Incorporating recycled plastic waste in concrete manufacturing is one of the most ecologically and economically sustainable solutions for the rapid trends of annual plastic disposal and natural resource depletion worldwide. This paper comprehensively reviews the literature on engineering performance of recycled high-density polyethylene (HDPE) incorporated in concrete in the forms of aggregates or fiber or cementitious material. Optimum 28-days’ compressive and flexural strength of HDPE fine aggregate concrete is observed at HDPE-10 and splitting tensile strength at HDPE-5 whereas for HDPE coarse aggregate concrete, within the range of 10% to 15% of HDPE incorporation and at HDPE-15, respectively. Similarly, 28-days’ flexural and splitting tensile strength of HDPE fiber reinforced concrete is increased to an optimum of 4.9 MPa at HDPE-3 and 4.4 MPa at HDPE-3.5, respectively, and higher than the standard/plain concrete matrix (HDPE-0) in all HDPE inclusion levels. Hydrophobicity, smooth surface texture and non-reactivity of HDPE has resulted in weaker bonds between concrete matrix and HDPE and thereby reducing both mechanical and durability performances of HDPE concrete with the increase of HDPE. Overall, this is the first ever review to present and analyze the current state of the mechanical and durability performance of recycled HDPE as a sustainable construction material, hence, advancing the research into better performance and successful applications of HDPE concrete.

Purpose: The purpose of the study is to mainstream the disaster risk reduction (DRR) and disaster resilience measures into the GreenSL® building rating system in Sri Lanka to demonstrate a more holistic approach in achieving sustainability with resilience.Design/methodology/approach: First, a comprehensive literature review was carried out on green building practices and rating tools, natural hazards and DRR and global and local frameworks. Next, criteria were developed incorporating the disaster resilience aspects through eight expert committee meetings and included the rating tool in three levels. Finally, 11 green-certified buildings from the Green Building Council of Sri Lanka were reevaluated using the new disaster resilient GREENSL® rating system for built environment as a validation for the new tool and to analyze the new certification levels.Findings: All the green-certified buildings in hazard-prone areas dropped their certification by one level while the buildings in nonhazard-prone areas remained in the certification after being evaluated by the new DRR-incorporated rating system, which recommends the use of new tool for the buildings in hazard-prone areas. But due to the rapid changes in climate and the unpredictable trends of natural hazards, the use of new DRR incorporated GREENSL® rating system for built environment for the certification of buildings is highly endorsed.Originality/value: This is the first research study based on the GREENSL rating system. And it is the first effort to incorporate DRR aspects to any rating tool in Sri Lanka. The projects that were evaluated for the validation of the new tool are the actual projects which obtained green building certification. Also, it is apparent that this study has gone some way towards enhancing the understanding of blending the sustainability and resilience in rating systems for built environment.

Ballasted tracks are being overstressed as the demand for faster and heavier trains grows, resulting in excessive deterioration, frequent maintenance, and increased life-cycle cost of the track. Therefore, advancements in track constructions, such as elastic inclusions, to improve track performance and minimize maintenance frequency while enhancing safety are imperative. This paper explores a critical review of various types of elastic inclusions used in ballasted tracks. Individual performances of popular types of elastic inclusions such as energy-absorbing rubber mats, tyre derived aggregates, waste rubber tyres, and polyurethane-based inclusions were identified from the literature, and recommendations for their use depending on field requirements were proposed. Many studies have confirmed the contribution of energy-absorbing rubber mats in improving the performance of both substructure and superstructure of the track, but further investigations are required for other types of elastic inclusions, mainly in terms of their impact on track superstructure behaviour.

The increased demand for cladding in high-rise buildings has prompted engineers to explore alternative products utilizing recycled materials. However, ensuring fire compliance in these alternative claddings, which are predominantly composed of low-volume polymer-based composites, poses a critical challenge. Traditional experimental methods for fire evaluation are costly, time consuming, and environmentally impactful. Considering this, a numerical approach was proposed for evaluating the fire performance of glass-polymer composite materials, which contain a high proportion of recycled glass and a lower percentage of rigid polyurethane. A cone calorimeter test was simulated using Computational Fluid Dynamics (CFD) software to investigate the flammability of the novel glass–polymer composite material. This validated numerical model was employed to assess the combustibility of the glass–polyurethane composite materials and identify influential parameters using the Design of Experiments (DoE) method. Statistical analysis revealed that three material properties, namely, the heat of combustion, the absorption coefficient, and the heat of reaction, significantly influenced the peak heat release rate (pHRR) of the glass–polyurethane composite materials compared to other properties. Based on these findings, an empirical equation was proposed that demonstrates a reasonable correlation with the pHRR of low-polymer recycled glass composite materials. The outcomes of this study hold considerable importance for understanding and predicting the combustibility behaviour of low-polymer–glass composites. By providing a validated numerical model and identifying critical material properties, this research contributes to the development of sustainable fire safety solutions for buildings, enabling the use of recycled materials and reducing reliance on conventional claddings.