1、SSPC-Guide 21May 4, 20151SSPC: The Society for Protective Coatings1. Scope1.1 This guide collects information on various standards for evaluating slip resistance into a single document to assist owners and specifiers who must specify required slip resistance for a floor surfacing (or coating) in a g
2、iven service environment. It contains recommended maintenance protocols for hard flooring surfaces to increase slip resistance, and a sample form that can be used to investigate accidents and determine corrective actions. Explanations of terminology related to slip resistance, descriptions of standa
3、rd methods and testing equipment for assessing slip resistance, and considerations when interpreting test results are also included. 2. ContentsScopeDefinitionsReferenced StandardsUnderstanding Slip and Fall ResistanceConsiderations for Improving Slip Resistance of FloorsTest Methods and Interpretat
4、ion of ResultsSummaryAppendix Reporting Form for Walkway Evaluation and Incident Investigation for Slips, Trips, and Falls (based on ASTM F1694)3. DefinitionsCoefficient of friction (COF): ASTM G164 defines coefficient of friction as the dimensionless ratio of the friction force (F) between two bodi
5、es to the normal force (N) pressing these bodies together (ASTM G164). See discussion in Section 4.1. Friction: The resisting force that arises when a surface of one substance slides, or tends to slide, against a surface adjoining itself or another substance. Between surfaces of solids in contact th
6、ere may be two kinds of friction- static friction and dynamic friction.Horizontal Drag Slip Meter (used by ASTM F609 and F1028): This machine uses a drag sled to measure the point at which a horizontal force acting upon a resting object first causes the object to move. Usually the horizontal pulling
7、 force is applied by pulling with a scale to measure the frictional resistance to movement of a known drag sled mass. Slip Resistance: The relative force that resists the tendency of the shoe or foot to slide along the walkway surface. Slip resistance is related to a combination of factors including
8、 the walkway surface, the footwear bottom, and the presence of foreign material between them. (ASTM F1637). See discussion in Section 4.3. Static coefficient of friction (SCOF): (1) The force required to initiate relative motion between an object and a surface it is resting on. (2) The tangent of th
9、e angle from the vertical at which slipping begins to occur in variable incidence strut instruments. See discussion in Section 4.1.Traction: The force that allows walking without slipping measured as the coefficient of friction. Traction generally improves between dry, clean, rough surfaces with hig
10、h contact area. Tribometer: An instrument that measures tribological quantities, such as coefficient of friction, friction force, and wear volume, between two surfaces in contact.Tribometry: The science of the measurement of friction; or in the case of pedestrian safety, the measurement of traction.
11、 A tribometrist is one who measures pedestrian traction on walking surfaces.4. Referenced Standards4.1 There are a number of standards for measuring walk-way surface traction, some of which are currently maintained. Several standards listed in this document have been withdrawn by ASTM, but are inclu
12、ded as they continue to be referenced in discussions of slip resistance testing. 4.2 AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI) STANDARDS1ANSI/ASSE A1264.2 Provision of Slip Resistance on Walking/Working SurfacesANSI/NFSI B101.0 Walkway Surface Auditing Procedure for the Measurement of Walkway Sli
13、p ResistanceANSI/NFSI B101.1 Test Method for Measuring Wet SCOF of Common Hard-Surface Floor MaterialsANSI/NFSI B101.2 Test Method for Determining the Impact on Wet Dynamic 1 American National Standards Institute, 1819 L Street, NW, Suite 600, Washington, DC 20036. Standards available online from ww
14、w.ansi.orgTechnology Guide No. 21Guide to Evaluation of Slip and Fall Resistance of Flooring SurfacesSSPC-Guide 21May 4, 20152Coefficient of Friction of Various Chemical or Physical Walkway Surface TreatmentsANSI/NFSI B101.3 Test Method for Measuring Wet DCOF of Common Hard-Surface Floor Materials (
15、Including Action and Limit Thresholds for the Suitable Assessment of the Measured Values)ANSI/NFSI B101.4 Test Method for Measuring the Wet Barefoot Condition of Flooring Materials or ProductsANSI/NFSI B101.5 Standard Guide for Uniform Labeling Method for Identifying the Wet Static Coefficient of Fr
16、iction (Traction) of Floor Coverings, Floor Coverings with Coatings, and Treated Floor Coverings ANSI/NFSI B101.6 Standard Guide for Commercial Entrance Matting in Reducing Slips, Trips and FallsANSI/NFSI B101.7 Standard Test Method for Lab Measurement of Footwear Outsole Material Slip ResistanceANS
17、I/NFSI B101.8 A Floor Safety Management Program for Slip, Trip, and Fall Prevention4.3 ASTM STANDARDS2ASTM C1028 Standard Test Method for Determining the Static Coefficient of Friction of Ceramic Tile and Other Like Surfaces by the Horizontal Dynamometer Pull-Meter MethodASTM D2047 Standard Test Met
