Journal of Civil Engineering Beyond Limits (CEBEL)

Saad Issa Sarsam

The USPV technique provides a rapid and non-destructive testing (NDT) approach for evaluating concrete pavement quality. It is considered sustainable, safe, quick, and accurate since it does not compromise the structural integrity of the concrete after testing. In the present investigation, RCC slab samples were prepared in the laboratory with three different percentages of ordinary Portland cement and two types of aggregates gradation (dense and gap). Beam specimens were obtained from the compacted slab samples and subjected to flexural strength (FS)determination. Specimens were monitored before and after application of flexural stress with the aid of USPV technique, variations in USPV and FS attributable to aggregate gradation and cement content were quantified and empirically modeled. It was concluded that dense graded RCC mixture shows higher USPV than gap graded mixture by (6.1, 3.2, and 0.9) % for mixtures prepared with (10, 12, and 16) percentages of cement content respectively. The FS of dense graded RCC is higher than that of gap graded RCC by (38.4, 34.7, and 18) % for mixtures prepared with (10, 12, and 16) % cement content respectively. The obtained mathematical power regression models with high coefficient of determination can provide a rough guide and be implemented for fast and preliminary estimation of RCC flexural strength within the investigated material ranges of FS of RCC and instant detection of RCC quality.

https://doi.org/10.36937/cebel.2026.11125

Md. Osman Gani Rasel Md Mahabub Rahman Md. Mahfuj Ahmed Sizan

Air pollution, and particularly fine particulate matter (PM₂.₅), poses a significant eco-health threat in Bangladesh. This study estimated the spatiotemporal dynamics of PM₂.₅ concentration for the years 2017 to 2022 over Bangladesh using the daily 1 km resolution GlobalHighPM₂.₅ V1 dataset. After preprocessing, the daily data were pooled to produce maps of mean annual concentrations in the Google Earth Engine (GEE) platform and assess spatial heterogeneity compared with the World Health Organization (WHO) annual guideline value of 5 µg/m³. National mean PM₂.₅ concentrations showed intermediate interannual variability, rising from 6.491 µg/m³ in 2017 to 7.424 µg/m³ in 2018, followed by the annual values of 5.374 µg/m³ (2019), 5.103 µg/m³ (2020), 6.276 µg/m³ (2021) and 5.013 µg/m³ (2022). The percentage of the part of the country above the WHO guideline was 49.7% (2017), 57.3% (2018), 10.2% (2019), 3.1% (2020), 27.5% (2021) and 0.3% (2022) of the target area percent, respectively. Results showed that an average high of 9.64 µg/m³ was present in urban and industrial areas, which also remained polluted hotspots based on spatial analysis for the year 2021. Vehicular emissions, brick kilns, industrial activity, biomass burning, and urbanization are the likely contributors to air pollution according to prior literature. The results highlight the urgent demand for improved air quality management policies and establishing an effective framework that combines satellite-based datasets with cloud-computing platforms to monitor air pollution in data-scarce areas over long periods.

https://doi.org/10.36937/cebel.2026.11131

Md. Harun Ar Rashid Md. Rakib Al Mazzuz Md. Rakib Miah Md. Shafikul Islam

Soils of varying proportions are deposited layer by layer naturally or manmade formations known as multi-layered slopes are a common phenomenon encountered in hill tract regions. A multi-stage slope located at Kutupalong Rohingya Camp in Cox’s Bazar; Bangladesh was considered for the study of slope stabilization with combined reinforcement. Simplified Bishop’s Method and Fellenius method were depicted at each 5ᵒ from 40ᵒ to 60ᵒ slope angle interval with Geo5 software solution. Construction over these regions or development of localization generated a progressive surcharge load at the crest of the slope. The effect of incremental surcharge load on the stability of multi-stage slope was investigated. Pile reinforcement had been proven to be an effective measure of stabilization and hence three pile positions at 2m vertical intervals were analyzed under progressive surcharge loads and its effects were studied to find out the optimal pile position. The optimal pile position improved the stability of the non-reinforced slope by around 42% to 75.5% by Bishop’s method and 47% to 83% by Fellenius method. Study of combined reinforcement carried out by providing anchor support along with pile provided at optimal pile position. The anchor placement position was trialed by three different positions i.e., at each one-third of the slope height (H/3) to find out the most efficient position to support piles. An arrangement of pile-anchor combined reinforcement providing higher factor of safety when subjected to the largest surcharge load was recommended as the optimal remedial measure

https://doi.org/10.36937/cebel.2026.11122