Changes in the Fracture Toughness under Mode II Loading of Low Calcium Fly Ash (LCFA) Concrete Depending on Ages
This study investigated the influence of the curing time on the fracture toughness of concrete produced with different content of low calcium fly ash (LCFA). During the study, the amounts of 20% and 30% of pozzolanic additive were used. In order to observe the effect of the applied pozzolanic additi...
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MDPI AG
2020-11-01
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| Series: | Materials |
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| Online Access: | https://www.mdpi.com/1996-1944/13/22/5241 |
| _version_ | 1797547371808161792 |
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| author | Grzegorz Ludwik Golewski |
| author_facet | Grzegorz Ludwik Golewski |
| author_sort | Grzegorz Ludwik Golewski |
| collection | DOAJ |
| description | This study investigated the influence of the curing time on the fracture toughness of concrete produced with different content of low calcium fly ash (LCFA). During the study, the amounts of 20% and 30% of pozzolanic additive were used. In order to observe the effect of the applied pozzolanic additive on the analyzed concrete properties, the obtained results were compared with the values obtained for the reference concrete. Compressive strength—<i>f</i><sub>cm</sub> and fracture toughness, by using mode II loading—<i>K</i><sub>IIc</sub> (shearing), were determined between the 3rd and 365th days of curing. In the course of experiments, changes in the development of cracks in individual series of concrete were also analyzed. In addition, the microstructures of all composites and the nature of macroscopic crack propagation in mature concretes were assessed. It was observed that the greatest increase in fracture toughness at shear was in the case of reference concrete during the first 28 days, whereas, in the case of concretes containing LCFA, in the period of time above 4 weeks. Furthermore, concrete without the LCFA additives were characterized by a brittle fracture. In contrast to it, concretes with LCFA additives are mainly characterized by a quasi-plastic process of failure. Moreover, most of the samples showed a typical pattern of the destruction that occurs as a result of shearing. The presented test results may be helpful in selecting the composition of concrete mixtures containing LCFA to be used in concrete and reinforced concrete structures subjected to shear loads. |
| first_indexed | 2024-03-10T14:43:17Z |
| format | Article |
| id | doaj.art-c7d9f7fd1d374e948945701cda9d6e26 |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T14:43:17Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-c7d9f7fd1d374e948945701cda9d6e262023-11-20T21:37:20ZengMDPI AGMaterials1996-19442020-11-011322524110.3390/ma13225241Changes in the Fracture Toughness under Mode II Loading of Low Calcium Fly Ash (LCFA) Concrete Depending on AgesGrzegorz Ludwik Golewski0Department of Structural Engineering, Faculty of Civil Engineering and Architecture, Lublin University of Technology, Nadbystrzycka 40 str., 20-618 Lublin, PolandThis study investigated the influence of the curing time on the fracture toughness of concrete produced with different content of low calcium fly ash (LCFA). During the study, the amounts of 20% and 30% of pozzolanic additive were used. In order to observe the effect of the applied pozzolanic additive on the analyzed concrete properties, the obtained results were compared with the values obtained for the reference concrete. Compressive strength—<i>f</i><sub>cm</sub> and fracture toughness, by using mode II loading—<i>K</i><sub>IIc</sub> (shearing), were determined between the 3rd and 365th days of curing. In the course of experiments, changes in the development of cracks in individual series of concrete were also analyzed. In addition, the microstructures of all composites and the nature of macroscopic crack propagation in mature concretes were assessed. It was observed that the greatest increase in fracture toughness at shear was in the case of reference concrete during the first 28 days, whereas, in the case of concretes containing LCFA, in the period of time above 4 weeks. Furthermore, concrete without the LCFA additives were characterized by a brittle fracture. In contrast to it, concretes with LCFA additives are mainly characterized by a quasi-plastic process of failure. Moreover, most of the samples showed a typical pattern of the destruction that occurs as a result of shearing. The presented test results may be helpful in selecting the composition of concrete mixtures containing LCFA to be used in concrete and reinforced concrete structures subjected to shear loads.https://www.mdpi.com/1996-1944/13/22/5241concrete compositelow calcium fly ash (LCFA)curing timecompressive strengthfracture toughnessmode II loading |
| spellingShingle | Grzegorz Ludwik Golewski Changes in the Fracture Toughness under Mode II Loading of Low Calcium Fly Ash (LCFA) Concrete Depending on Ages Materials concrete composite low calcium fly ash (LCFA) curing time compressive strength fracture toughness mode II loading |
| title | Changes in the Fracture Toughness under Mode II Loading of Low Calcium Fly Ash (LCFA) Concrete Depending on Ages |
| title_full | Changes in the Fracture Toughness under Mode II Loading of Low Calcium Fly Ash (LCFA) Concrete Depending on Ages |
| title_fullStr | Changes in the Fracture Toughness under Mode II Loading of Low Calcium Fly Ash (LCFA) Concrete Depending on Ages |
| title_full_unstemmed | Changes in the Fracture Toughness under Mode II Loading of Low Calcium Fly Ash (LCFA) Concrete Depending on Ages |
| title_short | Changes in the Fracture Toughness under Mode II Loading of Low Calcium Fly Ash (LCFA) Concrete Depending on Ages |
| title_sort | changes in the fracture toughness under mode ii loading of low calcium fly ash lcfa concrete depending on ages |
| topic | concrete composite low calcium fly ash (LCFA) curing time compressive strength fracture toughness mode II loading |
| url | https://www.mdpi.com/1996-1944/13/22/5241 |
| work_keys_str_mv | AT grzegorzludwikgolewski changesinthefracturetoughnessundermodeiiloadingoflowcalciumflyashlcfaconcretedependingonages |