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This e-book has been made in the framework of the European Training Network on Durable, Reliable and Sustainable Structures with Alkali-Activated Materials (DuRSAAM), which organized a training course on AAM technology held at Karlsruhe Institute of Technology 27-29 January 2020. This open source book collects the lecture notes by the teachers of this training course and provides building professionals and stakeholders new insights on alkali-activated concrete as an emerging building technology.

Based on an extensive literature review, the aim of this report issued by the URBCON project is to understand the policy context in which the URBCON project eventually will be operating in. Which policies at EU, national and local level are in favour of the URBCON concept of alkali-activated concrete making use of local by-products. How can policies support and drive the further uptake of eco-concrete technologies, and which potential barriers the project will face in terms of legislation, economic, institutional, environmental and social aspects., Grant: Interreg North-West Europe project URBCON - By-products for sustainable concrete in the urban environment

Concrete is one of the most popular building materials, making it also of concern when considering the environmental impact of the construction sector and the associated built environment. For example, the construction sector is responsible for over 35% of the EU’s waste generation, buildings account for 40% of energy consumed, construction activities require a vast amount of resources and cement, being a major component of concrete, accounts for 5 to 8% of the carbon emissions. Although concrete performs quite well in terms of environmental impact compared to other construction materials, its wide use makes sustainability of concrete crucial in minimizing the environmental impact, as can be characterized from life cycle assessments. Eco-friendly or circular concrete solutions are investigated widely in view of lowering environmental impact, while keeping the high technical performance expected from contemporary building solutions. The durability, sustainability and life cycle assessment of such emerging solutions is of considerable importance in the framework of the Green Deal or similar visions, and highlights the need for engineers skilled in these subjects. This also formed the motivation in organizing an introductory training course on durability, sustainability and life cycle assessment of concrete structures, which is at the basis of this eBook.

The article belongs to the Special Issue Eco-performance of Alternative Binder Systems ispartof: Applied Sciences-Basel vol:11 issue:1 status: Published online

Concrete structures are widely used for buildings, transportation, infrastructure, and maritime applications. Their design, durability and performance directly influence social and economic growth. The downside of using concrete is linked to issues of durability and enormous environmental costs, as the cement industry is responsible for 8% of the world’s anthropogenic carbon dioxide emissions. In addition, around 60% of all non-renewable resources are used in construction, making it one of the least sustainable industries. There is a clear demand for a new, sustainable generation of building materials, as concrete based on Ordinary Portland Cement (OPC) cannot meet all the challenges of modern society in terms of durability and sustainability. The DuRSAAM action addresses this by establishing a training and research network that contributes to a sustainable built environment and uses alkali-activatable materials as a new generation of cement-free binders for concrete.

Repair mortars are costly materials with high level of Portland cement and various additives which questions their eco-efficiency. In this respect, cement free material solutions such as alkali-activated mortars based on ground granulated blast furnace slag (BFS) are gaining interest for structural repair. The aim of this research is to study blast furnace slag as a precursor for producing ambient cured alkali-activated repair mortars. To achieve this purpose, a total of four mixtures were prepared using four different molar ratios of the silicate solution. The fresh and hardened properties of the produced mortars including flow retention, dry density, compressive and flexural strength are studied comparing ambient-cured and sealed-cured specimens. Furthermore, the tensile bond strength between the repair mortars and a grit blasted concrete substrate was verified (after 7 days sealed + 21 days ambient curing). The results demonstrate, for the tested configurations, the feasibility of the alkali-activated repair mortar, including a good adherence. Given the limited scope of the tests, more work is needed to confirm the observations further.

This eBook has been made in the framework of the European Training Network on Durable, Reliable and Sustainable Structures with Alkali-Activated Materials (DuRSAAM), which organized a training course on AAM technology held at Karlsruhe Institute of Technology 27-29 January 2020. This open source book collects the lecture notes by the teachers of this training course and provides building professionals and stakeholders new insights on alkali-activated concrete as an emerging building technology.

