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Stochastic identity of test result series of the compressive strength of concrete in industrial production conditions

Jasiczak J., Kanoniczak M., Smaga Ł.

Archives of Civil and Mechanical Engineering

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2015

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Vol. 15, no. 2

584--592

EN

The article provides the scientific basis of interval identity of the compressive strength of concrete, as well as includes calculation examples concerning the application of concrete apron paving with the use of concrete pavers. It was found that in order to control the compressive strength of concrete formed in a continuous, cyclically repetitive mode, standard statistical assessment of concrete strength is not sufficient since, in the case of deviations in the studied characteristics of concrete from the project assumptions, it is not possible either to implement corrections in the concrete manufacturing process or to change the location of the concrete structure with decreased strength parameters. Due to this, the analysis of the qualitative and quantitative production of concrete mix and its application at the construction site required the use of appropriate calculation procedures, allowing to extract subsets of the results of the compressive strength of concrete projecting technological disturbances and assign to them time intervals, in which the disturbances occurred. This is a completely different approach to the issue of determining the compressive strength properties of tested concrete volume than presented in the construction standards. For this reason, to present the real picture of the compressive strength variability, the division of tests results was made by grouping the data belonging to one population with probabilistically stabilized strength parameters forming a family of concrete. In order to do this it was necessary to use appropriate calculation procedures based on verification of statistical hypotheses. The authors proposed three independent methods based on statistical tests: Pearson χ2 test, t-Student's test and Mann–Whitney's U test. The results series were divided into families of concretes and were given different sensitivity of each method. However, the breakdown of the whole series achieved by the three methods is comparable and occurred in the areas of high variability of strength.

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Normowe pojęcie rodzina betonów na przykładzie ciągłej produkcji płyt Spiroll

Jasiczak J., Kanoniczak M., Smaga Ł

Budownictwo i Architektura

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2014

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Vol. 13, nr 2

99--108

PL

W artykule przedstawiono podział na rodziny betonów ciągu wyników badan wytrzymałości betonu na ściskanie przy ciągłej produkcji mieszanki betonowej na potrzeby wytwarzania prefabrykowanych płyt stropowych w technologii Spiroll. W oparciu o procedurę obliczeniową, polegającą na weryfikacji założonych hipotez statystycznych, dokonano rozdziału zbioru wyników reprezentującego wytrzymałość po 1 oraz po 28 dniach dojrzewania. Uzyskano rodziny betonów reprezentujące statystyczną niezmienność parametrów wytrzymałościowych betonu wyprodukowanego w określonym przedziale czasu.

EN

The article presents the division of test results series for the compressive strength of concrete into concrete families for the continuous production of concrete mix used for the manufacture of precast concrete slabs in Spiroll technology. On the basis of a calculation procedure involving the verification of assumed statistical hypotheses, the division of a set of concrete strength results achieved after 1 and 28 days of curing was made. Concrete families were obtained representing the statistical invariability of strength parameters for the concrete manufactured in a defined period of time.

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Rodzina betonów - geneza pojęcia, terminologia, kryteria, ogólne zasady kreacji

Kohutek Z. B.

Przegląd Budowlany

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2010

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R. 81, nr 10

26-31

PL

W roku 2003 opublikowano normę europejską dla betonu w języku polskim, nadając jej symbol PN-EN 206-1 i tytuł "Beton - cz. 1: Wymagania, właściwości, produkcja i zgodność". W porównaniu do rozwiązań normalizacyjnych poprzedniej generacji (norma PN-88/B-06250 "Beton zwykły" ) kładzie ona nacisk m.in. na ochronę strukturalną betonu w konstrukcji przed agresją ze strony środowiska, rewolucjonizując w ten sposób podejście do kwestii trwałości materiału.

EN

In 2003 a European standard for concrete was published in Polish under the reference number PN-EN 206-1, with the title "Concrete - part 1: Requirements, properties, production and compliance". Compared with the previous generation of standard requirements (the PN-88/B-06250 standard "Ordinary concrete") it places emphasis on such matters as the structural protection of concrete against environmental factors, thus revolutionizing the approach taken to the question of durability of the material.