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The aim of this study was to present the problem of durability of structural lightweight concrete made of a sintered fly ash aggregate. The issue of durability was researched for 12 concrete series in terms of their water absorption, water permeability, and freeze-thaw resistance. Additionally, the microstructure of several concretes was analyzed with a scanning electron microscope (SEM). In the durability research, the influences of the following parameters were taken into consideration: The initial moisture content of sintered fly ash (mc = 0, 17–18, and 24–25%); the aggregate grading (4/8 and 6/12 mm); and the water-cement ratio (w/c = 0.55 and 0.37). As a result of various compositions, the concretes revealed different properties. The density ranged from 1470 to 1920 kg/m3, and the corresponding strength ranged from 25.0 to 83.5 MPa. The durability research results of tested lightweight concretes showed that, despite considerably higher water absorption, a comparable water permeability and comparable or better freeze-thaw resistance in relation to normal-weight concrete may be present. Nevertheless, the fundamental requirement of lightweight concrete to achieve good durability requires the aggregate’s initial moisture content to be limited and a sufficiently tight cement matrix to be selected. The volume share of the cement matrix and aggregate, the cement content, and even the concrete strength are of secondary importance.
Lucyna Domagała. Durability of Structural Lightweight Concrete with Sintered Fly Ash Aggregate. Materials 2020, 13, 4565 .
AMA StyleLucyna Domagała. Durability of Structural Lightweight Concrete with Sintered Fly Ash Aggregate. Materials. 2020; 13 (20):4565.
Chicago/Turabian StyleLucyna Domagała. 2020. "Durability of Structural Lightweight Concrete with Sintered Fly Ash Aggregate." Materials 13, no. 20: 4565.
The aim of this paper is to discuss the unrecognized problem of the scale effect in compressive strength tests determined for cored specimens of lightweight aggregate concrete (LWAC) against the background of available data on the effect for normal-weight concrete (NWAC). The scale effect was analyzed taking into consideration the influence of slenderness (λ = 1.0, 1.5, 2.0) and diameter (d = 80, 100, 125, and 150 mm) of cored specimens, as well as the type of lightweight aggregate (expanded clay and sintered fly ash) and the type of cement matrix (w/c = 0.55 and 0.37). The analysis of the results for four lightweight aggregate concretes revealed no scale effect in compressive strength tests determined on cored specimens. Neither the slenderness, nor the core diameter seemed to affect the strength results. This fact should be explained by the considerably better structural homogeneity of the tested lightweight concretes in comparison to normal-weight ones. Nevertheless, there were clear differences between the results obtained on molded and cored specimens of the same shape and size.
Lucyna Domagała. Size Effect in Compressive Strength Tests of Cored Specimens of Lightweight Aggregate Concrete. Materials 2020, 13, 1187 .
AMA StyleLucyna Domagała. Size Effect in Compressive Strength Tests of Cored Specimens of Lightweight Aggregate Concrete. Materials. 2020; 13 (5):1187.
Chicago/Turabian StyleLucyna Domagała. 2020. "Size Effect in Compressive Strength Tests of Cored Specimens of Lightweight Aggregate Concrete." Materials 13, no. 5: 1187.
The aim of this paper is to assess the effect of modification of fine-aggregate concrete properties with zirconia alkali-resistant glass fibres. Three types of fine-aggregate composites were subject to tests: normal-weight concretes made of natural sand, non-foamed and foamed lightweight concretes made of expanded glass aggregate. The concretes were modified with the glass fibres mainly in quantities ranged from 1.0 to 5.0 kg/m3. Even such low contents resulted in the increase of both flexural and compressive strength, by up to 45 % and 26 %, respectively. In the case of normal-weight fine-aggregate concretes the applied glass fibres turned out to be especially effective in improvement of the properties in early ages. At the age of 28 days both types of concretes revealed similar percentage strength increase. In comparison to HP 12 mm the application of longer fibres (HP 24 mm) led to slightly higher results of flexural strength tests. On the other hand, the shorter fibres were definitely more effective in the improvement of compressive strength due to their greater number and more uniform dispersion in concrete volume. The used contents of alkali-resistant glass fibres did affect neither density nor water absorption of the hardened concretes.
