http://103.99.128.19:8080/xmlui/handle/123456789/1 All collections of C.E. 2026-09-13T19:50:44Z http://103.99.128.19:8080/xmlui/handle/123456789/583 STORM SURGE INUNDATION MODELLING FOR AMPHAN IN BANGLADESH PART Chakma, Pollen; ID:, 17MCE025P During a Cyclone storm surge related forecasting and warnings in Bangladesh are provided by Bangladesh Meteorological Department (BMD) by giving forecasting and warning of the expected storm surge height during a cyclone. This forecasting does not give any forecasting regarding areas that might be inundated due to the storm surge. This study focuses on developing a storm surge inundation model using Delft3D using current state of the art in storm surge inundation modelling. This research is based on the super cyclone Amphan, which made landfall on May 20, 2020, across the Sundarbans from the west Bengal-Bangladesh coast. Its wind speed ranged from 155 to 165 kmph with gusts up to 185 kmph. At first the tide model is developed. Then after the calibration and validation of the tide model it is run using atmospheric forcing generated from the cyclone model. Cyclone model is run by using IMD and JTWC best track data of cyclone Amphan. Then calibration and validation of the cyclone model shows that the pressure field and wind filed data produced using JTWC best track data shows better R2 and NSE values as compared to IMD. Due to this reason pressure field and wind field data produced using JTWC best tack data is used to force the storm surge inundation model to simulate cyclone Amphan. Then water levels at fours BIWTA water level stations are calibrated and validated. Finally inundation scenario is also compared with two inundation maps for the validation of the inundated area produced by the storm surge inundation model. One is produced by NAWG by survey during Ampahn and another one is inundation map produced using Sentinel-1 SAR images during Amphan. There are some findings related to challenges and different aspects in different stages of storm surge modelling in a data scarce region like Bangladesh that will help researchers to help storm surge inundation related studies in future A Master of Science (M.Sc) Thesis in Civil Engineering (CE) Department at Chittagong University of Engineering and Technology (CUET). 2025-04-29T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/578 Effectiveness of Nano Silica Extracted from Rice Husk Ash (RHA) in Cementitious Media Nila, Nadira Islam; ID:, 22MCE009P The use of concrete is rapidly increasing worldwide, primarily harming the environment due to its primary component, cement, which accounts for roughly 8% of global CO2 emissions. Hence, exploring sustainable alternatives is crucial. Extracted nano-silica (NS) from rice husk ash is gaining interest as a sustainable construction material. In this study, RHA and extracted SP and NS from RHA were characterized comprehensively at pH 3 and pH 10 to evaluate their suitability for application in cementitious media. By utilizing laser particle sizing, scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence (XRF) techniques, the chemical composition, physical characteristics, and microstructure of these binders were examined. The setting time, soundness, autoclave expansion, workability, microstructure, flexural strength, compressive strength, and durability of RHA/SP/NS blended mortar and concrete were assessed. Setting time increased with RHA and SP replacement but was significantly reduced with NS due to early hydration, resulting in early strength development. RHA, SP, and NS blended mortars showed better flexural and compressive strength than the control mix due to higher C-S-H formation. With 2.5% RHA, 10% SP, and 5% NS replacement, maximum strength and better durability were observed in the mortar. At a constant w/b ratio, the compressive strengths found were 59.2 MPa, 60.8 MPa, and 56.2 MPa after 90 days of curing. RHA increased drying shrinkage slightly. However, SP and NS reduced it and improved sulfate resistance at later stages of the curing process. RHA increased the water absorption rate in mortar, whereas adding SP and NS significantly decreased it. On the other hand, in concrete, 7.5% RHA/SP/NS achieved the maximum strength (31.7 MPa, 34.1 MPa, and 33.7 MPa, respectively) and exhibited better durability performance. By increasing the packing density of concrete and reducing porosity, the compressive strength of RHA/SP/NS blended concrete increased significantly, providing better chloride resistance than the control sample. The findings suggest that RHA, SP, and NS have potential as alternative construction materials. A Master of Science (M.Sc) Thesis in Civil Engineering (CE) Department at Chittagong University of Engineering and Technology (CUET). 