Articles in This Issue
Abstract
The negative impacts of road traffic congestion in the Smart City environment are the subject of this study. Although the postponements are not entirely new, they are a well-known issue that affects a large portion of the worldwide population through pollution and postponements. In order to maintain flow and prevent traffic bottlenecks, there is a higher need for traffic management due to the growing urbanization and number of motorized motor vehicles. We use Peshawar Chowk, being one of Pakistan's most important urban and economic centers, it was chosen as a pilot research location. It is experiencing an uncontrolled phase of fast urbanization and motorization. The study first examines sustainable transportation systems to comprehend the idea of environmentally friendly transportation. The research then assesses to determine the most sustainable kind of transportation, considering Pakistan's current urban transportation and transportation infrastructure. Using AIMSUN software, the best option for a more environmentally friendly transportation system may be found. We do this by comparing the criteria and alternatives in pairs. A survey questionnaire is used to conduct this pair-wise comparison.
Abstract
This study examined the efficacy of Fly Ash Type F-based geopolymer binders in enhancing the impermeability of clayey soils. A clayey soil of the CL type was stabilized using geopolymer mixtures composed of fly ash activated by two different alkaline systems: (1) sodium silicate combined with lime and (2) sodium bicarbonate combined with lime. The FA binders were added at dosages of 10%, 20%, and 30% by weight of dry soil, and FA/AA was 0.2, 0.4, and 0.6. Standard falling head permeability tests were performed to evaluate the efficacy of the therapies. The experimen results indicated a marked improvement in reducing soil permeability with both alkaline activator systems. The greatest reduction was observed at a 30% replacement ratio when the sodium silicate–lime mixture was used. Beyond this level, a slight increase in permeability was recorded, which can be attributed to the excessive alkalinity of the mixture and the potential formation of microcracks. On the other hand, the sodium bicarbonate–lime system showed a consistent trend, where higher replacement levels continued to lower permeability. Overall, the study highlights that fly ash–based geopolymers, when properly optimized in terms of activator type and dosage, provide an effective and sustainable approach for improving the impermeability of clayey soils, particularly in hydraulic and geotechnical engineering applications
Abstract
A study was undertaken to produce lightweight aggregate concrete using artificial lightweight aggregate (Lytag) made from sintered fly ash. Cement or fly ash-based geopolymer was utilized as binder material, and its effect on the properties (compressive strength, water absorption, and thermal conductivity) of lightweight aggregate concrete was investigated. Two mixes were designed (using the absolute volumes method) and produced at a density of around 1350 kg/m3 as cement lightweight aggregate concrete and geopolymer lightweight aggregate concrete. Fly ash and an alkaline solution (sodium hydroxide and sodium silicate) were used to produce the geopolymer paste. The results indicated that the compressive strength, water absorption, and thermal conductivity of lightweight aggregate concrete made with geopolymer paste were better than those made with cement paste. An increase in compressive strength by about 49% and a decrease in water absorption and thermal conductivity by about 36% and 25%, respectively, were noticed in fly ash-based geopolymer lightweight mix compared to cement lightweight concrete mix.
