This research provides useful insights into sustainable and cost-effective pavement rehabilitation by evaluating the combined effects of both Reclaimed Asphalt Pavement (RAP) and Crumb Rubber (CR) modification on flexible pavement performance using actual motorway sections. Pavement rehabilitation and maintenance can enhance the design and serviceable life of the pavement. Additionally, modification of asphalt with Crumb Rubber (CR) and Reclaimed Asphalt Pavement (RAP) not only proves to be economical but can also increase the resistance of flexible pavement concerning rutting, fatigue, and moisture damage. Four different pavement sections were selected, which were rehabilitated and modified with Reclaimed Asphalt Pavement (RAP), Crumb Rubber (CR), and a combination of both, along the Islamabad-Lahore motorway (M-2), Pakistan. The first pavement section consists of Asphalt Concrete Wearing Course (ACWC) with 60/70 grade bitumen as a binder (RAP 0%, CR 0%), the second pavement section was a mixture of asphalt concrete with crumb rubber modified bitumen as a binder (RAP0%, CR7%), the third pavement section was a blend of 15% RAP with 60/70 grade bitumen as a binder (RAP15%, CR 0%), the fourth section was a mixture of 15% RAP and 7% crumb rubber modified bitumen (RAP 15%, CR 7%). Pavement cores were extracted from the selected four pavement sections, which were experimentally explored in the laboratory to find the impact on the performance of highway pavement employing Reclaimed Asphalt Pavement (RAP) and Crumb Rubber (CR), partially replacing bituminous binder in the asphalt. The results show notable improvements in rutting resistance, tensile strength, and resilience. It was concluded that the performance of the section employing either RAP, CR or combined RAP and CR modified bitumen better enhanced the performance of pavement in terms of rut depth, indirect tensile strength and modulus of resilience. For instance, rutting depth was reduced by 41.35% and indirect tensile strength of pavement was increased by 17.93% by employing 15% RAP and 7% CR in modified bitumen binder for asphaltic mix. Likewise, the modulus of resilience was increased by 38.23% for the section employing 15% RAP and 7% CR in pavement.

This study aims to investigate the use of waste material combinations to produce sustainable concrete. Wood ash (WA), silica fume (SF), and fly ash (FA) were used as partial replacements for cement in normal cement concrete (NCC), self-compacting concrete (SCC), and lightweight self-compacting concrete (LWSCC). Waste plastic aggregates partially replaced fine and coarse aggregates in LWSCC. Twenty mix designs were tested for flowability and mechanical properties. In NCC, 10% SF replacement maximized the compressive, splitting tensile, and flexural strengths. Increasing the FA (0–30%) and WA (0–15%) contents reduced the strength, although the reductions were relatively small and acceptable. In SCC, increasing the WA (0–15%) with 10% SF and 20% FA slightly reduced the strength. Meanwhile, the addition of WA to SCC reduced the flow properties. However, all flow properties met the guidelines developed by the European Federation of National Associations Representing Concrete (EFNARC), and no visible blocking was observed during the flow characteristics test. LWSCC incorporated 25–100% plastic powder, 5% WA, 10% SF, 20% FA, and 30% plastic aggregates. Increasing plastic powder reduced strength, flowability, and density (below 1950 kg/m³); however, all mixes remained within EFNARC limits. This study demonstrates the potential utilization of waste materials in concrete, reducing cement and natural resource consumption and offering significant environmental benefits.

This study presents a flood risk assessment of five rural bridges along the monsoon-prone Khar–Mohmand Gat corridor in Northwestern Pakistan using an integrated hydrologic and hydraulic modeling framework. Hydrologic simulations for 50- and 100-year design storms were performed using the Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS), with watershed delineation conducted via Geographic Information Systems (GIS). Calibration was based on regional rainfall data from the Peshawar station using a Soil Conservation Service Curve Number (SCS-CN) of 86 and time of concentration calculated using Kirpich’s method. The resulting hydrographs were used in two-dimensional hydraulic simulations using the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) to evaluate water surface elevations, flow velocities, and Froude numbers at each bridge site. The findings reveal that all bridges can convey peak flows without overtopping under current climatic conditions. However, Bridges 3 to 5 experience near-critical to supercritical flow conditions, with velocities ranging from 3.43 to 4.75 m/s and Froude numbers between 0.92 and 1.04, indicating high vulnerability to local scour. Bridge 2 shows moderate risk, while Bridge 1 faces the least hydraulic stress. The applied modeling framework effectively identifies structures requiring priority intervention and demonstrates a practical methodology for assessing flood risk in ungauged, data-scarce, and semi-arid regions.

