Global warming, caused by a significant increase in the concentration of greenhouse gases (GHGs) such as CO2, has become a concern all over the world. The whole process carbon emissions of the civil engineering industry account for nearly 40% of global energy and process-related CO2 emissions, more than half of which come from the process of producing, using, constructing and dismantling in civil engineering materials and structures, resulting in the embodied carbon emissions. With the acceleration of global warming, warmer and uncertain climates will make engineering materials and structures subject to more severe environmental conditions. A series of durability issues will occur more frequently, such as the significant variations of humidity in air, the chloride-induced corrosion caused by the severe chloride ingress, concrete cracking caused by the expansion of rusts, and more severe carbonation of concrete structures due to the increase in CO2 concentration. The adoption of positive measures to address climate change has become a global consensus, as global warming has led to serious threats and challenges to the survival and development of humankind.

"In the research project presented in this PhD-thesis, an innovative type of fibre concrete is developed, with improved both the tensile strength and the ductility: the Hybrid-Fibre Concrete (HFC). The expression "Hybrid" refers to the "hybridisation" of fibres: short and long steel fibres were combined together in one concrete mixture. This is opposite to conventional steel fibre concretes, which contain only one type of fibre. The basic goal of combining short and long fibres is from one side to improve the tensile strength by the action of short fibres, and from the other side to improve the ductility by the action of long fibres." "In this research project, all important aspects needed for the development and application of Hybrid-Fibre Concrete have been considered. In total 15 mixtures, with different types and amounts of steel fibres were developed and tested in the fresh state (workability) as well as in the hardened state (uniaxial tensile tests, flexural tests, pullout tests of single fibres and compressive tests). A new analytical model for bridging of cracks by fibres was developed and successfully implemented for tensile softening response of HFC. At the end, the utilisation of HFC in the engineering practice was discussed, including a case-study on light prestressed long-span beams made of HFC."--BOOK JACKET.

Ultra-high performance concrete (UHPC) is an advanced construction material that affords new opportunities for the future of the highway infrastructure. The Federal Highway Administration has been engaged in research on the optimal uses of UHPC in the highway bridge infrastructure since 2001 through its Bridge of the Future initiative. This report presents the state of the art in UHPC with regard to uses in the highway transportation infrastructure. Compiled from hundreds of references representing research, development, and deployment efforts around the world, this report provides a framework for gaining a deeper understanding of UHPC as well as a platform from which to increase the use of this class of advanced cementitious composite materials. This report will assist stakeholders, including State transportation departments, researchers, and design consultants, to grasp the capabilities of UHPC and thus use the material to address pressing needs in the highway transportation infrastructure.

Selected chapters from the German concrete yearbook are now being published in the new English "Beton-Kalender Series" for the benefit of an international audience. Since it was founded in 1906, the Ernst & Sohn "Beton-Kalender" has been supporting developments in reinforced and prestressed concrete. The aim was to publish a yearbook to reflect progress in "ferro-concrete" structures until - as the book's first editor, Fritz von Emperger (1862-1942), expressed it - the "tempestuous development" in this form of construction came to an end. However, the "Beton-Kalender" quickly became the chosen work of reference for civil and structural engineers, and apart from the years 1945-1950 has been published annually ever since. Ultra high performance concrete (UHPC) is a milestone in concrete technology and application. It permits the construction of both more slender and more durable concrete structures with a prolonged service life and thus improved sustainability. This book is a comprehensive overview of UHPC - from the principles behind its production and its mechanical properties to design and detailing aspects. The focus is on the material behaviour of steel fibre-reinforced UHPC. Numerical modelling and detailing of the connections with reinforced concrete elements are featured as well. Numerous examples worldwide - bridges, columns, facades and roofs - are the basis for additional explanations about the benefits of UHPC and how it helps to realise several architectural requirements. The authors are extensively involved in the testing, design, construction and monitoring of UHPC structures. What they provide here is therefore a unique synopsis of the state of the art with a view to practical applications.

At head of title: National Cooperative Highway Research Program.