Abstract
Self-Compacting Concrete (SCC) is a pioneering concrete that can gush beneath its own load, filling the formwork, and achieving full consolidation while maintaining sufficient cohesion to handle the concrete without segregation or bleeding issues. To develop EPS- fiber reinforced SCC, waste materials such as Expanded Polystyrene Beads (EPS) and waste plastic fibers (Polyethylene terephthalate (PET)) were incorporated. This study investigated the response of SCC to the incorporation of different ratios of PET fibers (0.35%, 0.5%, and 0.75%) and 10% of EPS particles and its impact on fresh and mechanical properties of SCC mixtures. Five SCC mixtures were designed, including the reference mixture, 10% EPS mixture, and three volume fractions (Vf) of PET mixtures. Test results indicated that EPS particles had an optimistic effect on fresh properties and a slight negative effect on mechanical properties. While PET fibers revealed a slight negative impact on fresh properties, they also improved mechanical properties. The highest and lowest values in fresh properties tests, including slump flow, T50, V-funnel, L-box, and sieve segregation were (780mm for (E %10) mix, 5.4 seconds for (0.75% f) mix, 19 second for (0.75% f) mix, 0.85 for (E %10) mix, and 10.77% for (R) mix), respectively and (670mm for (0.75% f) mix, 1.8 second for (E %10) mix, 6 seconds for (E %10) mix, 0 for (0.75% f) mix, and 3.28% for (0.5% f) mix), respectively. While, the highest and lowest values in mechanical properties tests, including density, ultrasonic pulse velocity (UPV), compressive strength, and splitting tensile strength were (2305 kg/m3 for (R) mix, 4.2 km/s for (R) mix, 48 MPa for (0.5% f) mix, and 3.66 MPa for (0.5% f) mix), respectively and (2170 kg/m3 for (0.5% f) mix, 4.03 km/s for (0.75% f) mix, 31 MPa for (E %10) mix, and 2.33 MPa for (E %10) mix), respectively
Abstract
A study of Al-Rayhanna Bridge (Iraq, Anbar Province) concerned with examining elastomeric bearing pad dynamic behaviour against changes in traffic speed and girder deflection. The areas of maximum deflection were being located at midspans of the girders, especially under truck or underneath truck lanes. One of the key contributions of the work was the application of the deflection measurements of the Linear Variable Differential Transformer (LVDT) for the estimation of car speeds, and a very welcoming mean value of 40.95 km/h (the visual timing correlations being >95 per cent), showed that structural measurement can be employed in reliable traffic analysis. The new bridge was defined by reduced damping ratio (3-4 % compared to 5-6 % of the old bridge) accounting for varying abilities to absorb and release energy. Thus, the new bridge appeared to require less balance restoration energy (1.5-2 seconds / 0.5-0.67 Hz) than the old bridge exhibiting faster stabilization (1-1.5 seconds / 0.67-1 Hz). The rate of amplitude decay also varied quite radically: 20-25 per cent per cycle for the new bridge compared to 30-35 per cent for the old bridge. Structural design and climatic dependent factors , indicates the significant role played by adopting dynamic factors - such as damping, energy dissipation and deflection patterns in bridge structure design and maintenance to guarantee long-lasting structural integrity and safety. These observations give conclusive feedback on upcoming resilient bridge construction, also the field of material science and traffic engineering
Abstract
One main natural hazard resulting from interactions between rainfall-runoff is flooding. Extreme precipitation causes surface water flow to rise, hence breaking river systems and causing flooding. This work models and forecasts flood dynamics in the Kunhar River basin with the Hydrologic Engineering Centre's Hydrologic Modelling System (HEC-HMS). It shows how well the technology can combine several hydrological data points to precisely project flood paths. These studies have repeatedly shown the dependability of HEC-HMS over many geographical and climatic environments, therefore confirming its fit for thorough hydrological research. HEC-HMS included obtaining thorough datasets comprising historical hydrological data from NASA, spatial information from ARCGIS, and meteorological data from WAPDA in addition to flow rates and water levels. We started the basin model in HEC-HMS by including Digital Elevation Models (DEMs) to define watershed boundaries and record topography. Terrain preprocessing came next to solve discontinuities and guarantee correct water flow modelling. Combining several datasets, the model was designed to reflect the coordinate system and underwent hydrological study to replicate surface water flow, accumulation, and stream networks inside the basin. With subbasin-10 showing the largest peak flow of 132 cubic meters per second during severe rainfall events, especially on August 7, 2013, results revealed that HEC-HMS effectively forecasted peak discharges in the subbasins of the Kunhar River. With an estimate 90% accuracy rate, this proved the great dependability of HEC-HMS in flood prediction. The results show that the model can help with flood management planning and foresee flood circumstances. HEC-HMS's value in designing flood barriers and enhancing watershed management particular to each subbasin. It emphasizes the need of revised hydrological models to consider land use and increasing temperature.