This paper presents a comprehensive reliability assessment of prestressed concrete bridges in Pakistan subjected to prevailing truck traffic conditions. The study compares actual load effects from weigh-in-motion (WIM) data with design specifications from the Pakistan Highway Bridge (PHB) Code (1967) and AASHTO LRFD. Statistical analysis of axle weights, configurations, and gross vehicle weights (GVW) reveals that 72.7% of trucks exceed legal load limits, with 5-axle trucks showing 97% non-compliance. Reliability analysis using First-Order Second Moment (FOSM) methods indicates that existing bridge designs exhibit significant variations in safety margins, with reliability indices (b) ranging from 2.51 (Chitral Bridge) to 5.6 (Bannu Road Bridge). The results demonstrate that current design codes do not accurately represent Pakistan's truck traffic, leading to potential overstressing or underutilization of bridges. The study recommends revising live load models based on empirical traffic data and implementing stricter enforcement of weight regulations to enhance bridge safety and longevity.

Material quality, environmental conditions, and traffic loads that lead to pavement deterioration pose significant challenges for the design of flexible pavements. This study concerns common distress affecting the surface course, which undermines its longevity and effectiveness. This key layer is composed of bituminous mixtures, and its behaviour directly influences the pavement’s durability. In the present study, it is proposed to improve the mechanical properties of these mixtures by adding Fuller’s earth, a natural clay with adsorptive properties and low cost. The modified mixtures were compared with conventional mixtures for strength and flow characteristics using the Marshall stability test. This modification was carried out by replacing the conventional filler with Fuller’s earth at replacement levels of 5% and 10% by weight. The prepared samples were tested rigorously to find the optimum replacement level. The modified mixes showed improved deformation and crack resistance, which indicates a significant improvement in overall pavement performance. The Marshall stability was increased by 28.42% for the mixture modified by 5 and 30.81% for the mixture modified by 10%. However, the difference between the two modification levels was 1.78% for stability and 2.22% for flow, indicating that the 5% Fuller’s Earth mixture provides a better balance between strength and material economy.

Rapid urbanization, uncoordinated land-use growth, and insufficient integration of public transport have led to severe traffic congestion and declining mobility in Peshawar, Pakistan, even after the implementation of a Bus Rapid Transit (BRT) system. The core research problem addressed in this study is the mismatch between growing travel demand and the limited capacity, coverage, and operational efficiency of the existing urban transport network. This research aims to evaluate the current performance of Peshawar’s transport system and to identify integrated, evidence-based strategies to alleviate congestion and enhance urban mobility. Specifically, the objectives are to assess roadway level of service on major corridors, examine public transport user satisfaction with the BRT system, and propose targeted infrastructure and operational improvements. A mixed-methods approach was employed, combining traffic volume and level-of-service (LOS) analysis, public transport user surveys, and field observations at critical intersections. The findings indicate that several key arterial roads operate at LOS E–F during peak hours, and future traffic projections indicate widespread capacity failures under existing road geometries. Survey results reveal significant dissatisfaction with the BRT system, particularly due to limited spatial coverage, inadequate feeder routes, overcrowding, and excessive travel times. Based on these results, the study proposes integrated interventions, including road widening and auxiliary lanes, geometric and signalized junction improvements, expansion of BRT feeder services, development of new arterial and ring roads, and enhanced pedestrian and parking infrastructure. This study links quantitative traffic performance measures with user-perceived service deficiencies. It provides practical, data-driven guidance for policymakers and planners to support a more efficient, accessible, and sustainable urban transport system in Peshawar.