http://suspace.su.edu.bd/handle/123456789/1633 2026-06-03T08:21:28Z http://suspace.su.edu.bd/handle/123456789/2858 Comprehensive Physico-Chemical Assessment of Surface Water Quality in Hatirjheel Lake, Dhaka, Bangladesh. Sadmani, Nafiz; Hossain, Al-Amin; Ali, Md. Sifat; Sakib, S M Nazmuz; Rahman, Rayhan Abdur; Amran, Shah Rapid and largely unplanned urbanisation has resulted in severe pressure on surface water bodies in Dhaka, Bangladesh. Hatirjheel Lake, situated in the heart of the city, is simultaneously a flood-retention basin, a hydraulic conveyance link, and a major recreational space. This paper presents a detailed yet compact physicochemical assessment based on primary data for three surface-water sampling locations in Hatirjheel, collected in September (the late monsoon/post-monsoon period). The lake water was analysed for pH , temperature, biochemical oxygen demand ( BOD_5 ), chemical oxygen demand (COD), dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDS) and total hardness, following Standard Methods for the Examination of Water and Wastewater. In addition, pH data were available for six samples collected in September 2025 and October 2025, allowing a limited two season comparison. Urban lakes in rapidly growing megacities are often under severe pressure from untreated wastewater, storm runoff and intense human use. Hatirjheel Lake, located in the centre of Dhaka, Bangladesh, is a key element of the city’s drainage and recreation system but has been repeatedly reported as degraded in terms of water quality. In this study, surface water samples were collected from three locations in Hatirjheel during September, and pH data from a previous February survey were also considered. Physico–chemical parameters including pH, temperature, biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), electrical conductivity (EC), total dissolved solids (TDS) and hardness were analysed following standard methods. The results show that pH (7.5–8.0) remained within the permissible range of the Bangladesh Environment Conservation Rules (ECR’97), while EC, TDS and hardness were moderate. However, BOD and COD substantially exceeded national guideline values, and DO at some points dropped below the recommended minimum, indicating organic pollution and potential stress on aquatic biota. The findings are consistent with earlier studies that highlighted the impact of combined sewer overflows and urban runoff on Hatirjheel water quality. The paper concludes with recommendations for improved sewer management, regular monitoring and integration of water quality considerations into future lake management plans. 2026-01-10T00:00:00Z http://suspace.su.edu.bd/handle/123456789/2857 Comparative Analysis Of The Structural Response of A G+8 Storied Building With Varying Shear Wall Placements Using ETABS. Hamim, Abu Darda; Al-Amin, Md.; Rasid, Md. Mamunur; Mondol, Hridoy This study presents a comparative analysis of three structural building models subjected to seismic and wind load conditions. The objective is to evaluate their performance with respect to interstorey drift limits, total sway limitations, and overall structural efficiency in accordance with applicable code requirements. Each model was analyzed using ETABS to obtain lateral displacement and drift responses under EQx, EQy, Wx, and Wy load cases. The results show that Option -2 provides superior performance, satisfying both drift and sway criteria for all load combinations. In contrast, Option -1 fails to meet the drift and sway requirements in the EQx direction, indicating comparatively low lateral stiffness. Option -3 performs better than Option -1 but fails the sway limit in the EQx case, demonstrating the need for additional stiffness enhancement. Among the three, Option -2 not only ensures structural safety and full code compliance but also proves to be the most economical solution, offering optimized material usage while maintaining adequate lateral resistance. This study concludes that Option -2 represents the most effective and efficient structural configuration for the building under the evaluated loading conditions. 2026-01-10T00:00:00Z http://suspace.su.edu.bd/handle/123456789/2856 Comparison of Compressive Strength by Partial Replacement of Sand Using Wood Powder and Rice Husk Islam, Md. Rafiqul; Haque, Md. Asadul; Naim, Alfarabi; Sumi, Sumaiya; Ali, Md. Yeakub The rapid depletion of natural river sand and the increasing generation of agricultural and industrial waste have encouraged researchers to explore sustainable alternative materials in concrete production. This study investigates the effect of partial replacement of fine aggregate (sand) with wood powder and rice husk on the compressive strength of concrete. Concrete was prepared with partial replacement of sand at 0%, 5%, 10%, and 15% by wood powder and rice husk. A total of concrete specimens of size 100 mm diameter and 200 mm height cylinder were cast and tested for compressive strength at 7 and 28 days of curing in accordance with ASTM standards. Partial replacement of sand with wooden husk, the compressive strength improved at 5% replacement compared to the control mix. Partial replacement of sand with rice husk showed 10% rice husk replacement produced the highest compressive strength. This research presents an experimental study on the comparison of compressive strength of concrete by partial replacement of fine aggregate (sand) using wood powder and rice husk. The increasing demand for natural sand and the environmental issues associated with agricultural and industrial waste disposal have encouraged the use of alternative materials in concrete production. The 10% rice husk replacement exhibited the highest compressive strength among all mixes, achieving 3212.52 at 7 days and 3642.00 at 28 days. Concrete containing 5% wood powder showed improved compressive strength compared to the control mix, with values of 2773.44 at 7 days and 3375.42 at 28 days. A comparison between wood powder and rice husk indicates that rice husk performs better than wood powder as a partial replacement of sand. The maximum compressive strength was obtained with 10% rice husk replacement, particularly at 28 days of curing. 2026-01-10T00:00:00Z http://suspace.su.edu.bd/handle/123456789/2855 Study on Salf Compacting Using Admisture Ahmad, Md. Eftaker; Khan, Md. Shakhawat Hosen; Anik, Md. Imran Hosen; Hasan, Md Riyajul Self-compacting concrete using admixture is a specific type of concrete that can flow only by its own weight and can fill any space while keeping its homogeneity. This work summarizes the experiments for evaluating the performance of self-compacting concrete including slump flow tests as well as the recent achievements of the fresh and hardened properties of self compacting concrete such as slump flow, segregation resistance, compressive strength and tensile strength. Also, the previous researches of durability is surveyed including sulfate resistance, inner frost resistance, freezing and thawing. The effect of dosage amount of water binder ratio, water cement ratio and super plasticizer on the properties of self- compacting concrete are revealed based on the survey of previous literatures. Particular emphasis is placed on the availability and economic effectiveness of partial replacement of certain amount of cement by mineral admixtures, ordinary Portland cement. 2025-12-23T00:00:00Z