Lech Czarnecki | Institut Teknologi Bandung (original) (raw)

Papers by Lech Czarnecki

Applied sciences, Feb 15, 2019

In less than one century, concrete has become the most widely used construction material worldwid... more In less than one century, concrete has become the most widely used construction material worldwide. Today it is difficult to imagine a concrete totally without polymers. An implantation of polymers into concrete has taken effect in the form of concrete-polymer composite [C-PC = PMC + PCC + PIC + PC]. On the way of C-PC development, several milestones are recognized and discussed here with particular emphasis on innovative milestones that shaped the use of polymers in concrete. As the difference between polymer-cement concrete and ordinary concrete diminishes, the question: “Are polymers still driving forces in concrete technology?” arises. This question is about the future of the concrete technology. The authors consider various optional answers. One of the most promising options seems to be that the routes of nanotechnology and the organic-inorganic chemically bound composites will open the gate for the development of a new generation of sustainable polymer. The new polymer concret...

MATERIAŁY BUDOWLANE, 2016

Advanced Materials Research, 2013

Sustainable development as the leading civilization idea, and nanotechnology as the contemporary ... more Sustainable development as the leading civilization idea, and nanotechnology as the contemporary wave of technology significantly affecting the society, are brought together in this paper. A brief history of sustainability implementation from the start concept until European Construction Product Regulation is presented. The extended definitions of sustainable construction and sustainable material are analysed with adequate conclusions towards Concrete. The category of Exergy is implemented as a measure for “natural environmentally-friendly” meaning. The generalised concrete development curve is presented with discussion of Well Defined Concrete Performance. The statement that the sustainability is necessity for concrete and the nanotechnology is the chance for the future of concrete polymer composite is the final conclusion of the paper.

Restoration of Buildings and Monuments, 2012

Advances in Composite Materials, 1980

Brittle Matrix Composites 2, 1989

Der Beitrag stellt einige Ueberlegungen zur weiteren Entwicklung polymermodifizierten Kompositbet... more Der Beitrag stellt einige Ueberlegungen zur weiteren Entwicklung polymermodifizierten Kompositbetons an und geht auch auf die bisherige Entwicklung dieser Materialien ein. Begonnen hat diese Entwicklung mit dem nunmehr allbekannten Polymer-Cement-Concrete (PCC) oder - allgemein ausgedrueckt - den Concrete-Polymer Composites (C-PC). Es wird postuliert, dass es wohl keine vollstaendig neue Erfindungen von Materialien auf diesem Gebiet geben wird, sondern verschiedene Weiterentwicklungen. Dazu gehoert an erster Stelle die Weiterentwicklung des C-PC hin zu Sustainable Concrete-Polymer Composites (S-C-PC), also zu nachhaltigen polymer- und zementhaltigen Kompositmaterialien. Die bisherige Entwicklung von Polymer-Zement-Materialien wird im Licht der seit 1975 durchgefuehrten einschlaegigen Kongresse und Symposien der ICPIC (International Congress on Polymer in Concrete) und der ASPIC (Asian Society of Polymers in Concrete) dargestellt und anhand der bei diesen Veranstaltungen vorgestellten Themen beurteilt. Demnach sind eine nahezu stetige materialtechnologische Entwicklung und eine Verwissenschaftlichung der theoretischen Grundlagen festzustellen, die auch zeigen, dass die Behandlung der Nachhaltigkeit der Materialien in Zukunft noch staerker zunehmen wird. Grosse Fortschritte zur Klaerung des Materialverhaltens sind sowohl auf der Makroebene als auch auf der Mikroebene festzustellen. Auf der Nanoebene hat die Entwicklung gerade erst begonnen. Allgemein gehoeren zu den polymerhaltigen Betonen: Polymer Modified Concrete (PMC), Polymer-Cement Concrete (PCC), Polymer Impregnated Concrete (PIC), Polymer Concrete (PC). Will man die weitere Entwicklung voraussehen, so muss man die wirtschaftlichen Unterschiede weltweit beruecksichtigen. In Asien wird heute mehr als dreimal soviel Zement produziert als in Europa. Dort steht auch der Neubau von Bauwerken im Vordergrund, waehrend in Europa aufgrund des Alters der Infrastruktur die Erhaltung die erste Stelle einnimmt. Schwerpunkte der Weiterentwicklung werden die Dauerhaftigkeit, die Zuverlaessigkeit und die Nachhaltigkeit sein. Als Einzelaspekte spiele dabei unter anderem die Entwicklung duktilerer Materialien, verbesserte Formulierungen der Mischungen durch Kombination verschiedener Bestandteile und anwendungsfreundlichere Materialien eine Rolle. Es zeichnet sich auch eine Entwicklung zu objektbezogenen Materialentwicklungen ab, anstatt von Formulierungen, die allgemein eingesetzt werden koennen. Ein grosses Potenzial bietet die Anwendung von Nanopartikeln, wie die staendig zunehmende Zahl von Veroeffentlichungen zu dieser Thematik zeigt. Es ist bekannt, dass schon durch Zugabe von 10 Prozent Polymeren die Zugfestigkeit des Betons von 2,5 Megapascal bis auf das Vierfachen gesteigert werden kann. Forschungen zeigen, dass bei Anwendung von Nanopartikeln schon eine Zugabe von 1 Prozent solcher Partikel zum Beton eine Steigerung der Betonzugfestigkeit von bis zu 15 Megapascal ermoeglicht. ABSTRACT IN ENGLISH: The future is difficult to forecast, but forecasting is necessary, as those whose objectives are unclear do not know how to use the driving force of change for their own development. The problem arises: what does CpC for C-PC mean - Change per Continuation of Concrete-Polymer Composites? It is expected that further C-PC development will be oriented towards the transformation from C-PC to the S-C-PC, Sustainable Concrete-Polymer Composites. It is rather unlikely that we will see a completely new material in the C-PC domain. In spite of that, Well Defined Properties C-PC is expected. The family of C-PC came of age, but they are still very promising materials for new applications. They need a theoretical basis to make the improvements more efficient and reliable. Exploitation of nanosize effects and synergy is an important challenge in the future. (A)