2025-07-21T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/577 FLEXURAL STRENGTH BEHAVIOUR OF STEEL FIBER REINFORCED CONCRETE BEAM Ahmed, Md. Iftakhar; ID:, 13MCE023P Cement concrete is the most utilized construction material globally. Its extensive use can be attributed to its ability to take any shape. Cement-based concrete is prone to microcracking, exhibits minimal tensile strength, possesses low ductility, and exhibits limited crack resistance. These factors combine to cause brittle concrete failure. Modern civil engineering projects must meet certain durability and structural requirements. Every structure has a specific function and conventional cement concrete must be adapted to these requirements. According to research, adding different types of fibers to concrete in a certain amount can improve the mechanical properties, serviceability and longevity of structures. Currently, a significant characteristic of steel fiber concrete (SFRC) is its exceptional resistance to crack initiation and propagation. The main goal of the research is to predict how an SFRC beam will behave in terms of flexural strength. Steel fibers mixed into concrete were used to cast 180 prisms (100 x 100 x 500 mm) and 360 cubes (100 x 100 x 100 mm). This study modifies the fiber content of 1%, 1.5% and 2% with different aspect ratios (50, 60 and 70) in concrete to investigate the influence of steel fibers on the strength of M30 grade concrete. To examine the impact of steel fibers, tests for compressive strength, flexural strength, and splitting tensile strength were conducted. The overall results indicate that mechanical strength development can be effectively achieved with steel fiber concrete with 1 mm diameter, aspect ratio of 70 and 1.5% steel fibers. A Master of Science (M.Sc) Thesis in Civil Engineering (CE) Department at Chittagong University of Engineering and Technology (CUET). 2024-10-28T00:00:00Z http://103.99.128.19:8080/xmlui/handle/123456789/562 MECHANICAL AND FRACTURE PROPERTIES OF REINFORCED CONCRETE USING STEEL INDUSTRIAL SLAG AND GGBS AS PARTIAL REPLACEMENT OF CEMENT Uddin, A.S.M Nazim Concrete is an essential building material that is always being improved to satisfy the needs of modern infrastructure while increasing environmental sustainability. This study evaluates the mechanical and fracture properties of concrete using the addition of fiber and the partial replacement of cement with industrial by-products such slag and Ground Granulated Blast Furnace Slag (GGBS). Five concrete mix combinations were used according to the mix design by replacing cement content with the ladle slag, GGBS and fiber at various percentages in the concrete mix. The control mix namely Mix-1 was 100% cement content, whereas 10% ladle slag and 30% GGBS has been replaced with cement in the Mix-2 and Mix-3 respectively. Fiber was used in the Mix-4 and Mix-5 with the same ingredients of Mix-3 by 0.05% and 0.10% of concrete volume respectively. It was observed Mix-1 achieved maximum compressive strength whereas a decrease of 4% and 16% in Mix- 2 and 18% and 22% in Mix-3 at 7 and 28 days. The results showed that the GGBS improved the compressive strength compensating for the decrease in cement content to some extent. The results also indicate that the compressive strength of Mix-4 increased by 4% with the addition of 0.05% fiber but decreased by 6% in the Mix-5 when 0.10% fiber was used comparing to the Mix-3. Thereafter the only difference between Mix-3 to Mix-5 is the amount of fiber content used in the mix, which implies that, the addition of fiber improved the strength but for the uses of excessive amount of fiber does not improve strength rather decreases the strength. Ladle slag, GGBS, and fiber improved flexural strength (MOR), and MOR increases by as high as 48% for Mix-5 over the control Mix-1. The fracture energy Gf which represents the amount of energy needed for the formation of cracks in the concrete surface. In addition of 0.05% and 0.10% fiber in the Mix-4 and Mix-5 enhancing the Gf values by 6% and 45% respectively but reduction of cement content by 40% in the Mix vi 3, it’s Gf value decreases by 54%. Which implies that fibers significantly improved the Gf capacity and on the other hand, reduction of cement content decreased the fracture energy values. The fracture energy Gf values has been obtained in the range of 80-175 N/m from the all mix combination where control sample Mix-1 has achieved the highest value. The measure of material’s ability to prevent an unstable fracture or crack is called stress intensity factor Kic. In this study highest Kic is obtained at control Mix-1 indicating above mix has maximum ability to resist the growth of the cracks. The Kic values are gradually decreases by 8% and 54% for the reduction of 10% and 40% of cement in the Mix-2 and Mix-3. Addition of fiber in the concrete mix significantly enhanced the fracture toughness Kic value by 39% and 33% in the mix combination Mix-4 and Mix-5. The range of Kic values has been evaluated 0.82-1.78 MPa m0.5 in this study. A Master of Science (M.Sc) Thesis in Civil Engineering (CE) Department at Chittagong University of Engineering and Technology (CUET). 2025-03-06T00:00:00Z