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Concrete friction coefficients

Concrete friction coefficients

Concrete friction coefficients

(OP)
Does anyone happen to know what the static coefficient of friction for concrete on concrete is? Approximately?

RE: Concrete friction coefficients

Rufus182,

I have not heard about the static coefficient of friction between concrete to concrete. But know the friction coefficient bet. rubber and concrete which is 1.0.

Extending the same logic and since the concrete is heavy the static coefficient of friction may be around 1.0.

visit following web page.

http://www.govictory.com/DiggerJr/Friction/Friction.htm

Bannu

RE: Concrete friction coefficients

I would say 0.6, per ACI 318-95 Section 11.7.4.3.

RE: Concrete friction coefficients

yeah... I agree with DaveAtkins, but the friction coefficient is 1.0 for roughend concrete.

RE: Concrete friction coefficients

Based on the advice given in British Standard BS 5975, the coefficient of friction are given as lower bound values:

Concrete/concrete = 0.4
Concrete/plain steel = 0.1
Concrete/softwood = 0.4
Concrete/hardwood = 0.3
Concrete/granular soil = 0.4

Andy Machon

 
 

RE: Concrete friction coefficients

Its very difficult to give even an approximate answer. It will have a bearing on the condition of two concrete blocks. It will be significantly different in both of the following conditions:-

1. between smooth concrete blocks (seperately cast)- 0.3 to 0.4
2. single casting of concrete block cracked into two parts 0.5 to 1.0.

Moreover present of moisture and presence of crushed material between the surfaces may bring down the friction factor dramatically. You have to be more specific about the conditions and then you can arrive at a more reasonable approximation.

RE: Concrete friction coefficients

(OP)
Thanks for the good advice & tips dudes. We are down a tunnel at the moment so yes, moisture is a condition. The bits were cast separately. We'll go for the side of caution: 0.3 will do for now.

Watch your six
Rufus182

RE: Concrete friction coefficients

Flamby (or anyone else),
Any chance you can point to a reference for the use of 0.3 to 0.4 for seperately cast concrete?  We're trying to verify that concrete traffic barriers can be used as ancorage points against a lateral load.
Thanks,
Jack

RE: Concrete friction coefficients

Several years ago the PCA advised me, via email, that I should use 0.4 as COF between a precast concrete building and a cast in place foundation.

RE: Concrete friction coefficients

Ginger,
Concrete/plain steel = 0.1 is too small. That is the friction of coefficient between Teflon to Teflon. We use 0.5 betw steel and conc.

RE: Concrete friction coefficients

steel on wet oily concrete? 0.1 is not conservative

Cheers

Greg Locock

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