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Waste glass is an endless issue for the majority of the countries in the world with a linear economy of usage of materials. Demolition waste is counted as part of total construction and demolition waste (CDW). Even today, there are some statistical problems with the quantification of demolition waste and dividing it from total CDW, since most countries do not provide such a division of waste types. The current review shows possible ways of utilizing waste glass in some useful products in the construction industry. It is elaborated using PRISMA@ methodology with bibliometric and qualitative methods to provide a systematical overview of the publications in the period from 2000 to 2023. The bibliometric search was handled with the application RStudio© using sources in the biggest database, Scopus. Most of the published research items are mainly focused on using waste glass in concrete applications. However, there are seven possible areas of waste glass application in the construction industry: concrete products, gypsum–cement composites, asphalt or concrete pavement, geopolymer mortars, foamed glass ceramics, glass ceramics, and soil foundation strengthening/stabilization. In its turn, the circular economy should be applied since it provides a prolonged turnaround of materials throughout their life cycle.

The scientific community is shifting its focus towards construction materials with a low carbon footprint, such as alkali-activated concrete (AAC). The present study conducts an environmental impact assessment using the cradle-to-grave approach to examine the environmental implications of three different types of ambient-cured AACs with varied combinations of precursors. The 28-day compressive strength values of the concrete mixes used for comparing environmental impacts vary from 35 to 55 MPa. Among these mixtures, the one with the least environmental impact is chosen for further impact assessment with the inclusion of fibers. Three different fiber reinforced AAC mixes containing 0.3% steel, glass, and polypropylene fibers, respectively by volume of AAC, are used in this study. The findings show that Portland Cement concrete has 86% and 34% higher impacts than AAC on the ecosystem and human health, respectively. In the production of AAC, sodium silicate is found to have the highest impact on the environment, in the range of 30–50% of the total impact. Among the various fibers used, glass fibers have the highest impact, which is 12% and 13% higher than that of the plain AAC mix, on the ecosystem and human health, respectively.

Alkali-activated binders (AABs) offer the opportunity to upcycle a variety of residues into products that can have added value. Although AABs are reported to have a superior high-temperature performance, their thermal behavior is heavily governed by their microstructure. The present study, therefore, evaluates the effect of varying fly ash:slag ratios, activator modulus (Ms), and high temperatures on the microstructure of AAB using X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy coupled with energy-dispersive spectroscopy. Furthermore, the mechanical properties of alkali-activated concrete (AAC) are investigated through compressive, bond, flexural, and split tensile strengths. A life cycle assessment of AAC is performed using the ReCiPe 2016 methodology. The results from microstructural experiments show the formation of new crystalline phases and decomposition of reaction products on high temperature exposure, and they correlate well with the observed mechanical performance. The 28-days compressive strength with slag content is enhanced by 151.8–339.7%. AAC with a fly ash:slag ratio of 70:30 and Ms of 1.4 is proposed as optimal from the obtained results. The results reveal that the biggest impact on climate change comes from transport (45.5–48.2%) and sodium silicate (26.7–35.6%).

Nowadays, a vast number of concrete structures are approaching the end of their expected service life. The need for maintenance and repair is high due to the continued deterioration of the existing building inventory and infrastructure, resulting in a large need for concrete repair in the near future. Reinforcement corrosion is the most important deterioration mechanism, causing (i) severe concrete damage (cracking along reinforcement and the spalling of the cover concrete) and (ii) loss in steel section. Therefore, appropriate repair techniques for corrosion damage are the main focus of this review paper. With the European transition towards a circular economy and with sustainable development goals in mind, it is also important to consider the environmental impact along with the technical requirements and life cycle cost. In order to improve the sustainability of concrete structures and repairs over their life cycle, life cycle assessment (LCA) and life cycle cost analysis (LCCA) should be applied. However, more research efforts are needed in this field for further development and refinement. This literature review tries to adress this need by compiling existing knowledge and gaps in the state-of-the-art. A comprehensive literature survey about concrete repair assessment through LCA and LCCA is performed and showed a high potential for further investigation. Additionally, it was noticed that many differences are present between the studies considering LCA and/or LCCA, namely, the considered (i) structures, (ii) damage causes, (iii) repair techniques, (iv) estimated and expected life spans, (v) LCCA methods, (vi) life cycle impact assessment (LCIA) methods, etc. Therefore, due to the case specificity, mutual comparison is challenging.

