Cut with a diamond core drill, usually about 4 in in diameter, cores are the standard follow-up when cylinder breaks come in low or the in-place concrete is in doubt. For acceptance, three cores must average at least 85 percent of f'c with no single core under 75 percent. Cores also reveal cover depth, voids, cracks, delamination and ASR in existing structures.
Engineer wants three cores out of the level 2 slab where the low breaks were, so scan for tendons before you drill.
Also heard as
- core sample
- drilled core
- coring
Related terms
Break
A cylinder strength test result, or the crushing of cylinders in the lab.
f'c
Symbol for specified compressive strength, the design strength the engineer requires, usually at 28 days.
PT
Post-tensioning: reinforcing concrete with steel tendons that are stretched tight after the concrete hardens.
Compressive strength
The crushing load concrete can carry per unit area, the main property specified and tested for concrete.
Same word, different worlds
The central glass region of an optical fiber where the light actually travels.
Printed Circuit BoardsFully cured laminate with copper on both sides, etched into inner layers and bonded with prepreg into a multilayer.
Asphalt PavingA cylinder of pavement drilled out of the finished mat and sent to the lab for density and thickness.
NonwovensTube, usually paperboard, on which nonwoven fabric is wound to make a roll.