Dear Zaid:

The core test is reliable, but care must be taken to obtain samples without damaging the concrete. Please see the following paper:

https://www.concrete.org/publications/internationalconcreteabstractsportal/m/details/id/12283

I hope that this helps you.

Sincerely,

Arturo

Dear Zaid:

The core test is reliable, but care must be taken to obtain samples without damaging the concrete. Please see the following paper:

https://www.concrete.org/publications/internationalconcreteabstractsportal/m/details/id/12283

I hope that this helps you.

Sincerely,

Arturo

Most standards adopt it.

Yes, for further quarry pl see these research materials:

1. IS 516 " METHODS OF TESTS FOR STRENGTH OF CONCRETE "

2. Article Reliability of core test – Critical assessment and proposed ...

thank you for this paper Dr. Kundan

I agree with Dr. Arturo E Schultz. Additionally, lock for ASTM C42 for more information.

Interesting.

thank you dr. Arturo E Schultz , dr Mohannad Husain Al-Sherrawi ,. dr. Mohammed Salah Nasr and dr. Ahmed Mahdi

There is no 100% guarantee but may considered as indicator to show the status of concrete.

I agree with the answers of my colleagues

Dear Dr. Zaid

Concrete cores may be good indicator to estimate the compressive strength of concrete members when the following conditions are achieved

1- the core must extracted from a plain concrete zone (i.e. no reinforcing steel bars are faced during core extracting process)

2- the thickness of tested concrete member should be enough to provide core length/diameter ratio of about 2.0

3- core sampler should be in a good status (preferable new) and rotating speed should be according to the standards

4- core capping should be follow the ASTM standrad C42.

Regards.

thank you Dr. Alaa Hussein Al-Zuhairi

Dear Dr Zaid, is it not better to use Rebounce harmmer test instead of cure test since the essence to obtain the strength of the concrete

Thanks to all

Very useful and valuable discussion.

thanks to all

Dear Zaid Abdul Zahra Mahdi: The compressive strength of the concrete core also depends on the core diameter. I recommend you to check the following paper. The reference is written in Spanish but it is easy to follow the main results in the figures and equations. Article Incidencia del diámetro de extracción de núcleos de concreto...

thank you Dr. Julian

Dear Zaid Abdul Zahra Mahd : Core tests is probable one of the most common and accepted ways to estimate compression strength of existing RC structures by some modern seismic design/Assessment codes and standards (e.g. ACI 301, ACI 318, Eurocode 2, among others). Accordingly, they must be reliable. Nevertheless, there are Multiple parameters which could affect core test results (e.g. Moisture, geometry, embedded pieces of reinforcing steel, ...) and therefore the related results require a thoroughly analysis of envolved engineers, and cause that standard cylinder test results must not be compared directly with core test results.

In conclussion: "Core test results are reliable to estimate compression strength of existing RC structures, however special attention must paid to the analysis of results because standard cylinder test results must not be compared directly with core test results in many cases"

References:

Neville, A. (2006). Neville on Concrete: An Examination of Issues in Practice. BookSurge LLC, USA.

Hermida, G. (2006). Ensayo de Núcleos: Fácil de hacer, difícil de interpretar. ACI Revista Técnica N. 6, COLOMBIA.

European Standard BS EN 12504-1:2000, “Testing Concrete in

Structures - Part 1: Cored Specimens

British Standard Institution, BS 6089:1981, “Guide to Assessment

of Concrete Strength in Existing Structures

dear dr. Sergio

its useful answer, thank you so much

Dear Mr. Zaid,

Core testing represents the most reliable method of establishing in-situ concrete strength.

Article Reliability of core test – Critical assessment and proposed ...

thank you Mr Saad for useful answer

Very useful and valuable discussion.