Lucyna Domagała; Ewelina Bizoń-Żabińska; Kamil Kurzyniec. The influence of alkali-resistant glass fibres on properties of fine-aggregate concretes. MATEC Web of Conferences 2019, 262, 06003 .
AMA StyleLucyna Domagała, Ewelina Bizoń-Żabińska, Kamil Kurzyniec. The influence of alkali-resistant glass fibres on properties of fine-aggregate concretes. MATEC Web of Conferences. 2019; 262 ():06003.
Chicago/Turabian StyleLucyna Domagała; Ewelina Bizoń-Żabińska; Kamil Kurzyniec. 2019. "The influence of alkali-resistant glass fibres on properties of fine-aggregate concretes." MATEC Web of Conferences 262, no. : 06003.
The aim of this paper is to assess durability of concretes made of expanded glass, perlite and polystyrene aggregates exposed to high temperature. The following tests of four concretes, used in practice for insulating-structural applications, were carried out: density in saturated, natural and oven-dry state, compressive and flexural strength at the curing temperature and after heating at the temperature of 100 oC, 200 oC, 300 oC and 400 oC. The tests results showed that applied high temperatures affected the properties of concretes in different way depending on their compositions. Nevertheless, all four composites retained sufficient strength to be still regarded as insulating-structural concretes.
Lucyna Domagała. Resistance of insulating-structural concretes to high temperature. Procedia Structural Integrity 2019, 23, 342 -347.
AMA StyleLucyna Domagała. Resistance of insulating-structural concretes to high temperature. Procedia Structural Integrity. 2019; 23 ():342-347.
Chicago/Turabian StyleLucyna Domagała. 2019. "Resistance of insulating-structural concretes to high temperature." Procedia Structural Integrity 23, no. : 342-347.
The paper presents the results of tests conducted on two lightweight aggregate concretes made of new national Certyd artificial aggregate. This research is intended to first application of lightweight concrete to construct large-span post-tensioned slab. In addition to mechanical properties development, shrinkage and creep during 3 months of loading were tested. The obtained results are compared with theoretical results predicted by standard. Conducted tests indicated, that measured values of shrinkage and creep are significantly lower than predicted ones. This is promise for application of tested concrete in construction of post-tensioned slabs.
Małgorzata Mieszczak; Lucyna Domagała. Lightweight Aggregate Concrete as an Alternative for Dense Concrete in Post-Tensioned Concrete Slab. Materials Science Forum 2018, 926, 140 -145.
AMA StyleMałgorzata Mieszczak, Lucyna Domagała. Lightweight Aggregate Concrete as an Alternative for Dense Concrete in Post-Tensioned Concrete Slab. Materials Science Forum. 2018; 926 ():140-145.
Chicago/Turabian StyleMałgorzata Mieszczak; Lucyna Domagała. 2018. "Lightweight Aggregate Concrete as an Alternative for Dense Concrete in Post-Tensioned Concrete Slab." Materials Science Forum 926, no. : 140-145.
The paper focuses on the influence of the standard test method applied to determine the concrete stabilized secant modulus on a specified value. The new European Standard EN 12390-13 for testing hardened concrete accepts two methods (A and B) for the determination of the secant modulus of elasticity in compression. The aim of the research was to establish how different testing procedures affect a measured value of modulus of elasticity. Four structural concrete series: two lightweight aggregate concretes and two normal-weight ones were subject to tests of moduli of elasticity determined by both standard methods, as well as compressive strength and density. The carried out tests revealed that the procedure of testing modulus of elasticity influenced a measured value. Method A led to higher values of modulus in relation to Method B, irrespective of concrete density and strength. Nevertheless, a certain relationship between the concrete structure homogeneity and the difference in results of moduli determined by both methods may be observed.
