Core Cutting
This is particularly semi destructive test that is used to co-relate the various properties of the concrete such as UPV ,electrical resitivity ,rebound number. It is customary to take cores of 4 inch diameter for comprehensive strength determination . Concrete cores are usually cut by means of a rotary cutting tool with diamond bits. These are described and photographed giving specific attention to compaction,distribution of aggregates ,presence of steel.
Process
A small area of the concrete is exposed and tested. A dolley is placed over the top of the core cutter and it is pressed into the concrete mass using a rammer.
Factors affecting strength of concrete cores
1. Presence of transverse reinforcement steel.
2.Age of concrete.
3.H/D ratio.
4. Strength of concrete.
6. Drilling operations.