Title:
Concrete Q&A: Tensile Bond Strength of Concrete
Author(s):
Scott Tarr
Publication:
Concrete International
Volume:
40
Issue:
7
Appears on pages(s):
71-72
Keywords:
DOI:
Date:
7/1/2018
Abstract:
My company installed a bonded topping on an existing slab. The project specifications required a compressive strength of 4000 psi (27.6 MPa) for the topping concrete. Although our concrete met that requirement, we were directed to remove and replace the topping. The owner’s explanation: The concrete topping was inadequate because pull-off tests failed to achieve 400 psi (2.8 MPa), which is 10% of the compressive strength. Does ACI provide any recommendation on acceptable bond strength for toppings/overlays?