Journal of Civil Engineering Beyond Limits (CEBEL)

Saad Issa Sarsam

Variation of environmental conditions exhibits various modes of failure of asphalt concrete pavement. Under cold environment, the flexible pavement experience cracking and disintegration while under hot environment, the pavement practices rutting. Both environmental conditions can enhance the fatigue life of the flexible pavement. In the present work, the role of the change in the dissipated energy, and flexural stiffness of asphalt concrete on its fatigue life under environmental influence have been investigated. Asphalt concrete mixtures were prepared with its optimum asphalt binder requirements, and then compacted into a slab mold by laboratory roller to a target density. Beam specimens were obtained from the prepared slab samples and tested for fatigue life using three levels of constant strain of (750, 400, and 250) microstrain under dynamic flexural stresses. The specimens were tested at (5, 20, and 30) ℃ environment levels. It was noticed that specimens practicing cold environment exhibit shorter fatigue life as compared with those tested at hot environment. However, the flexural stiffness of the beam specimens decline as the testing temperature rises. Such behavior was further supported with the variation in the dissipated energy among testing environment. It was concluded that higher testing environment declines the flexural stiffness, increases the fatigue life, and changes the mode of failure of asphalt concrete from brittle to plastic mode.

https://doi.org/10.36937/cebel.2023.1872

Andi Yusra Dewi Purnama Sari Fachruddin Fachruddin Popy Farera

Bamboo ropes assembled in parallel and filled with mortar to create a composite structure. This study uses fixed loads and uses the EYM method. The purpose of this study is to investigate how connection strength, maximum load and stiffness values in normal weight concrete. The concrete design 25MPa used for threaded connections with diameters of 6 mm, 8 mm, and length of 40 cm. This study provides a maximum stress analysis of bolted joint strength and joint behavior. In this test, the study yielded a P-max value of 88.25kN at 6 mm diameter and a P min value of 16.87kN at 6 mm diameter for each variation of the sample. The P-Max value for 8 mm diameter is 29.71kN and the P-Min value for 8 mm diameter is 10.1kN. The stiffness values for each variant with a K-Max value of 41.53kN for diameter six and a K-Min value of 0.96kN for diameter six are 1.98kN K-Max value and 1.98kN K-Min value for diameter 8 mm, 0.21kN for diameter eight. The lateral resistance gives the same result of 8.8kN as for the ones melting point model. The maximum value of the pivot strength at 6 mm diameter and 40% load is 41.53kN/mm2. The highest value of the 40% load test with a diameter of 8 mm is 1.98kN/mm2. Two angle variations used in the test: 45° and 60°. The angular change of the sample damaged during the test was 60°, and the sample damage was 8 mm in diameter.

https://doi.org/10.36937/cebel.2023.1873

Atifet Bingöl Avni Çakıcı

Soil pollution is a significant environmental issue with various causes and consequences. Many industrialized and non-industrialized countries are faced with economic and ecological problems due to toxic element contaminations in soil environments. Especially, soils contaminated with toxic metals pose a major environmental and human health problem that needs an effective and affordable technological solution. Phytoremediation is a process that uses plants to clean up contaminated soil, water, or air. It is an environmentally friendly and cost-effective method for mitigating pollution and is often used in situations where traditional cleanup methods are impractical or too expensive. Vetiver grass is a type of perennial grass native to India. It is widely cultivated for various purposes and has several valuable characteristics such as erosion control and soil improvement. In this study, the tolerance of vetiver grass at phytoremediation of boron polluted soil was examined. For this purpose to determine the tolerance of the vetiver plant to boron, B from H3BO3 was applied to the soil at concentrations of 0, 10, 20, 40, 60, 80, 100, 200, 300, 400 mg B/kg. The results showed that the increase in boron concentration applied to the soil negatively affected plant growth and significant losses in plant height and weight and no growth was observed in plants above 40 mg/kg boron concentration.

https://doi.org/10.36937/cebel.2023.1878

zeynep yaman Ehsanullah Sh. Omari

This study proposes that the Lean concept, which focuses on efficient project management and waste reduction, could be optimal for construction practices in Afghanistan. However, there are challenges in transitioning to Lean construction in the Afghan construction industry, including limited access to official training and awareness among project managers and coworkers, a lack of understanding about Lean concepts, reluctance to change due to existing managerial experience, and resistance to new methods. Very few organisations have some knowledge of the lean concept, but that is not adequate for them to implement it; the managers’ experience limits the usage of the lean method within the organisations. Moreover, the data indicated that the lean construction method is negligible. As well as absence of related knowledge and understanding of the lean concept, many organisations showed to be reluctant towards making any change, even if these changes will predominantly increase performance and better the quality and production standards of their organisation. The accumulated data suggests that organisations have resisted the new tools and techniques provided by the lean construction philosophy and in some cases, it is not suitable and applicable to their organisation. The study identifies four major challenges to a successful transition to Lean construction in Afghanistan: the state of war and lack of security, inadequate awareness and acknowledgement of Lean, cultural and human attitudes, and senior management's obligations.

https://doi.org/10.36937/cebel.2023.1870

Mohammad Manzoor

Although historical masonry structures are highly aesthetic, they harbor numerous structural uncertainties. These structures encompass information such as the date of construction, construction methods, material properties, design details and more. They possess diverse identities in various aspects, making the structural assessment of historical buildings a challenging task. Consequently, all historical buildings should be treated with special consideration, and suitable solutions must be devised. In this study, the structural damage causes of the entrance gate of the Harran Grand Mosque (Ulu Cami), which had undergone recent restoration but suffered damage once again during the Kahramanmaraş earthquakes on 6 February 2023 have been investigated. A three-dimensional finite element model of the structure was developed using Abaqus software. In the numerical studies the static as well as non-linear dynamic earthquake analyses were conducted to evaluate the reasons of the collapse of the structure. The structure was subjected to earthquakes from different directions and its compatibility with actual damage scenarios was observed. The study results are presented with contour diagrams of displacement, stress and damage situations. Upon reviewing the numerical findings obtained from the study, it is evident that the actual damage condition of the structure can be reasonably simulated. As a result, it is thought that the earthquake hit the entrance arches from out of plane which caused the collapse. To sum up, by evaluating the damage conditions resulting from such numerical studies, restoration applications can be handled more effectively, ensuring that correct interventions are carried out

https://doi.org/10.36937/cebel.2023.1876