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