Journal of Civil Engineering Beyond Limits (CEBEL)

Saad Issa Sarsam

Recycling of aged AC mixture is a sustainable process used to prolong the useful life of the AC pavement. In the present work, Reclaimed Asphalt Pavement (RAP) was obtained from the in-service field pavement and recycled with a mixture of binder and carbon black (CB). Laboratory specimens of Marshall size were prepared from both RAP and recycled mixtures. Part of AC specimens were subjected to (MD)process, then practiced the DITS at (25 and 40) °C environment at constant stress level of 138 kPa in the pneumatic repeated load system (PRLS) with constant loading frequency of 60 cycles per minute. The dynamic loading sequence for each cycle is 0.1 seconds of load duration and 0.9 seconds of rest period. The permanent microstrain (PM) and FN were recorded before and after the MD. At 25° C environment, the MD process exhibited a decline of FN by (80, and 72.5) % for RAP and recycled mixtures respectively. However, in the 40° C environment, the MD process exhibited a decline of FN by (75, and 33) % for RAP and recycled mixtures respectively. Before the MD process, the increment of testing temperature from (25 to 40) °C exhibited decline in FN of AC mixtures by (40, and 62.5) % for RAP and recycled AC mixtures respectively. The recycling index after practicing MD is higher than before MD for FN and PM. Recycling index increases at higher testing temperature of 40 °C as compared to that at 25 °C for PM regardless of testing condition.

https://doi.org/10.36937/cebel.2026.11135

Md. Harun Ar Rashid Kaniz Fatema Abhishek Sharma Md. Azaharul Islam Raju

Safe drinking water is essential for good health. But overgrowing population, geological formation, climatic change, soil erosion, pesticide & fertilizer application, and urbanization are responsible for the pollution of water and variation of the quality parameters of water. This study deals with the suitability of groundwater quality in four upazilas in the Dinajpur district, Bangladesh. In Dinajpur the major source of drinking water is provided by hand-pumping shallow tube wells. 32 water samples from those upazilas were collected (eight from each upazila) for laboratory testing. The important physicochemical parameters, such as temperature, pH, electrical conductivity, total dissolved solids, calcium, magnesium, hardness, bicarbonate, alkalinity, nitrate, and bacteriological parameters, such as total bacteria count, fecal coliform, and Escherichia coli were assessed. Then the testing data were in comparison with the World Health Organization (WHO) & Bangladesh Standards (BDS). The comparison showed that the water was suitable for daily use for the people according to standards. Physiochemical parameters were within the standard level except pH which was low in Dinajpur Sadar, hardness exceeded the limit according to WHO in Biral and Dinajpur sadar upazilas. In Biral, the concentration of magnesium exceeded the standard limits, and nitrate values were exceeded in all upazilas according to BDS. All the samples are free from microbial contamination. In addition, continuous monitoring of the chemical parameters of water is needed for its use in Dinajpur district, Bangladesh.

https://doi.org/10.36937/cebel.2026.11124