Concrete is the substance most consumed by humanity after water. Blended cements in which part of the energy intensive clinker is replaced by supplementary cementitious materials (SCMs) are the by far the most realistic means to obtain large scale CO2 reductions in the short-to-midterm, attending the urgency of the climate emergency. LC3, blended cement produced by the combination of limestone, calcined clays and Portland cement provides a solution that achieves equivalent mechanical performance to OPC, better durability against chloride penetration and ASR and a reduction of CO2 emissions by about 40%. Due to the similarities of LC3 with OPC, it is a material that can be adopted today using the same construction equipment and workforce worldwide.

Portland cement concrete has shown great potential for recycling different waste materials. Solid waste incorporated concrete (SWC) is considered to have positive environmental advantages. However, the utilization of solid wastes may negatively impact the mechanical performance and durability of concrete. Therefore, any change in the performance metrics of SWC should be accounted for in the comparative life cycle assessment (LCA). This article will review the functional equivalency with respect to the mechanical performance and durability metrics for SWC incorporating four main streams of solid wastes; recycled concrete aggregate, municipal solid waste incineration ashes, scrap tire rubber, and polyethylene terephthalate. It will be shown that while in most cases, SWC may have an inferior compressive strength and/or durability pre-treatment, sorting, and appropriate replacement rate of the solid wastes may solve the problem and make SWC functionally equal to the conventional concrete. Moreover, some types of SWC such as those incorporating scrap tire rubber and polyethylene terephthalate may be more advantageous if used in specific applications where dynamic loads are prevalent given their superior impact resistance. Finally, the article will discuss new insights into defining the functional unit based on the performance and application of SWC to conduct a reliable LCA.

The current market of utility poles is growing rapidly. The dominant materials that are used for this purpose are generally wood, steel, concrete, and fiber-reinforced polymers (FRP). FRP poles are gaining wide acceptance for what they provide in terms of strength and durability, lack of maintenance and a high strength to weight ratio. Hybrid structures can combine the best properties of the materials used, where each part enhances the structure to provide a balanced structure. This study evaluates a hybrid structure composed of three main layers, an outer FRP shell, a hollow concrete core and an inner hollow steel tube, this whole system is to be utilized as a tapered utility pole. The outer FRP shell provides protection and enhances the strength of the pole, the concrete core provides stiffness, and the inner steel tube enhances the flexural performance while reducing the volume in consequence the weight of the structure compared to a fully filled pole. A new design for a 12-feet long hybrid FRP pole using finite element is presented in this paper. The design was based on a parametric study evaluating the effect of key-design parameters (i.e., the thickness of FRP, the volume and strength of the concrete, the thickness and diameter of the steel tube). Concrete strength affected the general performance of the pole, the decrease in concrete strength due to utilizing lightweight concrete was compensated with increasing the FRP pole thickness. For the same pole configuration, with incremental variation of the FRP thickness values from 3 mm to 7 mm up to the initial concrete cracking load, no significant variation of the pole top deflection was observed. However, at failure load the increase of FRP thickness from 3 mm to 7 mm decreased the ultimate tip deflection by 50%. New hybrid utility poles have the potential to be an interesting alternative solution to the conventional poles as they can provide better durability and mechanical performances.

This study explores technological advancements enabling the utilization of GFRP bars in concrete structures, particularly in coastal areas. However, GFRP bars often encounter reduced bend strength at specific bend locations, which may pose a challenge in their practical application. Various properties such as the strength of bent GFRP bars are crucial for quality assurance, yet existing testing methods stated in ASTM D7914M-21 and ACI 440.3R-15 have limitations when applied to different GFRP bent shapes. Furthermore, those methods require special precautions to ensure symmetry and avoid eccentricities in specimens. To address these challenges, CSA S807:19 introduced a simpler standardized testing procedure that involves embedding a single L-shaped GFRP stirrup in a concrete block. However, the specified large block size in CSA S807:19 Annex E may pose difficulties for both laboratory and on-site quality control tests. Therefore, CSA S807:19 Annex E (Clause 7.1.2b) permits the use of a customized block size, as long as it meets the bend strength of the FRP bars without causing concrete splitting. To date, very few prior research has explored the use of custom block sizes. Therefore, this study aims to thoroughly investigate the strength of bent FRP bars with custom block sizes and without block confinement. Such an investigation serves to highlight the user-friendliness and efficiency of the CSA S807:19 Annex E method. The study recommends two block sizes: 200x400x300 mm (7.87x15.75x11.81 in) for bars <16 mm (0.63 in) diameter and 200x200x300 mm (7.87x7.87x11.81 in) for bars <12 mm (0.39 in). Additionally, the study cautions against using confinement reinforcement, especially with smaller blocks, as it could interfere with the embedded bent FRP bar. Furthermore, the study suggests incorporating additional tail length to mitigate the debonding effects resulting from fixing the strain gauges to the bent portion of the embedded FRP bar. By exploring these modifications, the study seeks to enhance the effectiveness of the testing procedure and expand its practical application for both laboratory and on-site quality assurance. The findings hold implications for the reliable testing of GFRP bars' strength, advancing their use as reinforcement in concrete structures.

Masonry structures are very sensitive to out-of-plane mechanisms under horizontal actions. A common traditional technique to avoid or mitigate the activation of these mechanisms is represented by injected anchors made of steel bars aimed to improve the connections between orthogonal masonry walls or between floors and masonry walls. The bars are usually embedded in the masonry by means of cement-based grout in holes realized inside the elements to be connected. Recently, an increased interest has developed in the scientific community about the use of Fibre Reinforced Plastic (FRP) bars as alternative to the steel ones for injected anchors, mainly because of their high tensile strength and inertia to corrosion, which can give them high durability, in addition to the use of high-performance grouts. The paper reports the results of experimental pull-out tests realized by the Authors on several types of FRP bars used as injected anchors in small masonry specimens made of yellow tuff blocks. A hydraulic lime and pozzolana-based grout is used to fix the bars in holes realized in the masonry specimens along an embedded length of 250 mm. The set-up is realized in order to apply pure tension to the bars and shear stresses along the bar-grout and the grout-masonry interfaces. The results are analysed in terms of maximum pull-out forces, failure modes and force-displacement relations in order to evidence the global performance of each tested system, especially in relation with the diameter and the surface treatment of the bars. Some comparisons with literature formulation for predicting the pull-out force are developed too.