Huge amounts of waste are being generated, and even though the incineration process reduces the mass and volume of waste to a large extent, massive amounts of residues still remain. On average, out of 1.3 billion tons of municipal solid wastes generated per year, around 130 and 2.1 million tons are incinerated in the world and in Belgium, respectively. Around 400 kT of bottom ash residues are generated in Flanders, out of which only 102 kT are utilized here, and the rest is exported or landfilled due to non-conformity to environmental regulations. Landfilling makes the valuable resources in the residues unavailable and results in more primary raw materials being used, increasing mining and related hazards. Identifying and employing the right pre-treatment technique for the highest value application is the key to attaining a circular economy. We reviewed the present pre-treatment and utilization scenarios in Belgium, and the advancements in research around the world for realization of maximum utilization are reported in this paper. Uses of the material in the cement industry as a binder and cement raw meal replacement are identified as possible effective utilization options for large quantities of bottom ash. Pre-treatment techniques that could facilitate this use are also discussed. With all the research evidence available, there is now a need for combined efforts from incineration and the cement industry for technical and economic optimization of the process flow.

The use of fiber-reinforced polymer (FRP) grid reinforcement for concrete slabs has been investigated, considering the behavior of the slabs in one-way bending and under concentrated loading. The behavior under the latter loading type will be considered in this second part of a two-part paper. From the performed punching tests and the analysis, a fairly strong interaction between shear and flexural effects was noted for most of the tested slabs. For the FRP-reinforced slabs with an increased reinforcement ratio or an increased slab depth (needed to fulfill the serviceability criteria in bending), the punching strength was similar to or higher than the tested steel-reinforced reference slabs. For most slabs, slip of the bars occurred resulting in higher deflections at failure. The calculation of the punching failure load according to empirical-based models (from different codes), a modified mechanical model, and an analytical model is evaluated.

For a reliable and efficient design of fiber reinforced polymer (FRP) wrapping reinforcement, an accurate stress–strain prediction of reinforced concrete (RC) columns confined with FRP composites is essential. The stress–strain characteristics of FRP-confined concrete have been extensively studied, testing small-scale cylindrical specimens. In this paper, the stress–strain response of axially loaded large-scale columns confined with FRP wrapping reinforcement is investigated. The effective circumferential FRP failure strain and the effect of increasing confining action on the stress–strain behavior of RC columns confined with FRP are examined. Different models for the prediction of the stress–strain behavior of FRP-confined concrete have been reviewed. The existing stress–strain models are applied to predict the stress–strain response of the experimental results presented in this study. A comparison between the experimental results and those predicted by the existing models are presented. Few of the avail...