Determination of a Suitable Moment for Formwork Removal from a Concrete Structure Using Rebound Hammer Test Methods

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26110%2F21%3APU141331" target="_blank" >RIV/00216305:26110/21:PU141331 - isvavai.cz</a>

Result on the web

<a href="https://www.scientific.net/SSP.322.23" target="_blank" >https://www.scientific.net/SSP.322.23</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4028/www.scientific.net/SSP.322.23" target="_blank" >10.4028/www.scientific.net/SSP.322.23</a>

Result language

angličtina

Original language name

Determination of a Suitable Moment for Formwork Removal from a Concrete Structure Using Rebound Hammer Test Methods

Original language description

Determining the compressive strength of concrete in the early stages of ageing has been an increasingly relevant topic in recent years, particularly with regard to safe removal of formwork from a structure or its part. The compressive strength of concrete which designates safe removal of formwork without damaging the structure can be referred to as ”stripping strength”. It is undoubtedly beneficial to be able to determine the moment of safe formwork removal in a non-destructive manner, i.e. without compromising the structure. Modern rebound hammer test methods seem to be a suitable instrument with which it is possible to reduce the length of technological breaks associated with concrete ageing to a minimum, and consequently, reduce the total cost of the construction. However, the use of these methods presents a number of challenges. As many conducted experiments have shown, there is no single conversion relationship (regression model) between non-destructive rebound hammer test methods and compressive strength. It is therefore advisable to always create a unique conversion relationship for each individual concrete. In addition, it must be noted that conventional regression analysis methods operate with 50% reliability. In construction testing, however, the most common is the so-called characteristic value, which is defined as a 5% quantile. This value is therefore determined with 95% reliability. This paper describes the construction of a so-called ”characteristic curve”, which can be used to estimate the compressive strength of concrete in a structure using rebound hammer test methods with 95% reliability. Consequently, the values obtained from the characteristic curve can be easily used for practical applications.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

20101 - Civil engineering

Project

<a href="/en/project/GA19-22708S" target="_blank" >GA19-22708S: New approaches to predicting air-entrained concrete durability by means of determination of pore size distribution and freeze-thaw resistance</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

27th Concrete Days

ISBN

978-3-0357-1821-8

ISSN

1662-9779

e-ISSN

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Number of pages

5

Pages from-to

23-27

Publisher name

Trans Tech Publications Ltd

Place of publication

Switzerland

Event location

Praha

Event date

Dec 2, 2020

Type of event by nationality

CST - Celostátní akce

UT code for WoS article

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