This state-of-the-art review was aimed to conduct a comprehensive literature survey to summarize experiences of crumb rubber (CR) application in concrete within the last 30 years. It shows that certain gaps prevent obtaining a coherent overview of both mechanical behaviour and environmental impact of crumb rubber concrete (CRC) to object to the stereotypes which prevent to use of CR in concrete in the construction industry. Currently, four major barriers can be distinguished for a successful CR application in the concrete industry: (1) the cost of CR recycling, (2) mechanical properties reduction, (3) insufficient research about leaching criteria and ecotoxicological risks and (4) recyclability of CRC. The application of CR in concrete has certainly its advantages and in general cannot be ignored by the construction industry. CR can be applied, for example, as an alternative material to replace natural aggregates and CRC can be used as recycled concrete aggregates (RCA) in the future. A certain diversity for the CR application can be introduced in a more efficient way when surface treatment and concrete mix design optimization are properly developed for each type of CR application in concrete for possible field applications. The role of CRC should not be limited to structures that are less dependent on strength.

The negative environmental impacts associated with the usage of Portland cement (PC) in concrete induced intensive research into finding sustainable alternative concrete mixes to obtain “green concrete”. Since the principal aim of developing such mixes is to reduce the environmental impact, it is imperative to conduct a comprehensive life cycle assessment (LCA). This paper examines three different types of sustainable concrete mixes, viz., alkali-activated concrete (AAC) with natural coarse aggregates, AAC with recycled coarse aggregates (RCA), and bacterial concrete (BC). A detailed environmental impact assessment of AAC with natural coarse aggregates, AAC with RCA, and BC is performed through a cradle-to-gate LCA using openLCA v.1.10.3 and compared versus PC concrete (PCC) of equivalent strength. The results show that transportation and sodium silicate in AAC mixes and PC in BC mixes contribute the most to the environmental impact. The global warming potential (GWP) of PCC is 1.4–2 times higher than other mixes. Bacterial concrete without nutrients had the lowest environmental impact of all the evaluated mixes on all damage categories, both at the midpoint (except GWP) and endpoint assessment levels. AAC and BC mixes are more expensive than PCC by 98.8–159.1% and 21.8–54.3%, respectively.

This Special Issue “Recent Advances and Future Trends in Pavement Engineering” has been proposed and organized to present recent developments in the field of innovative pavement materials and engineering. For this reason, the articles and state-of-the-art reviews highlighted in this editorial relate to different aspects of pavement engineering, from recycled asphalt pavements to alkali-activated materials, from hot mix asphalt concrete to porous asphalt concrete, from interface bonding to modal analysis, from destructive testing to non-destructive pavement monitoring by using fiber optics sensors.

Moisture susceptibility is still one of the primary causes of distress in flexible pavements, reducing the pavements’ durability. A very large number of tests are available to evaluate the susceptibility of a binder aggregate combination. Tests can be conducted on the asphalt mixture, either in a loose or compacted form, or on the individual components of an asphalt pavement. Apart from various mechanisms and models, fundamental concepts have been proposed to calculate the thermodynamic tendency of a binder aggregate combination to adhere and/or debond under wet conditions. The aim of this review is to summarize literature findings and conclusions, regarding these concepts as carried out in the CEDR project FunDBits. The applied test methods, the obtained results, and the validation or predictability of these fundamental approaches are discussed.

Pavement design is essentially and usually a structural long-term evaluation process which is needed to ensure that traffic loads are efficiently distributed at all levels of the total road structure. Furthermore, to get a complete analysis of its durability behavior, long-term monitoring should be facilitated, not only from the top by falling weight deflectometer (FWD) or core drilling but preferably from inside the structure and at exactly the same positions during a long-time interval. Considering that it is very hard to devise an efficient method to determine realistic in-situ mechanical properties of pavements, the determination of strain at the bottom of asphalt pavement layers through non-destructive tests is of a great interest. As it is known, fiber Bragg grating (FBG) sensors are the most promising candidates to effectively replace conventional strain gauges for a long-term monitoring application in a harsh environment. The main goals of this paper are to compile an overview of the recent developments worldwide in the application of fiber optics sensors (FOS) in asphalt pavement monitoring systems; to find out if those systems provide repeatable and suitable results for a long-term monitoring; if there are certain solutions to validate an inverse modelling approach based on the results of FWD and FOS.