Lucyna Domagała; Justyna Dobrowolska. The influence of an applied standard test method on a measurement of concrete stabilized secant modulus of elasticity. MATEC Web of Conferences 2018, 163, 07001 .
AMA StyleLucyna Domagała, Justyna Dobrowolska. The influence of an applied standard test method on a measurement of concrete stabilized secant modulus of elasticity. MATEC Web of Conferences. 2018; 163 ():07001.
Chicago/Turabian StyleLucyna Domagała; Justyna Dobrowolska. 2018. "The influence of an applied standard test method on a measurement of concrete stabilized secant modulus of elasticity." MATEC Web of Conferences 163, no. : 07001.
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Lucyna Domagała. Wpływ naprężeń ściskających wg PN-EN 12390-13 oraz PN-EN 1992-1-1 na wynik oznaczenia modułu sprężystości betonu. MATERIAŁY BUDOWLANE 2017, 1, 57 -61.
AMA StyleLucyna Domagała. Wpływ naprężeń ściskających wg PN-EN 12390-13 oraz PN-EN 1992-1-1 na wynik oznaczenia modułu sprężystości betonu. MATERIAŁY BUDOWLANE. 2017; 1 (8):57-61.
Chicago/Turabian StyleLucyna Domagała. 2017. "Wpływ naprężeń ściskających wg PN-EN 12390-13 oraz PN-EN 1992-1-1 na wynik oznaczenia modułu sprężystości betonu." MATERIAŁY BUDOWLANE 1, no. 8: 57-61.
The paper focuses on the influence of concrete type and strength on the relationship between initial and stabilized secant moduli of elasticity. These moduli, as well as compressive strength and density, were tested for four structural concrete series: two lightweight aggregate and two normal-weight ones. The carried out research showed that in each case the value of initial secant modulus of elasticity was lower than the stabilised one and the ratio of these two moduli is strongly dependent on concrete material homogeneity.
Lucyna Domagała. A Study on the Influence of Concrete Type and Strength on the Relationship between Initial and Stabilized Secant Moduli of Elasticity. Solid State Phenomena 2016, 258, 566 -569.
AMA StyleLucyna Domagała. A Study on the Influence of Concrete Type and Strength on the Relationship between Initial and Stabilized Secant Moduli of Elasticity. Solid State Phenomena. 2016; 258 ():566-569.
Chicago/Turabian StyleLucyna Domagała. 2016. "A Study on the Influence of Concrete Type and Strength on the Relationship between Initial and Stabilized Secant Moduli of Elasticity." Solid State Phenomena 258, no. : 566-569.
The aim of this paper is to present the problem of water-cement ratio reduction in structural lightweight concrete as a result of mixing water absorption by the lightweight aggregate. The research was carried out on eighteen concrete mixtures made of sintered fly ash aggregate and cement pastes of different nominal water-cement ratios. It has been demonstrated that the rate and the extent of the absorption of mixing water by the aggregate in concrete is dependent not only on its water absorption, but also on its moisture content, moisture state, the procedure of concrete preparation and the concrete composition. Moreover, it has been proved that the standard method for calculation of the so-called effective water-cement ratio is accurate only in the case of high initial moisture content of the lightweight aggregate. When dry sintered fly ash aggregate is used, the standard method gives underestimated values of the ratio as compared to its actual values determined in tests.The effect of mixing water absorption by the lightweight aggregate, revealed in tests of fresh concrete as the reduction of water-cement ratio, was also reflected in hardened state of concrete as the increase of its strength. The strength increase was higher for mixtures with higher content of lightweight aggregate. Although the porous aggregate is the weakest element in structural lightweight concrete, in this case its higher content may be compensated with excess by the stronger cement matrix resulting from the reduction of water-cement ratio
Lucyna Domagała. The Effect of Lightweight Aggregate Water Absorption on the Reduction of Water-cement Ratio in Fresh Concrete. Procedia Engineering 2015, 108, 206 -213.
AMA StyleLucyna Domagała. The Effect of Lightweight Aggregate Water Absorption on the Reduction of Water-cement Ratio in Fresh Concrete. Procedia Engineering. 2015; 108 ():206-213.
