How models can make a difference for a sustainable future of the building industry

Models play a vital role in science and technology and in the evolution of modern societies. They are used for describing processes and mechanisms, experimental observations, analyses and predictions. In spite of the fact that models are a reduction of reality, the achievements of modern societies are impressive and would have been inconceivable without the role of models. These achievements can be qualified with one term: growth. The impressive growth in past decades, however, now appears to be unsustainable. In this contribution the above-mentioned dilemma is dealt with. First the evolution and use of models is discussed from a more general sustainability perspective. In the second part of the paper the application of models for sustainable solutions in the field of cementitious materials is emphasized.Materials and Environmen

Numerical Simulation of Hydration and Microstructural Development in Hardening Cement-Based Materials

Design & ConstructionCivil Engineering and Geoscience

Artificial cooling of hardening concrete

In this study the tools and ingredients have been discussed withwhich the complicated subject could be managed. For this purposesome new conceptions have been introduced and incorporated in a modelin such a way that, in principle, the model is ready for fitting inappropriate computer programs. No doubt, improvements and extentionsof the model are either possible, desirable or required. Nevertheless, the results of and recommendations stated in this study are thoughtworth considering and may contribute to a better insight in thiscomplicated subject.Design & ConstructionCivil Engineering and Geoscience

Relaxation of young concrete

In the report lying in front of you it is endeavoured to come to qualitative and quantitative pronouncements with regard to the rheological behaviour of hardening cement based materials.Design & ConstructionCivil Engineering and Geoscience

Simulation of hydration and formation of structure in hardening cement-based materials

Second edition

Simulation of hydration and formation of structure in hardening cement-based materials

Civil Engineering and Geoscience

Het model: vehikel voor glorie en schade

AfscheidsredeMaterials and Environmen

A critical appraisal of codes as vehicles for realising on-site quality

The increasing demand for quality, durability and sustainability requires a critical evaluation of currently used building codes. Although there is no doubt that we need codes, standards, certificates etc., the existence of these documents are no guarantee that the prescribed quality is realized on the building site. In this paper the essential ingredients for ensuring that the required quality and performance of a structure is realized will be discussed. The responsibility issue will be addressed, as well as a number of other parameters of which the relation with quality is undeniable, but which are still difficult to quantify. The role of simulation and predictive models and the potential of serious gaming in view of achieving quality goals will be addressed. It will be emphasized that neither codes nor models can replace the responsibility of individuals for the required quality. With respect to the role of codes and models it is remarked that overestimating them may result in unjustified expectations about the performance of a material or structure. Underestimating the role of these tools may lead to scepticism and in the end unjustified negative judgment of the role science may have for enhancing the quality of the built environment.Structural EngineeringCivil Engineering and Geoscience

Societal Burden and Engineering Challenges of Ageing Infrastructure

Ageing is an inherent feature of nature and, hence, of materials, structures and systems. Yet, it seems a rather new topic in both science and engineering. The main reason for increasing attention for ageing as a topic is the growing awareness that, particularly in industrialized countries, ageing of our assets is a financial burden for the society. It touches our environment and a country's economy. It affects the overall sustainability of our planet and deserves, therefore, our utmost attention. In this contribution the urgency and challenges of ageing of concrete structures are addressed. Recent estimates of the extent of the issue and how ageing problems are dealt with in different disciplines, reactive or pro-active, are mentioned. The complexity of ageing problems will be evaluated by looking in more detail to the evolution in concrete mix design and the consequences thereof for the long-term performance of concrete structures. In this evaluation different kinds of driving forces contributing to ageing will be identified. Emphasis will be on ageing of concrete infrastructure and the need of research on ageing phenomena will be addressed.Materials and Environmen