18、hod for Static Coefficient of Friction of Polish-Coated Flooring Surfaces as Measured by the James MachineASTM D5859 Determining the Traction of Footwear on Painted Surfaces Using the Variable Incidence Tester (withdrawn 2005)ASTM E303 Standard Test Method for Measuring Surface Frictional Properties
19、 Using the British Pendulum TesterASTM F462 Standard Consumer Safety Specification for Slip-Resistant Bathing Facilities (includes the test method for use of the NIST Brungraber Portable Slip-Resistance Tester)ASTM F609 Standard Test Method for Using a Horizontal Pull Slipmeter (HPS)ASTM F1240 Stand
20、ard Guide for Ranking Footwear Bottom Materials on Contaminated Walkway Surfaces According to Slip Resistance Test Results2 ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. For referenced ASTM standards, visit the ASTM website, ,or contact ASTM Customer Service at service
21、astm.org. For Annual Book of ASTM Standards volume information, refer to the standards Document Summary page on the ASTM websiteASTM F1637 Standard Practice for Safe Walking SurfacesASTM F1646 Standard Terminology Relating to Safety and Traction for FootwearASTM F1677 Standard Test Method for Using
22、a Portable Inclinable Articulated Strut Slip Tester (PIAST) (withdrawn 2006)ASTM F1678 Using a Portable Articulated Strut Slip Tester (PAST) (withdrawn 2005)ASTM F1679 Standard Test Method for Using a Variable Incidence Tribometer (VIT) (withdrawn 2006)ASTM F1694 Standard Guide for Composing Walkway
23、 Surface Investigation, Evaluation and Incident Report Forms for Slips, Stumbles, Trips, and, Falls. ASTM F2508 Standard Practice for Validation, Calibration and Certification of Walkway Tribometers Using Reference Surfaces ASTM G164 Standard Test Method for Determination of Surface Lubrication on F
24、lexible Webs4.4 UNDERWRITERS LABORATORIES3UL 410v Slip Resistance of Floor Surface Materials 4. Understanding Slip and Fall Resistance4.1 COEFFICIENT OF FRICTION (COF)ASTM G164 defines coefficient of friction as the dimensionless ratio of the friction force (F) between two bodies to the normal force
25、 (N) pressing these bodies together (ASTM G164). The resistance to lateral movement caused by the contact between two surfaces measured by dividing the horizontal force by vertical force. A higher coefficient of friction means more friction, and therefore more traction. The coefficient of friction (
26、COF), often symbolized by the Greek letter , or mnull is a dimensionless scalar value that describes the ratio of the force of friction between two bodies and the force pressing them together. The coefficient of friction depends on the materials used; for example, ice on steel has a low coefficient
27、of friction, while rubber on pavement has a high coefficient of friction. Coefficients of friction range from near zero to greater than one under good conditions, a tire on concrete may have a coefficient of friction of 1.7. While it is often stated that the COF is a “material property,” it is bette
28、r categorized as a “system property.” Unlike true material properties (such as conductivity, dielectric constant, yield strength), the COF for any two materials depends on system variables like temperature, velocity, atmosphere and also what are now popularly described as aging and de-aging times; a
29、s well as on geometric properties of the interface 3 UL Labs, Comm 2000 151 Eastern Avenue, Bensenville, IL 60106. Phone1-888-853-3512. Standards are available at SSPC-Guide 21May 4, 20153between the materials. Walking surfaces should be monitored for their slip resistance characteristics.4Static co
30、efficient of friction (SCOF): (1) The force required to initiate relative motion between an object and a surface it is resting on. (2) The tangent of the angle from the vertical at which slipping begins to occur in variable incidence strut instruments. Discussion: According to NBS terminology, SCOF
31、is the ratio of the force required to move the object to its mass.5That is, if it takes five pounds of horizontal force to move a ten-pound block resting on a floor, the Static Coefficient of Friction is 0.50.The two surfaces must be in direct contact with each other, so all static meters must be us
32、ed only under clean, dry conditions. For ASTM standards the Static Coefficient of Friction measurements specify dry conditions only, and standards for the use of instruments under wet conditions refer to slip resistance rather than coefficient of friction. The output of the slip meter is the slip in
33、dex.For surfaces at rest relative to each other s is the coefficient of static friction. This is usually larger than its kinetic counterpart. For surfaces in relative motion k is the coefficient of kinetic friction. The frictional force on each surface is exerted in the direction opposite to its mot
