologanathan ◽  
Brabha Nagaratnam ◽  
...  

Purpose In this study, the insulation fire ratings of lightweight foamed concrete, autoclaved aerated concrete and lightweight aggregate concrete were investigated using finite element modelling. Design/methodology/approach Lightweight aggregate concrete containing various aggregate types, i.e. expanded slag, pumice, expanded clay and expanded shale were studied under standard fire and hydro–carbon fire situations using validated finite element models. Results were used to derive empirical equations for determining the insulation fire ratings of lightweight concrete wall panels. Findings It was observed that autoclaved aerated concrete and foamed lightweight concrete have better insulation fire ratings compared with lightweight aggregate concrete. Depending on the insulation fire rating requirement of 15%–30% of material saving could be achieved when lightweight aggregate concrete wall panels are replaced with the autoclaved aerated or foamed concrete wall panels. Lightweight aggregate concrete fire performance depends on the type of lightweight aggregate. Lightweight concrete with pumice aggregate showed better fire performance among the normal lightweight aggregate concretes. Material saving of 9%–14% could be obtained when pumice aggregate is used as the lightweight aggregate material. Hydrocarbon fire has shown aggressive effect during the first two hours of fire exposure; hence, wall panels with lesser thickness were adversely affected. Originality/value Finding of this study could be used to determine the optimum lightweight concrete wall type and the optimum thickness requirement of the wall panels for a required application.


2015 ◽  
Vol 660 ◽  
pp. 208-212 ◽  
Author(s):  
Mihai Fofiu ◽  
Andrei Bindean ◽  
Valeriu Stoian

This paper presents the retrofitting procedure used on a precast reinforced concrete wall panel (PRCWP) in order to restore its initial load bearing capacity. The specimen used in this experimental test is one from the residential multistoried buildings constructed in Romania from the 1970 onwards. All of the characteristics of the element are from the specific era, only scaled down with a factor of 1:1,2. The element was subjected to in-plane reversed cyclic loading to simulate its seismic behavior and obtain its maximum load bearing capacity. After the test we retrofitted the element using Carbon Fiber Strips Externally Bonded (EBR) and anchored with Carbon Fiber Reinforced Polymers (CFRP) mesh. The porpoise of the paper is to compare the maximum loading bearing capacity of the unstrengthen and strengthen elements in order to compare them and examine the efficiency of this retrofitting procedure.


2020 ◽  
Vol 12 (19) ◽  
pp. 7907
Author(s):  
Hyun-Do Yun ◽  
Hye-Ran Kim ◽  
Won-Chang Choi

Many connection systems are available that can transfer tension and shear loads from a precast concrete wall panel to a floor slab. However, due to the insufficient anchor depth in relatively thin precast concrete panels, it is difficult to attain adequate ductility and stiffness to ensure structural integrity. Based on the authors’ previous research results, the supplementary reinforcement of embedded steel plates in precast concrete wall panels can enhance stiffness while maintaining allowable displacement and ductility. In this study, three full-size tilt-up precast concrete panels with embedded steel plates were fabricated. Lateral cyclic loads were applied to full support structures consisting of a precast concrete wall panel and a foundation. The test results were compared with the results predicted using existing code equations found in the American Concrete Institute 318-14 and the Prestressed Concrete Institute Handbooks. The test results confirm that the supplementary reinforcement of thin precast concrete wall panels can provide (i) the required strength based on current code equations, (ii) sufficient ductility, and (iii) the energy dissipation capacity to resist cyclic loading.


2014 ◽  
Vol 5 (3) ◽  
pp. 261-290 ◽  
Author(s):  
Poologanathan Keerthan ◽  
Mahen Mahendran

Cold-formed Light gauge Steel Frame (LSF) wall systems are increasingly used in low-rise and multi-storey buildings and hence their fire safety has become important in the design of buildings. A composite LSF wall panel system was developed recently, where a thin insulation was sandwiched between two plasterboards to improve the fire performance of LSF walls. Many experimental and numerical studies have been undertaken to investigate the fire performance of non-load bearing LSF wall under standard conditions. However, only limited research has been undertaken to investigate the fire performance of load bearing LSF walls under standard and realistic design fire conditions. Therefore in this research, finite element thermal models of both the conventional load bearing LSF wall panels with cavity insulation and the innovative LSF composite wall panel were developed to simulate their thermal behaviour under standard and realistic design fire conditions. Suitable thermal properties were proposed for plasterboards and insulations based on laboratory tests and available literature. The developed models were then validated by comparing their results with available fire test results of load bearing LSF wall. This paper presents the details of the developed finite element models of load bearing LSF wall panels and the thermal analysis results. It shows that finite element models can be used to simulate the thermal behaviour of load bearing LSF walls with varying configurations of insulations and plasterboards. Failure times of load bearing LSF walls were also predicted based on the results from finite element thermal analyses. Finite element analysis results show that the use of cavity insulation was detrimental to the fire rating of LSF walls while the use of external insulation offered superior thermal protection to them. Effects of realistic design fire conditions are also presented in this paper.


2018 ◽  
Vol 193 ◽  
pp. 03017
Author(s):  
Boris Zhadanovsky ◽  
Sergey Sinenko ◽  
Alexey Slavin

The characteristics of wall panels, the facing element of which is porous concrete, are given. For exterior wall panels, laboratory suggested the exposed porous concrete of grades B7,5 and B10 based on white and grey cements M400. As aggregates, one uses limestone and granite mined in the corresponding quarry. Air-entangling additives are applied in concrete manufacturing, due to which placeability of concrete mix is improved and volumetric weight of concrete is reduced. In its turn, it allowed reducing water absorption and enhancing freeze resistance of products. Presence of fine-splitted air in formation of closed pores (pore forming) improves the structure of exposed concrete, bringing its properties closer to the ones of porous claydite-concrete as the essential material of exterior wall panel. Homogeneity of concrete by durability came to 0,70 with variability coefficient equal to 0,11, what exceeds regulatory requirements. Its factory features and way of production are indicated. The range of application and the actual cost of such panels are identified.


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