Brittle Matrix Composites 1, 1986

Journal of Applied Polymer Science, 1980

Page 1. Shear Flow Rheological Properties, Fiber Damage, and Mastication Characteristics of Arami... more Page 1. Shear Flow Rheological Properties, Fiber Damage, and Mastication Characteristics of Aramid-, Glass-, and Cellulose-Fiber-Reinforced Polystyrene Melts LECH CZARNECKI* and JAMES L. WHITE, Polymer Engineering ...

Applied Sciences, 2019

Active fire protection systems are critical elements of good process safety. Among them, gaseous ... more Active fire protection systems are critical elements of good process safety. Among them, gaseous extinguishing systems provide quick, clean suppression and prolonged protection due to long retention process of the gas. Standard design methods do not provide sufficient tools for optimisation of the retention process, thus the necessity for development and validation of new tools and methods—such as Computational Fluid Dynamics (CFD) simulations. This paper presents a simplified approach to CFD modelling, by the omission of the discharge phase of the gas system. As the flow field after discharge is stable and driven mainly by the hydrostatic pressure difference, buoyancy and diffusion, this simplified approach appears as an efficient and cost-effective approach. This hypothesis was tested through performing CFD simulations, and their comparison against experimental measurements in a bench scale in a small compartment (0.72 m3), for six mixtures that differ in their density. Modelling ...

Archives of Civil Engineering

The paper presents pursuits of the truth in building materials engineering. Some definitions of "... more The paper presents pursuits of the truth in building materials engineering. Some definitions of "what truth is" were presented. Partial truths were specified: the truth of scientific reasoning, the truth of scientific assessment, the truth of development directions and the splendour of scientific truth. All categories are addressed to the building materials engineering. In the chapter "Load capacity and stability vs entropy" definitions of entropy and exergy were presented followed by their influence on building construction, illustrated by the "Seneca cliff" and "Energy pyramid". Chapter 3 presents the truth of scientific reasoning was presented. Three partial truths were indicated: the truth of experimental fact, the truth of scientific reasoning and the truth of scientific presentation. In the chapter "Truth of scientific assessment" two main assessment methods were presented: peer review and a bibliometric parametric assessment as well as their impact on the results and authors. The risks associated with the sole parametric assessment were shown as the two basic factors of a parametric assessment-citation number and Hirsch index-need time to "mature". Additionally, the influence of digitalisation of the assessment of a scientist and a scientific unit on the commoditisation and dehumanisation of science was outlined. In the chapter "Truth of development directions: defined past-fuzzy future" the megatrends observed in technology in the last few decades years were indicated along with new possible trends. Milestones in the development of C-PCs (Concrete-Polymer Composites) were presented. The new paradigm for the new development cycle was proposed.