Journal of Building Engineering 27 (2020) 100953 Available online 14 September 2019 2352-7102/© 2019 Elsevier Ltd. All rights reserved. Analysis of slip safety risk by portable foor slipperiness tester in state institutions Gültekin Cos ¸kun a , Gencay Sarııs ¸ık b, * a Cumhuriyet University, Vocational School of Sivas, Department of Natural Building Stones, Sivas, Turkey b Harran University, Faculty of Engineering, Department of Industrial Engineering, S ¸ anlıurfa, Turkey A R T I C L E INFO Keywords: Flooring materials Dynamic friction coeffcients (DCOF) Floor surface Safety classifcation Slip safety risk State institutions ABSTRACT Globally, 50% of occupational accidents occur as a result of falling and/or slipping. The slip safety risk should be determined in order to ensure the safety of people on foor coverings and minimize slips and fall accidents. The risk of slipping has been identifed so that people can move safely on foor coverings. In this study, a new safety slip risk scale (SSRS) has been determined in order to move pedestrians on a foor covering more safely. The dynamic friction coeffcients (DCOF) were examined with a portable (GMG 200) test device, in accordance with DIN EN 51131 standards, of commercial foor coverings used in state institutions in a wide range of applications over six zones of fooring materials in dry and wet conditions. In the statistical K average clustering (KMC) method, the SSRS was determined by using DCOF data. According to the SSRS, the safety classifcation of foor coverings were formed by taking the mean of the obtained DCOF data. Finally, when it is imperative to use fooring materials in a dry environment, six zones would be appropriate. 1. Introduction In today’s construction industry, different types of natural stone, artifcial stone, tile stone, laminate, PVC fooring and ceramic are commonly used as foor covering material. One of the most important properties of foor covering materials is that they have a nonslip surface. In recent years, the non-slip properties of foor covering materials in buildings have been required in terms of slip safety [1–6]. Globally, accidents caused by slips and falls are known to be in second place after traffc accidents. Fifty percent of all accidents occur as a result of pedestrians slipping. In Turkey, accidents on slippery surfaces are due to falls. According to the statistics, 238,000 accidents occurred in 2018 and 4150 people died from these accidents [7,8]. In America, an average of one million accidents annually occur due to slips and falls. It was determined that one in every fve accidents were caused by a slip. Due to slip accidents, 2750 people are injured daily and 47 people die each day [9]. In the ancient times, foor covering materials were used in artistic areas due to their durability. In modern times, foor coverings are used in areas with large crowds of people, such as in hospitals, hotels, schools, bus stops, metro stations, pools, restaurants, and supermarkets. One of the notable features of using natural stone, artifcial stone, tile stone, laminate, PVC fooring and ceramic as fooring material is to regulate the risk of slipping. Slip cases occurring in pedestrian surface fooring is caused by fac- tors including, pollutants, environmental factors, insuffcient time, temperature, lighting, shoes, surface characteristics of the foor, people and the person’s mood [10–13]. All of these elements are combined to determine whether the friction force is suffcient in prevent slipping [14]. It is required that foor coverings and sloped ramps used in a wet environment must have non-slip properties pursuant to the Law on the Disabled No. 5378, which was published in the Turkish Offcial Gazette on 07 July 2015. It is now a legal requirement for materials used in foor coverings to be non-slip and to be used in classifcations in accordance with particular standards. State and other institutions are obliged to obtain a certifcate of concentration with regards to the non-slip foor coverings they use. Warning signs and other written notices that the foor coverings are slippery are no longer legally valid. For this reason, determining the friction coeffcients of the foor coverings is an impor- tant matter to be emphasized, in order for state personnel and patients to move more safely [7,8]. In recent years, the importance of research to prevent slip accidents in foor coverings has increased. Slip angle, slip resistance and friction * Corresponding author. E-mail address: gsariisik@gmail.com (G. Sarııs ¸ık). Contents lists available at ScienceDirect Journal of Building Engineering journal homepage: http://www.elsevier.com/locate/jobe https://doi.org/10.1016/j.jobe.2019.100953 Received 25 March 2019; Received in revised form 4 September 2019; Accepted 13 September 2019