Chicago/Turabian StyleLucyna Domagała. 2015. "The Effect of Lightweight Aggregate Water Absorption on the Reduction of Water-cement Ratio in Fresh Concrete." Procedia Engineering 108, no. : 206-213.
Structural lightweight aggregate concrete (SLWAC) is an alternative building material to normal-weight one, due to its ability to reach a relatively high compressive strength at still significantly lower density. Nevertheless, the application of lightweight aggregate instead of normal-weight one to concrete must result in deterioration of some characteristics of the composite. One of the methods of improving SLWAC properties is incorporation of fibers into concrete. This paper focuses on the influence of steel fibres on modification of properties of structural lightweight concrete with sintered fly ash aggregate. Two different concrete mixtures, producing various levels of matured composite density and compressive strength, were modified with three dosages of fibers: 30, 45 and 60 kg/m3. The applied amounts did not result in significant deterioration of the rheological parameters of concrete mixtures. Despite relatively low volume content of fibres, a considerable increase of flexural and tensile splitting strength was observed. Fibres also improved concrete shrinkage as well as post-peak deformability in uni-axial compression. The effect of steel addition on compressive strength proved to be dependent on specimen type. Nevertheless, it was not as crucial as in the case of the above characteristics. However, the modulus of elasticity of SLWAC was not affected by fibre addition. Santrauka Konstrukcinis su lengvaisiais užpildais betonas (SLWAC) yra normalaus svorio statybinių medžiagų alternatyva, turinti mažesnį tankį ir gebėjimą pasiekti gana didelį gniuždomąjį stiprį. Nepaisant to, lengvieji užpildai, naudojami vietoj normalaus svorio užpildų, realiai gali pabloginti kai kurias kompozito savybes. Vienas iš lengvojo betono SLWAC savybių tobulinimo būdų yra plieninių fibrų įterpimas į betono sudėtį. Šiame darbe aptariamas plieninių fibrų poveikis konstrukcinio lengvojo betono su lakiaisiais pelenais savybėms. Tikslui pasiekti buvo parinktos pagal tankį ir gniuždomąjį stiprį dvi skirtingos betono sudėtys su skirtingais (30, 45 ir 60 kg/m3) plieninių fibrų tankiais. Paruošti bandiniai buvo naudoti gniuždomajam stipriui ir kitoms savybėms nustatyti. Tyrimų rezultatai parodė, kad plieninių fibrų priedas nepablogino reologinių betono mišinio rodiklių. Nepaisant palyginti mažo fibrų kiekio, labai padidėjo bandinių lenkiamasis ir tempiamasis stipris. Fibros taip pat pagerino deformacines betono savybes. Gauto kompozito gniuždomasis stipris iš dalies priklausė nuo naudojamų plieninių fibrų charakteristikų. Tačiau plieninių fibrų priedas nepakeitė SLWAC tamprumo modulio.
Lucyna Domagała. MODIFICATION OF PROPERTIES OF STRUCTURAL LIGHTWEIGHT CONCRETE WITH STEEL FIBRES / LENGVOJO BETONO SAVYBIŲ MODIFIKAVIMAS PLIENINĖMIS FIBROMIS. JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 2011, 17, 36 -44.
AMA StyleLucyna Domagała. MODIFICATION OF PROPERTIES OF STRUCTURAL LIGHTWEIGHT CONCRETE WITH STEEL FIBRES / LENGVOJO BETONO SAVYBIŲ MODIFIKAVIMAS PLIENINĖMIS FIBROMIS. JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT. 2011; 17 (1):36-44.
Chicago/Turabian StyleLucyna Domagała. 2011. "MODIFICATION OF PROPERTIES OF STRUCTURAL LIGHTWEIGHT CONCRETE WITH STEEL FIBRES / LENGVOJO BETONO SAVYBIŲ MODIFIKAVIMAS PLIENINĖMIS FIBROMIS." JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 17, no. 1: 36-44.