Abstract
The aim of this research is to experimentally evaluate the mechanical characteristics of mortar mixtures containing expanded polystyrene (EPS) beads and reinforced with polyethylene terephthalate (PET) fibers. Fine aggregates were partially replaced with 10% and 20% replacement ratios of expanded polystyrene beads, as well as four PET fiber volume fractions set at 0%, 0.5%, 0.75%, and 1%. Standard specimens for compressive strength, density, split strength, and flexural strength were used to assess the mechanical properties of hardened samples, while the slump test was used to gauge the fresh-state workability. The findings showed that the weight of the mortar reduced when EPS beads were used in place of fine aggregates. However, incorporating EPS beads into the mortar led to notable decrease in its mechanical properties. The workability was negatively impacted by the addition of PET fibers. However, when 0.75% PET fibers were added, PET reinforcement significantly increased compressive strength by 32% and 27% in mixes with 10% and 20% EPS, respectively. Splitting tensile and flexural strength exhibited minor fluctuations, with overall improvements remaining within approximately ±10%. The density and ultrasonic pulse velocity reduce when adding PET fibers. At 20% EPS and 1% PET, the concrete's density dropped to approximately 2030 kg/m³.
Abstract
Most concrete structures are reinforced with steel bars to enhance their performance. However, engineers face two major challenges: the high cost of steel compared to concrete and congestion of reinforcement, especially in beams and beam-column joints. These issues can largely be mitigated by using high-strength (HS) steel instead of normal-strength (NS) steel. This study investigates twelve concrete beams (150 × 250 mm), divided into three groups of four specimens. The first group was reinforced with NS steel bars, the second with HS steel, and the third with a combination of both. All beams were tested under four-point bending over a clear span of 2000 mm. Grade 1860 steel (G-270) was used for the HS steel reinforcement. Results showed that achieving the same flexural strength required nearly three times more NS steel than HS steel, leading to reduced reinforcement congestion, lower material usage, and decreased labor costs. Beam specimens were reinforced with steel contents of 1.80 kg/m (NS steel), 1.76 kg/m (HS steel), and 1.66 kg/m (combined reinforcement). Beams with HS steel showed significantly higher ultimate load capacity and improved stiffness (load-deflection behavior) compared to beams with NS steel or combined reinforcement. The analysis confirmed that the applied design method offers conservative and reliable predictions.
Abstract
This study investigates the influence of nano silica on the mechanical performance and interfacial behavior of fiber-reinforced cementitious composites (FRCCs) incorporating steel, glass, polypropylene, and raffia fibers. The objective is to evaluate the impact of nano-silica content (0%, 1.5%, 2.5%, and 3.5%) on workability, compressive strength, fiber–matrix bond strength, and tensile response under uniaxial loading. The addition of nano-silica reduced flowability due to its high surface area and water demand but enhanced compressive strength, reaching a maximum value of 77.14 MPa at 3.5 percent nano-silica. Field Emission Scanning Electron Microscopy (FESEM) confirmed matrix densification and refinement of the interfacial transition zone (ITZ) in nano silica modified mixtures, supporting the observed strength gains. Single-fiber pull-out tests revealed that nano silica significantly improved average and equivalent interfacial bond strengths. Steel fibers exhibited the most consistent bond improvement, while raffia fibers demonstrated the weakest performance. Longer fiber embedment enhanced bond strength and energy absorption for high-modulus fibers. Equivalent bond strength trends indicated a strong dependency on fiber type and embedment length. Direct tensile tests demonstrated that nano-silica significantly enhanced the tensile strength and ductility of composites. The most substantial improvement was observed in steel fiber-reinforced composites, with cracking strength increasing by 166.7% and ductility by 143.3% at 2.5% NS. Correction factors were proposed to align theoretical tensile predictions with experimental results. Overall, nano silica proved highly effective in improving FRCCs by densifying the matrix, strengthening the fiber matrix interface, and enhancing mechanical performance under tensile loading.