Articles in This Issue
Abstract
Ferrocement is a type of concrete made of mortar with different wire meshes. It has wide and varied applications in addition to its strength and durability. This research aims to combine ferrocement and sustainability, as over time, the consumption of plastics, especially plastic bottles, has increased and has serious negative effects if buried, burned, or chemically analyzed. Therefore, this research aims to benefit from this plastic waste and introduce it into the construction field by using plastic waste fibers in the concrete mixture instead of cement at a rate of 0.5% and 1% by volume. This research studied the mechanical properties of nine samples of ferrocement beams with dimensions of 1200 × 200 × 150 mm3. A longitudinal hole with a diameter of 50 mm was drilled in different places of the beams and filled with lightweight concrete to facilitate the use of the hole in service passes when drilled, with a study of the initial cracking loads and the resulting deflection in addition to the failure modes and the deflection resulting from the maximum load. The results showed an improvement in load resistance with an improvement in deflection at the maximum load, In addition to an increase in the improvement of Toughness and Stiffness of ferrocement beams.
Abstract
This research investigates air quality and environmental conditions at COMSATS University Islamabad Abbottabad Campus and Missile Chock using IoT-based sensors. Sensors were deployed at both sites to monitor PM 2.5 levels, AQI, temperature, humidity, and gas concentrations. Data was collected over specific intervals and analyzed to identify trends and differences. The methodology involved using IoT-based sensors to capture real-time data on environmental parameters and air quality indicators at both locations, i.e., COMSATS University and Missile Chowk. At COMSATS University, PM 2.5 levels consistently fell within the "Good" category, with readings ranging from 11 to 35 µg/m³. AQI values improved over time, dropping from 91 to 2, indicating effective air quality management. Temperature and humidity remained stable, ranging from 19°C to 21.4°C and 57% to 63%, respectively. The MQ-2 sensor said that the gas levels were between 2550 and 3776 parts per million. On the other hand, Missile Chock had higher PM 2.5 levels, which varied from "Moderate" to "Poor," with values between 11 and 139 µg/m³. Initially, the AQI measurements revealed "Moderate" pollution, but with time, they became better and reached "Good." The humidity was between 18% and 20%, while the temperature was between 30°C and 31.5°C. The MQ-2 sensor results showed that the gas levels were generally high, between 3887 and 4159 ppm. The survey shows that major cities like Missile Chock have greater pollution because of people and automobiles. On the other hand, green locations like COMSATS University have cleaner air. We need to always be aware of air pollution and do something about it so that the air quality in cities improves and the health hazards that come with it decrease.
Abstract
Geopolymer concrete is a material manufactured by polymerizing sources of aluminates and silicates like fly ash, metakaolin, slag, zeolite, etc. with an alkaline solution. A study has been undertaken to produce lightweight geopolymer concrete by using waste zeolite particles (zeolite molecular sieve) as aluminates and silicates source and at the same time as lightweight medium. In addition, others three geopolymer lightweight concrete mixes were produced by partially replacing the waste zeolite particles (25% of volume) with sources materials (fly ash type F, fly ash type C and waste zeolite powder. Moreover, the impact of this partially replacement on dry density, compressive strength and permeation characteristics of produced geopolymer lightweight mixes was studied. An alkaline solution of sodium silicate and sodium hydroxide was used in all the investigated mixes as an activator. From the findings, a geopolymer lightweight mix suitable for insulation purposes (density of 1610 kg/m3 and 28 days compressive strength of 5.1 MPa) was successfully produced using waste zeolite molecular sieve. It was found also that the lightweight zeolite particles were uniformly distributed through the produced mixes. Finally, it was found that replacement of 25% of volume of zeolite particles by fly ash (type C) helped in not only enhancing the compressive strength by about 13% but also reducing the water absorption by about 33%.
Abstract
The purpose of this research is to produce a modified SCC that involves the incorporation of expanded polystyrene (EPS) and waste of plastic type (PET). The goal is to minimize the weight of the material while simultaneously improving its brittleness and reducing the environmental impact. The study focuses on two methods for reducing the weight of structural elements by using EPS beads, which create voids through concrete, and the second method is making a hollow through the element. This study included designing and investigating four concrete beams under concentrated static load. The parameters were hollow position and material types. The results showed that the offsetting hollow from the center of the beam enhanced the ductility index by 10% and increased the load capacity by 10%. Adding EPS beads reduce the concrete density by 11.5% and load capacity by 22%. Toughness was improved by using plastic fiber due to the mechanism of crack bridging. The crack pattern had been changed due to the utilization of waste material, and enhancement was observed through experimental tests by making smooth cracks and changing the probability of sudden failure when using GFRP rebars. It was found that the optimal quantity of EPS was 2 kg to produce SCC in accordance with code requirements. No debonding or slip was observed during monitoring, as evidenced by the absence of spalling or cracking around the reinforcement.