In December 1996, CEB established a Task Group with the main objective to elaborate design guidelines for the use of FRP reinforcement in accordance with the design format of the CEB-FIP Model Code and Eurocode2. With the merger of CEB and FIP into fib in June 1998, this Task Group became fib TG 9.3 FRP Reinforcement for concrete structures in Commission 9 Reinforcing and Prestressing Materials and Systems. Finally, as a result of the restructuring of fib’s Commissions and Task Groups at the end of 2014, the Task Group became fib T5.1 FRP Reinforcement for concrete structures, chaired by Stijn Matthys at Ghent University, in Commission 5 Reinforcements. The work of former TG 9.3 and current T5.1 was performed by two working parties (WP), one of which is “Externally Applied Reinforcement” (EAR), which produced fib bulletin 14 “Externally bonded FRP reinforcement for RC structures” in July 2001. Following a number of years of relatively slow activity, the WP on externally applied reinforcement was reactivated and started working on an update of bulletin 14. The result of this work is summarised in the present technical report, which aims to give design guidelines on the use of externally applied FRP reinforcement (both externally bonded and near-surface mounted) for concrete structures. An attempt has been made to present some of the topics in a Eurocode-compatible format, so that the material covered may form the basis for the introduction of composites in the next version of Eurocode 2 and for the updating of the text on seismic retrofitting with composites in the next version of Eurocode 8. All persons who participated in the preparation of this Bulletin are mentioned in the copyright page. Further acknowledgements are due to Josée Bastien (Canada), Hans Rudolf Ganz (Switzerland) and Luc Taerwe (Belgium) for revision of the document. To all members of the working party on externally applied reinforcement our sincere thanks are expressed for the high quality and extensive work brought in on a voluntary basis.

The present paper discusses experimental work on the efficiency of externally bonded reinforcement (EBR) on reinforced concrete (RC) slabs under blast loads using an explosive driven shock tube (EDST). This study focuses on four tests which have been performed on simply supported RC slabs retrofitted with carbon fiber reinforced polymer (CFRP) strips and subjected to explosions for the same pressure and impulse. Pressure transducers are fixed at the end of the tube to measure the pressure of each experiment. Maximum deflection and strain distribution in the concrete and CFRP strips are recorded using digital image correlation (DIC) measurements. Due the explosion, the RC slabs are submitted to a dynamic vibration in both directions and during the first inbound displacement phase, the kinetic energy of the retrofitted specimen is stored as elastic strain energy in CFRP strips. All this elastic strain energy stored in FRP strips is violently released as kinetic energy during the rebound phase of the slab. The results indicate that EBR increases significantly the flexural capacity and the stiffness of RC slabs under blast loads.

The use of carbon fiber reinforced polymer (CFRP) as externally bonded reinforcement (EBR) for strengthening reinforced concrete (RC) structures that are loaded by a blast wave is confirmed as an efficient solution. This in addition to other advantages of CFRP such as high tensile strength, light weight and durability. This paper aims to investigate the blast response of reinforced concrete (RC) slabs retrofitted with carbon fiber reinforced polymer (CFRP) as externally bonded reinforcement (EBR) under two independent explosions. In order to achieve this objective, four simply supported slabs were tested using an explosive driven shock tube (EDST) to generate a reflected pressure equal to 3 MPa in the first explosion and a reflected pressure equal to 7.5 MPa in the second explosion. Digital image correlation (DIC) is used to measure the strain evolution in the concrete and the CFRP strips during the first explosion. The slabs retrofitted with increasing the quantity of fibers show a reduction in the residual deflection after two independent explosions. The results show that for the first explosion, EBR increases the flexural response and the stiffness of the RC slabs. In the second explosion, a total debonding of the CFRP strips occurs and initiates from the midspan of the slabs toward the supports. When the total debonding of the CFRP strips occurs, the strain distribution in the steel rebars are the same for all slabs regardless of the quantity of applied EBR.

Solid waste management in urban developed areas include collection, sorting, recycling of waste; the rest is incinerated. The incineration process, in addition to disinfection, reduces the volume of waste by 90% and 70% by weight.1 The remaining residues are further sorted to separate ferrous and non-ferrous metals. Most of the incinerators used for incinerating municipal solid and non-hazardous wastes are of grate furnace type, and the different fractions of ashes are named based on the location of collection and the size of the fraction. Bottom ashes are classified as non-hazardous, and those which conform to environmental and technical specifications are used mainly as road subbase material, and for other construction applications. The utilisation of residues helps to establish a circular economy, and saves landfill space and taxes and also reduces the need for mining of primary raw materials. These residues have the potential to be utilised in a higher value application such as a cement replacement, as a cement raw meal additive, and as aggregates. Certain properties of the material are obstacles that hinder the effective utilisation. Ongoing investigations explore different methods to beneficiate residues and make them fit to be used for potential high value applications.

