Petr Hajek

Prof. Dr. Petr Hajek

Czech Technical University in Prague, Faculty of Civil Engineering
+1
orcid

Research Focus & Metrics

Academic Career Length

36Years (1991-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 November 2016 in Construction and Building Materials
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Journal Article
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Anuj KumarAnuj Kumar
Anuj Kumar
TVTomáš Vlach
Tomáš Vlach
LLLenka Laiblova
Lenka Laiblova
MHMartin Hrouda
Martin Hrouda
Bohumil KasalBohumil Kasal
Bohumil Kasal
Petr HajekPetr Hajek
Petr Hajek

10 March 2011 in Structural Concrete
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Petr HajekPetr Hajek
Petr Hajek
CFCtislav Fiala
Ctislav Fiala
MKMagdaléna Kynčlová
Magdaléna Kynčlová

29 September 2019 in Materials
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Lenka IngrisovaLenka Ingrisova
Lenka Ingrisova
JPJan Pešta
Jan Pešta
Anuj KumarAnuj Kumar
Anuj Kumar
Petr HajekPetr Hajek
Petr Hajek
CFCtislav Fiala
Ctislav Fiala
Vladimír KočíVladimír Kočí
Vladimír Kočí
Pitch-faced concrete is becoming a very popular element of modern architecture in the 21st century. In particular, the demand for concrete facades is increasing globally. On the other hand, climate change, environmental degradation, and limited resources are motivations for sustainable building materials. The construction industry is one the highest emitters of CO2 and other greenhouse gases, in which concrete plays a major role. Thus, reduction in the volume of concrete consumption is essential to control greenhouse gases. One approach to this problem is to use textile reinforced concrete (TRC). The main aim of the present study was to compare the subtle TRC facade made of three different types of technical textile rovings (glass, carbon, and basalt) with ordinary facades reinforced by steel reinforcement (ORC). The goal was to compare the basic environmental impact potential according to product category rules (PCR) for concrete structures. The functional unit was defined as an experimental facade with an area of 60 m2 and a 100-year lifespan. Inventory data were elaborated for concrete, steel, and textile fiber production; the building site; service life; demolition; and final disposal. The main life cycle assessment (LCA) parameters were global warming potential (GWP), ozone depletion (ODP), acidification (AP), eutrophication (EP), abiotic depletion (ADP), and photochemical oxidant creation (POCP). All the data used in the work were related to Czech Republic. Textile reinforced concrete facades appeared to be more environmentally friendly in four of six impact categories by an average of 30%. The results of the present study revealed that, in comparison to ORC, TRC has a lower environmental impact for the given conditions and thus good potential for use in sustainable construction.

1 December 2016 in Composites Part B: Engineering
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Anuj KumarAnuj Kumar
Anuj Kumar
KSKamil Staněk
Kamil Staněk
PRPavla Ryparová
Pavla Ryparová
Petr HajekPetr Hajek
Petr Hajek
JTJan Tywoniak
Jan Tywoniak

5 November 2019 in Sustainability
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TPTereza Pavlů
Tereza Pavlů
Vladimír KočíVladimír Kočí
Vladimír Kočí
Petr HajekPetr Hajek
Petr Hajek
The main goal of this study was to compare two use cycles of natural aggregate concrete and recycled aggregate concrete, which is another way to compare the environmental impacts of recycled materials. A series of concrete mixtures with various replacement ratios of primary resources with recycled ones were prepared for this study. The mechanical properties of concrete mixtures were examined and were used for the design of structural elements in the same utilized properties. The two use cycles of a structural element were compared using life cycle assessment (LCA). In the first use cycle, the LCA of the structural element containing only primary raw materials was assessed. In the second use cycle, the LCA of a structural element in which primary materials were partially replaced by recycled ones was assessed. The obtained results confirm the potential use of high-quality recycled aggregate originating from local sources in some applications in building structures. Furthermore, the environmental assessment indicates the benefits of using recycled materials, such as environmental savings, especially the reduction of primary resource use, embodied energy, and embodied emissions, as well as reduction of the pressure on landfill sites.

14 June 2019 in Materials
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TPTereza Pavlů
Tereza Pavlů
KFKristina Fořtová
Kristina Fořtová
JDJakub Divis
Jakub Divis
Petr HajekPetr Hajek
Petr Hajek
The main aim of this paper is to carry out the environmentally based enhancement of a concrete mixture containing recycled materials whilst considering natural resource consumption as well as mechanical and thermal property levels. The developed concrete is intended to be used in mortarless masonry wall structures. Ten concrete mixtures with different types and replacement rates of recycled masonry aggregate and recycled expanded polystyrene were prepared, and their mechanical and thermal properties were experimentally investigated. It was found that the use of recycled masonry aggregate led to better thermal properties while maintaining sufficient mechanical properties. On the contrary, the addition of recycled expanded polystyrene did not significantly affect the thermal properties of concrete, but the mechanical properties considerably declined. For this reason, the recycled masonry aggregate is suitable to use as an aggregate for concrete masonry blocks for wall structures.