Abstract
Land cover assessment is a significant research area in GIS and remote sensing, aiding decision-makers in understanding land use changes' underlying forces and enabling effective actions. In general, Iraqi cities are experiencing severe degradation of agricultural lands due to population growth and residential development, impacting socio-economic and environmental quality. In addition, the deriving forces of transforming the lands from agricultural to other land cover types are not well understood. Research is needed to map and assess agricultural lands for better economic and environmental solutions. The study uses ANN-CA integration to predict agricultural land changes in Babil province, central Iraq. The CNN model achieved the highest accuracy, with a total land cover transformation of 2143.1 square kilometres between 2000 and 2020. the overall accuracy was 0.95, 0.93, and 0.90 based on images captured in 2020, 2000, 2010) respectively. This methodology is considered an efficient tool for monitoring agricultural lands and developing development plans in Iraq.
Abstract
Foamed concrete (FC) is a type of lightweight concrete characterized by a high void space ratio and cementitious binders. In this research, the fresh and mechanical properties of fiber-reinforced modified foamed concrete (made with fly ash, silica fume, and superplasticizer) with a density of 1300 kg/m³ were studied. Carbon fibers of different lengths (12 mm, 20 mm, and 28 mm) were introduced in two ways: as single fibers (12 mm) and as hybrid fibers combining lengths of 20 mm and 28 mm.
The results showed that the compressive and split tensile strengths increased by approximately 43% compared to the control mix (modified with additives) when using a single fiber of 12 mm at a volume proportion of 0.4%. In contrast, using hybrid fibers resulted in increases of about 65% and 66% in compressive and split tensile strengths, respectively. When compared to the single fiber method, the hybrid approach improved compressive and split tensile strengths by about 15% and 16%, respectively.
Abstract
This study investigates the seismic performance of a nine-storey reinforced concrete building located in Seismic Zone 3, focusing on the effectiveness of viscous dampers in enhancing structural resilience. With increasing seismic risks, the integration of damping systems has become critical for mitigating vibrations and improving building safety. The research evaluates four configurations: a fixed-base building with no dampers, buildings with corner dampers featuring uniform and varying force capacities, and a building with middle dampers. The Equivalent Static Load (ESL) and Response Spectrum study (RSA) methods are used in the ETABS 2021 research to look at important factors such the natural period, storey stiffness, storey drift, storey displacement, and overturning moments. These steps are based on the UBC 97 criteria. The results show that viscous dampers do assist structures stay standing during earthquakes. Buildings with corner dampers that could handle different amounts of stress had a natural period that was 37.5% shorter. This means that they were stiffer and could respond to seismic shocks faster. The storey's stiffness went down by 16.7%, and the periods of overturning went down by 5.7%. This shows that the dampers did a great job of getting rid of energy. Also, the maximum storey displacement and drift were 41.6% and 48.14% lower than in the fixed-base model, respectively. These figures show how important it is to put dampers in the right places, especially at corners where the force capacity changes, to make buildings more resistant to earthquakes. The study's conclusion is that viscous dampers make multi-story structures in moderate seismic zones much safer by making them less likely to break and improving how effectively they perform. This study gives engineers and designers important information that makes them desire to use current dampening technologies in tall buildings to make them safer during earthquakes.
Abstract
Composite beams, made up of a concrete slab and steel in the IPE steel section, are commonly used in bridges and buildings. Their main function is to enhance structural efficiency by merging the compressive strength of concrete with the tensile resistance of steel, thereby improving overall stiffness, ductility, and load-bearing capacity. This study offers an extensive review of the flexural behavior of steel-concrete composite beams, focusing on the interplay of concrete strength, shear connector types, and interaction levels in determining structural performance. It integrates experimental and numerical research to analyze critical parameters, including load-deflection behavior, shear transfer efficiency, and crack propagation at the steel-concrete interface. The study emphasizes the effect of concrete compressive strength, particularly in ultra-high-performance concrete (UHPC) and lightweight concrete, on stiffness, ductility, and load-bearing capacity while reducing self-weight and enhancing sustainability. The study revealed that fully bonded shear connectors, using CFRP sheets and welded plates, enhance flexural capacity and stiffness. In contrast, partial bonding or pre-debonding reduces performance due to crack propagation. Indented and hot-rolled U-section connectors enhance interaction and minimize slip, while uniform distribution of shear connectors optimizes load capacity and stiffness. Lightweight concrete decreases slab weight without compromising performance, and high-performance materials such as ECC, SFRC, and UHPFRC improve strength and ductility. Numerical modeling, particularly finite element methods, and higher-order beam theories validate experimental results, providing accurate tools for predicting structural behavior under various loading and environmental conditions.