34、ion relative to the other surface. The coefficient of friction is an empirical measurement it has to be measured experimentally, and cannot be found through calculations. Rougher surfaces tend to have higher effective values. Both static and kinetic coefficients of friction depend on the pair of sur
35、faces in contact; for a given pair of surfaces, the coefficient of static friction is usually larger than that of kinetic friction. Most dry materials in combination have friction coefficient values between 0.3 and 0.6. Rubber in contact with other surfaces can yield friction coefficients from 1 to
36、2. While in most applications is less than 1, a value above 1 merely implies that the force required to slide an object along the surface is greater than the normal force of the surface on the object.Dynamic (Kinetic) coefficient of friction: The force required to keep a sliding object in motion, on
37、ce slipping has begun based on the ratio of sliding resistance to vertical force. Discussion: The Dynamic Coefficient of Friction is sensitive to velocity and not possible to measure it until the speed of the slipping surfaces is known. In actual slipping incidents related to falls, the foot acceler
38、ates from the instant of slip initiation until the heel leaves the floor, so meters that move at a constant speed are not measuring dynamic coefficient of friction values relevant to pedestrian activity. For ASTM standards the Dynamic Coefficient of Friction measurements specify dry conditions only,
39、 and standards for the use of instruments under wet conditions refer to slip resistance rather than coefficient of friction. For ANSI standards the Dynamic Coefficient of Friction measurements are conducted using distilled water and a 0.05% surfactant (wetting agent).4 See http:/en.wikipedia.org/wik
40、i/Friction5 R. B. Hunter, “A Method of Measuring Frictional Coefficients of Walk-Way Materials,” Bureau of Standards Journal of Research, March 26, 1929. See pg 331 first paragraph. (This link is read-only.) Discussion of Coefficient of Friction: The coefficient of friction depends on two things: th
41、e quality of both the walking surface and the shoe soles. To prevent slips and falls, a high coefficient of friction (COF) between the shoe and walking surface is needed. On icy, wet, and oily surfaces, the COF can be as low as 0.10 with shoes that are not slip resistant. A COF of 0.40 to 0.50 or mo
42、re is needed for minimal trac-tion, but there is a great deal of debate regarding an accept-able value of COF. The type of activity also creates different requirements for COF. To put these figures in perspective, a brushed concrete surface and a rubber heel will often show a COF greater than 1.0. L
43、eather soles on a wet smooth surface, such as ceramic tile or ice, may have a COF as low as 0.10.6Walking and working surfaces should provide a minimum of 50 percent of this friction. However, if the working surface is very slippery; no footwear will provide a safe COF. 4.2 TRACTIONThe force that al
44、lows walking without slipping is commonly referred to as “traction.” Common experience shows that dry concrete sidewalks have good traction, while dusty or icy surfaces or freshly waxed floors can have low traction. Traction is often expressed using the “coefficient of friction.” A higher coefficien
45、t of friction means more friction, and therefore more traction. Traction can be thought of as the maximum frictional force that can be produced between surfaces without slipping. Traction between two surfaces depends on several factors including:Selection qualities for traction include: slip resista
46、nce, tread design, tread hardness, shape of sole and heel, abrasion resistance, oil resistance, chemical resistance, heat resistance, etc. It may be useful to test footwear sole materials/patterns with an appropriate test method to gather information about their slip resistance characteristics on su
47、rfaces representative of a work environment, and/or with certain contaminants. ANSI 1264.2 considers ASTM Test Methods F609, F1677, and F1679 for testing non-contaminated surface/footwear material combinations while F1677 and F1679 are considered acceptable for testing under contaminated surface/foo
48、twear material combinations. The terms “High-Traction, Moderate-Traction, and Low/Minimal Available-Traction” are defined in ANSI/NFSI B101.1-2009 and ANSI/NFSI B101.3-1012 respectively.4.3 SLIP RESISTANCE Slip resistance is defined as: (1) The relative force that resists the tendency of the shoe or
49、 foot to slide along the walkway surface. Slip resistance is related to a combination of factors including the walkway surface, the footwear bottom, and the presence of foreign material between them. (ASTM F1637) 6 Circular 869, C. J. Lehtola, C. M. Brown, and W. J. Becker, Agricultural and Biological Engineering Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL Aug. 2009 .SSPC-Guide 21May 4, 201542) The frictional force opposing movement of an object across its surface, usually with reference to t
