The two-way flexural performance of the PSSDB floor system with infill material Marwan Samir Al-Shaikhli, Wan Hamidon Wan Badaruzzaman ⁎, Shahrizan Baharom, Ahmed W. Al-Zand Department of Civil and Structural Engineering, Universiti Kebangsaan Malaysia, Jalan Reko, 43600 Bangi, Selangor, Malaysia abstract article info Article history: Received 3 November 2016 Received in revised form 30 May 2017 Accepted 19 June 2017 Available online xxxx This paper investigates the structural performance of the Profiled Steel Sheeting Dry Board (PSSDB) system; a lightweight composite structure which is made by binding a Profiled Steel Sheeting (PSS) to a Dry Board (DB) by mechanical screws. Many studies indicated that it can be used as flooring units. However, most of them fo- cused on utilizing the system as a one-way floor panel. It's rare to find studies that consider the two-way position, and so far none has ever considered the effect of the infill material in that situation. Therefore, the purpose of this paper is to investigate the flexural performance of the two-way PSSDB floor panel with the presence of the infill material. An Experimental (EXP) and Finite Element (FE) approaches were employed. For the EXP tests, it was found that applying a steel plate (SP) can enhance the stiffness and strength of the PSSDB system by approxi- mately 31% and 15%. The results were used to compare with the ones of a previous study, and it was shown that applying infill material can improve the strength by 13.2%. Applying both Steel Plate (SP) and infill material instead of SP alone can enhance it by 13.6%. As for the FE approach, it was demonstrated that changing the thick- ness of the DB and SP has a minor effect by no more than 5%, while changing the PSS's thickness can affect the performance by up to 18.3%. And finally, the effect of changing the type of infill material is less than 1%. © 2017 Published by Elsevier Ltd. Keywords: Profiled steel sheeting Dry board Infill material Two-way PSSDB 1. Introduction Over the years, many researches and studies were conducted by the construction industry with the aim of producing structures that meet the cost-effective criteria. These studies can be divided into two groups; the first is combining different materials together to produce a new one called “composite material”, which has better characteristics than that of its constituent utilized individually. The second one is about connecting two or more materials together that they act as a single unit and where the utilization of each material will be applied by its specified position. This one is called “composite structure”. This paper deals with the latter type. Composite structures have various advan- tages; it has greater stiffness and strength, and presents a practical and economical solution for construction. Up until now, various types of composite structure have been intro- duced. One of those in 1986 by Wright and Evans is called the Profiled Steel Sheeting Dry Board (PSSDB) system: a light-weight composite structure which consists of a Profiled Steel Sheeting (PSS) tied to a Dry Board (DB) by mechanical screws [1]. At the beginning, it was designed to replace the timber joist floor panels which are exposed to insects attack, moisture and other elements that affect the age of a building. Later in 1989, another study by Wright et al. [2] has demonstrated that the stiffness of the PSSDB system is greater than PSS alone by up to 70%. In addition, the system has other advantages; it does neither require temporary propping, skilled labors, nor a lot of construction time, and renovations can be easily handled (Fig. 1). A lot of studies have focused on using the PSSDB panels as flooring system [3–10]. However, only few of them have considered the two- way action. Investigating the structural performance of the PSSDB system as two-way floor panels was first conducted by Ahmed et al. in 2002, in which small-scale PSSDB samples were used [11]. Based on the previous study, a recent one was conducted in 2015 using Finite Element (FE) analysis in order to inspect the behavior of the system under various factors [12]. Another study in 2016 was carried out, where in addition to using larger Experimental (EXP) specimens and different materials, an optimization method was suggested by applying a mild steel plate at the bottom flange of the PSS by using self-tapping & self-drilling screws, and which has proved to be an efficient one [13]. However the effect of infill material on the two-way bending behav- ior of the PSSDB floor system is yet to be inspected. Therefore, this paper aims to investigate the flexural performance of the two-way PSSDB floor panel with the presence of the infill material. The study will be done in three steps: the first is conducting EXP tests using PSSDB specimens, whereas the second is creating FE models and checking their accuracy by comparing them with the EXP results. The final step is conducting Journal of Constructional Steel Research 138 (2017) 79–92 Abbreviations: CS, Control sample; CONS, Concrete sample; CONPS, Concrete-plate sample; DB, Dry board; EPS, Expanded polystyrene; EXP, Experimental; FE, Finite element; LVDT, Linear variable differential transformer; PS, Plate sample; PSSDB, Profiled steel sheeting dry board; ST, Strain gauge; SP, Steel plate. ⁎ Corresponding author. E-mail addresses: whamidon@eng.ukm.my (W.H. Wan Badaruzzaman), shah@eng.ukm.my (S. Baharom). http://dx.doi.org/10.1016/j.jcsr.2017.06.039 0143-974X/© 2017 Published by Elsevier Ltd. Contents lists available at ScienceDirect Journal of Constructional Steel Research