This paper investigates the effectiveness of carbon fiber reinforced polymer (CFRP) as externally bonded reinforcement (EBR) to improve the flexural resistance of reinforced concrete (RC) slabs under blast loads. Three simply supported RC slabs are subjected to blast loading using an explosive driven shock tube (EDST). The obtained experimental results of the RC slabs without and with EBR are presented and discussed with the aim of evaluating the influence of EBR on the blast response of the RC slabs. A numerical analysis is carried out using the finite element software LS-DYNA to complement the experimental results. The bond interface between CFRP strips and concrete is simulated with a specific contact algorithm including the normal and shear stresses at the interface with failure criteria. The numerical analysis shows good agreement with the experimental results for the maximum deflection at the mid span of the slabs and good prediction of the distribution of cracks. CFRP strips as EBR increase the flexural capacity and the stiffness of the slabs. A reduction in the blast induced maximum deflection is recorded for the slabs retrofitted with CFRP strips.

In the last years Near Surface Mounted (NSM) reinforcement has mainly been applied at ambient temperature, to strengthen reinforced concrete (RC) beams with FRP (fibre reinforced polymer) materials. Thereby, FRP bars/strips are embedded inside the concrete section by means of grooves filled with adhesive. The behaviour of FRP-NSM strengthening systems at elevated temperature is signicantly influenced by the type of adhesive (e.g. cementitious grout is usually more stable than epoxy resin at high temperature). To characterize the FRP-NSM behaviour two steps are needed: 1) shear tests performed in order to determine the FRP-concrete interaction via bond stress-slip curves and 2) constitutive bond stress-slip relationships for use in structural design (analytical and numerical). Hereby, the bond behaviour is to be considered temperature dependent. During two experimental campaigns, double bond shear tests were performed in order to study the behaviour of FRP-NSM systems at elevated temperature using different types of adhesive, epoxy resin and cementitious grout respectively. The bond shear stress-slip curves are discussed including the effect of different types of adhesive. Simplified bond stress-slip relationships are proposed to model the FRP-concrete interaction at high temperature.

This paper discusses the structural fire design of reinforced concrete beams strengthened in flexure by means of externally applied reinforcement (EAR). It is focusing on the Eurocode approach for fire rating of individual members. Three different fire safety approaches are presented, depending on the strengthening ratio. Applicability of fire design methods, such as the use of the tabulated data and 500°C isotherm methods by EN1992-1-2, is indicated. Results show the importance of a well thought approach in the structural fire design of EAR, being a popular strengthening technique for concrete members. Through this strengthening solution, the load bearing capacity of existing members is strengthened or retrofitted, both in service conditions and at ultimate limit state. The EAR strengthening relies on a good bond interaction between the existing member and the externally applied reinforcement. However, given the weak properties of the bond interface at elevated temperatures, the fire performance is of special concern in the structural design of EAR strengthened reinforced concrete.

A theoretical investigation of membrane actions including compressive membrane action (CMA) and tensile membrane action (TMA) in one-way concrete members (i.e. beams and slabs) externally strengthened with Fiber Reinforced Polymer (FRP) is conducted in this paper. The favourable properties of membrane actions and its predictive modelling are first presented. An extended Park and Gamble’s method is proposed to account for the CMA effect and a spring based model is selected to consider the effect of TMA. By defining an enhancement factor, the study focuses on how CMA and TMA affect the load bearing capacities of the members considered with material parameters such as the FRP reinforcement area and steel reinforcement area. The results show that the effect of CMA on the load bearing capacity is more pronounced in beam members than in slab members, whereas the opposite applies to the enhancement factors of TMA between beams and slabs. A comparison of membrane action between conventional reinforced concrete (RC) members and FRP-strengthened RC members is given as well. Finally, remarks on how to make use of the favourable properties of membrane actions are presented.