In this study, the feasibility of a natural peat fiber and finely ground peat powder as a modifier for bitumen was investigated. Initially, the as-received peat material was characterized in detail: the material was ground to various degrees, separated into fiber and powder fractions, and the gradation of the powder fraction as well as the size of the fibers were determined. A possible solubility in bitumen, the moisture content, and the density of both fractions were evaluated, and a limited chemical characterization of the fibers was conducted. Secondly, the rheological behavior of the powder and the fibers when blended with bitumen was evaluated. Additionally, a limited asphalt study was conducted. The rheological data showed the stiffening effects of the powder fraction and the presence of a fiber network, which were obvious as a plateau modulus towards lower frequencies. The fiber network was strain-dependent and showed elastic effects. This was further confirmed by the multiple stress creep recovery (MSCRT) tests. These tests also indicated that the fibers should improve the rutting resistance, although it was not possible to confirm this in asphalt rutting tests. Asphalt drainage tests demonstrated that adding dry peat, whether this is ground or not, is effective in reducing the binder drainage. However, the data also revealed that the amount of added peat fibers and powder should be limited to avoid difficulties in the compaction of these asphalt mixes.

In the present study, a new approach to the installation of fiber Bragg grating (FBG) sensors in three asphalt pavement layers (the surface layer and both base layers) was implemented for the first time in Belgium. Fiber Bragg grating sensors (FBGs) are diagnostic tools that accurately and efficiently monitor in situ structural behavior. However, nowadays, this technology is not commonly used in asphalt due to its application restrictions under installation and service conditions. FBGs are fragile and break easily under loading. Therefore, there is a need for suitable protection of FBG sensors if they are to be installed during the rough construction process and exposed to heavy-duty loading afterwards. The main objective of the present study is to show the FBG results only for the initial construction process, and, if successful, to continue studying this FBG monitoring system and to plan the next research step by adjusting the system for its application in heavy-duty pavements. Two approaches to FBG installation in three asphalt layers (placed at the bottom of each layer) were tested in the present study: (1) installation of FBGs in prefabricated asphalt specimens in the base layer, directly on the base, and (2) installation of FBGs on the surface of the previously constructed asphalt layer. Both innovative approaches allow the implementation of FBGs without sawing the whole layer into two parts. The obtained results proved a survival rate of 100% for the FBGs. It can be concluded that these new described methods of FBG installation—using a cross-section configuration to carry out strain measurements in two directions (transverse and longitudinal)—can be applied for the monitoring of heavy-duty pavements, while providing the possibility to further re-evaluate current pavement design methods used in Flanders (Belgium).

The scope of the paper is to report an investigation on durability of infrastructure concrete for roads and bridges by creating a size and shape-designed pore systems in concrete in order to improve it, especially in terms of freeze–thaw resistance. By means of this experimental laboratory study, an alternative for usage of air entrainment agents (AEA) in concrete infrastructures was found in the way of using superabsorbent polymer materials (SAPs). The effect of the addition of SAPs of different amounts and different types into fresh concrete mix was investigated, including: compressive strength tests, weight loss measurements, visual and microscopic inspections and scanning electron microscopy (SEM) analysis. The detrimental strength reduction effect was not observed. The freeze–thaw procedure was varied, using different types of de-icing salts and heating/cooling regimes. It can be concluded that an improvement of the freeze–thaw resistance of concrete infrastructure depends on the particle size and optimal amount of SAPs added into concrete mix. The addition of 0.26 wt % of dry SAPs into the fresh concrete reference mix led to the significant decrease of scaling up to 43% after 28 freeze–thaw cycles. Both dosage and particle size of the SAPs had a significant impact on the obtained results and the freeze–thaw resistance in this experimental laboratory study.