Wyniki wyszukiwania - BazTech

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Właściwości kruszywa otrzymanego z wapienia pobranego selektywnie ze złoża Trzuskawica

Chełmecki D., Rembiś M., Łagosz A.

Mosty

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2018

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nr 5

46--48

PL

Niniejszy artykuł poświęcono ocenie właściwości kruszywa wapiennego wyprodukowanego w zakładzie Trzuskawica z selektywnie pozyskanego złoża.

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Properties of coarse mineral aggregates against properties of concrete

Piasta W., Budzyński W., Góra J.

Architecture Civil Engineering Environment

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2018

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Vol. 11, no. 3

97--105

EN

The paper concerns the effect of coarse aggregate type on the strength and strain properties of concrete under instantaneous loading. The studies deal with properties of the crushed aggregates and their effect on the basic mechanical properties and instant deformability of concretes in comparison to gravel concrete. The paper presents test results of mineral composition, crushing strength, absorption by weight, content of irregular grains and mineral dust as well as bulk and specific density of the 5 coarse aggregates: basalt, granite, dolomite, quartzite and natural aggregate (gravel) derived from the Polish rock beds. Strength and strain properties of concretes under compressive instantaneous loading were analyzed. The analysis showed that strength properties and modules of elasticity of tested concretes are proportional to crushing strength of aggregates. Based on the test results of strains it was concluded that the effect of coarse aggregate type on the modulus of elasticity and the limit strain is more significant than that of concrete strength.

3

Badania wybranych właściwości kruszyw z odpadów ceramicznych oraz betonu wytworzonego z ich udziałem

Gawenda T., Naziemiec Z., Walerak A.

Rocznik Ochrona Środowiska

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2013

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Tom 15, cz. 3

2003--2021

EN

The aim of the paper was to present the possibilities of ceramic waste utilization towards the artificial aggregaters and concretes production. The investigations covered the waste comminution experiments at AGH in two-stage circuits with jaw and roll crushers, and particle size analyses. Experiments in ICMB Institute in Cracow included a determination of the water absorption index, comminution resistance and frost-resistance coefficients, as well as the bulk density. Two types of concretes were compared, the one produced with the participation of ceramic waste, and the other, produced from Devonian limestone. The aggregates produced from ceramic waste had an unfavorable particle shape. Jaw crushers on the first and second stage produced 63 and 22% of irregular particles respectively, while the roll crusher on second stage only 14%. The plant production aggregates from the waste should therefore be based on a closed multi-stage crushing and classification circuits with processing of aggregates. Ceramic waste crushing should be performed in devices producing cubical products, like impacrtors. These methods allow to obtain the aggregates with the smallest flatness indices and without pollution. The high water absorption, lower comminution and frost resistance of concretes are further unfavorable properties of aggregates produced from the ceramic waste. Unfavorable rheological properties of the concrete mixtures, resulting from the impact of the aggregate disadvantages can be improved by the use of hydrophobic additives which reduce the water absorption, thereby increasing water resistance of concrete. Artificial aggregate concrete had a lower compressive strength (about 33 MPa) than the natural concrete (about 49 MPa). Decrease in compressive strength of the artificial aggregate concrete subjected to freezing and defrosting cycles was 18.3%, which is a relatively high and negative. Summing up, the ceramic waste after a prior processing can be applied in the building industry. After a precise examination of the properties of artificial aggregates and application of suitable additives, they can be alternatively used in concrete production, particularly under conditions in which there is no impact of temperatures below zero degrees.

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Norma 933-8 Badanie wskaźnika piaskowego – mała norma – wielka zmiana

Krajewski M.

Nawierzchnie Asfaltowe

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2013

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Nr 4

10--12

PL

Zgodnie z informacją zamieszczoną na stronie Polskiego Komitetu Normalizacyjnego (PKN) 19.03.2012 r. nastąpiła cicha prapremiera normy PN-EN 933-8: 2012E Badania geometrycznych właściwości kruszyw – Część 8: Ocena zawartości drobnych cząstek – Badanie wskaźnika piaskowego. Wcześniejsze odsłony tej normy, tj. PN-EN 933-8:2001P i dodatku PN-EN 933-8:2001/Ap1:2010P1, zostały wycofane ze zbioru polskich norm i oficjalnie zastąpione nowym dokumentem, który obowiązuje przy badaniu wskaźnika piaskowego.