# Coefficients of Friction for Concrete

An educational, fair use website

Bibliographic Entry Result
(w/surrounding text)
Standardized
Result
Serway, Raymond A. and Robert J. Beichner. Physics for Scientists and Engineers with Modern Physics 5th edition.New York: Saunders, 133.
Table 5.2 Coefficients of Friction
surfaces μs μk
rubber on concrete 1.0 0.8
0.8 kinetic (dry)
1.0 static (dry)
Friction Center Coefficient Database. Southern Illinois University Carbondale center for Advanced Friction Studies. 2005.
Friction Couple Conditions static coefficient kinetic coefficient
rubber/concrete varying 1.00–4.00 0.80
0.8 kinetic (dry)
1.0–4.0 static (dry)
Friction and Friction Coefficients of some Common Materials. The Engineering Toolbox. 2005
Materials and Material combinations Kinetic Frictional Coefficient
clean and dry surfaces lubricated and greasy surfaces
Rubber Dry Concrete 0.6–0.85
Rubber Wet Concrete 0.45–0.75
0.6–0.85 kinetic (dry)
0.45–0.75 kinetic (wet)
Kurtus, Ron. Coefficient of friction values for clean surfaces. School for Champions. 2 November 2005.
Coefficient of Sliding Friction (clean surfaces)
Material 1 Material 2 Static Kinetic
Rubber Concrete (dry) - 0.6–0.85
Rubber Concrete (wet) - 0.45–0.75
0.6–0.85 kinetic (dry)
0.45–0.75 kinetic (wet)
PHYS 101 lecture 6 friction 2001 David Boal, Simon Fraser University
smooth surfaces μstatic μkinetic
rubber on concrete (dry) 1.0 0.80
rubber on concrete (wet) 0.30 0.25
0.8 kinetic (dry)
0.25 kinetic (wet)
1.0 static (dry)
0.30 static (wet)

Friction is the resistive force to motion; it tries to prevent objects from freely sliding on one another. There are two basic types of friction, static friction and kinetic friction. Static friction is the force of friction between two stationary objects and kinetic friction is the force between two moving objects, and is usually smaller than static friction. The coefficient of friction is the ratio of the force of friction divided by the normal force. Therefore friction is only dependant on the normal force and the materials in contact, not surface area.

Concrete is a building material which is made up of aggregate, usually sand and gravel, and cement binder. Concrete is used to make a huge assortment of things in our everyday lives such as pavements, building structures, foundations, roads, overpasses, parking structures, brick/block walls and bases for gates, fences and poles. Concrete is extremely important in the world and is more or less under appreciated by the general public. Over six billion tons of concrete are made every year, that's equal to one ton for every person on Earth. Concrete has been around for centuries and instead of using cement the ancients would use clays and lime other materials. Due to the nature of concrete it has relatively high coefficient of friction. Concrete is like "liquid stone" in that although it may be soft and shapeable at first, once it sets it is rough and rocky.

Matthew Michaels -- 2006