How do you test concrete cores?

Concrete cores are usually cut by means of a rotary cutting tool with diamond bits. In this manner, a cylindrical specimen is obtained usually with its ends being uneven, parallel and square and sometimes with embedded pieces of reinforcement.

What is core cutter test for concrete?

Core test is a well-established method, generally performed in the area of concrete industry to assess whether the suspect hardened concrete complies with strength- based acceptance criteria or not; and sometimes it becomes the unique tool for safety assessment of existing concrete structures.

What is the recommended L D ratio for core test?

2.5-3:1
One of the parameters which affect the uniaxial compressive strength (UCS) of rock materials is the length to diameter ratio (L/D) of test cores. ASTM recommends a ratio of between 2 and 2.5, and ISRM suggests 2.5-3:1.

How do you core a concrete sample?

Drill cores perpendicular to surface and not near formed joints or obvious edges of a concrete placement (unit of deposit). D. Take cores near the middle of a concrete placement (unit of deposit) when possible. In columns or walls, for instance, samples should be taken near mid-height—not at the top or bottom.

What is the purpose of a concrete core test?

Concrete core test is a very famous and well-established testing method for the compressive strength of the hardened concrete. Concrete core testing enables visual inspection of the interior regions of the concrete member which is also related to strength estimation.

How many concrete cores are needed for strength test?

At least three cores must be removed at each location in the structure for strength determination. The hole drilled to take the core is filled by packaged repair material. A thixotropic material is required for repair of slabs as it must not fall down under gravity.

How is core strength affected by concrete orientation?

Core strength is also affected by core orientation relative to the horizontal plane of the concrete as placed, with strength tending to be lower when measured parallel to the horizontal plane. 3 These factors shall be considered in planning the locations for obtaining concrete samples and in comparing strength test results.

Can a concrete core be tested before capping?

A core having a maximum length of less than 95% of its diameter before capping or a length less than its diameter after capping or end grinding shall not be tested. Before testing, measure the average length of the capped or ground specimen and use this length to compute L/D ratio.