Shear Modulus of Concrete
Shear Modulus of Concrete
(OP)
What do you guys assume for the shear modulus of concrete?
I am looking at rigidity analysis in a shear wall. I am following guidance out of masonry textbook to determine the deflection of each wall and thus its relative rigidity and thus how much shear force it is likely to take.
In order to do this, you need the modulus of elasticity and shear modulus to determine deflection. For masonry, they advise using a shear modulus of 0.4 X modulus of elasticity. Is this comparable for concrete as well?
I know you can determine the shear modulus using Poissons ratio but doing testing to determine poissons seems a little excessive. Maybe I'm on the wrong track, let me know your thoughts.
I am looking at rigidity analysis in a shear wall. I am following guidance out of masonry textbook to determine the deflection of each wall and thus its relative rigidity and thus how much shear force it is likely to take.
In order to do this, you need the modulus of elasticity and shear modulus to determine deflection. For masonry, they advise using a shear modulus of 0.4 X modulus of elasticity. Is this comparable for concrete as well?
I know you can determine the shear modulus using Poissons ratio but doing testing to determine poissons seems a little excessive. Maybe I'm on the wrong track, let me know your thoughts.






RE: Shear Modulus of Concrete
Poisson's ratio for concrete typically is given as 0.18-0.2. I'd say measuring it is probably not necessary, as shear deflections tend to be a vanishingly small proportion of overall deflection.
Brian C Potter, PE
http://simplesupports.wordpress.com
RE: Shear Modulus of Concrete
RE: Shear Modulus of Concrete
RE: Shear Modulus of Concrete
Using the common relationship of E=57000(f'c^0.5)......G= 24800 x (f'c^0.5); however, there are those who argue that the shear modulus doesn't change with strength...rubbish in my opinion.
As for comparison to masonry....in my opinion, the shear modulus of masonry would not be comparable to that of concrete...I would expect much lower for masonry.
RE: Shear Modulus of Concrete
RE: Shear Modulus of Concrete
If you're just trying to distribte lateral loads, and if you have squatty walls (very long and comparatively short), relative stiffnesses can be found using basically any reasonable shear modular assumption, as long as you're consistant overall.
"We shape our buildings, thereafter they shape us." -WSC
RE: Shear Modulus of Concrete