Conference Presentations by Sourav Ray
Proceedings of the 5th International Conference on Engineering Research, Innovation and Education ICERIE 2019, 25-27 January, Sylhet, Bangladesh, 2019
The aim of this investigation is to use coconut fibers as a reinforcing factor for concrete (made... more The aim of this investigation is to use coconut fibers as a reinforcing factor for concrete (made of 70% natural aggregates and 30% recycled concrete aggregates) and observe the positive and negative effects in compressive strength and split tensile strength. The compressive and split tensile strength values were optimized using Design Expert software to find the suitability of coconut fiber reinforced recycled concrete and compared to the concrete made with recycled concrete aggregate. The test results showed that the concrete sample having AR75 at 2% gave compressive strength 27.35 MPa at 28 days and which increased by 78.0%. It also gave tensile strength values 4.00 MPa at 28 days which increased by 73.16% respectively. These strength values were compared with the strength values of 0% coconut fiber concrete.
Papers by Sourav Ray
Journal of King Saud University - Engineering Sciences
Journal of Building Engineering
International Journal of Structural Engineering
International Journal of Sustainable Materials and Structural Systems
SN Applied Sciences
In this study, the influence of twelve concrete mix ratios and two rebar grades on the cost of 3,... more In this study, the influence of twelve concrete mix ratios and two rebar grades on the cost of 3, 7, 12 and 20 story RC building frames was investigated. Cylindrical concrete specimens having different mix ratios (by mass) were prepared with Ordinary Portland Cement and locally available fine and coarse aggregates. The compressive strength of concrete was tested on the 28th day of curing. A linear equation is proposed to predict the compressive strength of concrete keeping it as the function of the percentage of cement and the ratio of coarse and fine aggregate. Based on the compressive strengths obtained from different mix ratios, buildings of the same model were designed using the ETABS, as per the provision in Bangladesh National Building Code-2006 (which has a great similarity with the latest ACI code). Also, each building was evaluated individually for the two most conventionally used rebar grades. Therefore, in total 96 buildings were evaluated to obtain the total materials cost for each of the mix ratios and rebar grades. It was seen that (1) for low rise building the cost becomes lower when the lower strength concrete is used, (2) for medium to high rise building high strength concrete can be considered cost-efficient, (3) the mix ratios having a higher coarse aggregate/fine aggregate ratio tends to increase the cost, and (4) 500 MPa rebar was found cost-effective compared to 400 MPa rebar.
SN Applied Sciences
In Gutenberg-Richter (GR) earthquake frequency magnitude relationship the b-value plays an import... more In Gutenberg-Richter (GR) earthquake frequency magnitude relationship the b-value plays an important role and is required for the seismic hazard analysis of any region. In this study, both the Gumbel's extreme distribution and the GR methods are used to estimate the b-value for Sylhet region of Bangladesh. Due to the geological location this region is the most seismically vulnerable area of the country. Sylhet region is situated on the south eastern part of the Dauki fault. The frequency of seismic activity at the Dauki fault zone has lessened after the great Indian earthquake that occurred in 1897. Therefore, energy may be stored in this fault region, which leaves possibilities that Sylhet may encounter an earthquake. The Sylhet region has experienced nearly 184 earthquakes of magnitude ranging from 4 to 7.2 during the last 101 years. In this study, the probability of recurrence of earthquakes of various magnitude has also been investigated using USGS catalogue which has been prepared by taking moment magnitude (M w) as a homogenous magnitude. The least square regression method has been applied to compute the b-value by the GR relationship, which resulted in the b-value to be 0.75. Nevertheless, the regression analysis through Gumbel's extreme value displays a satisfactory result. Further the regression analysis through Gumbel's method estimated the b-value to be 0.91 and using this the earthquake recurrence probability and the return period for different magnitudes have been calculated. From the probabilistic analysis it has been found that the probability of recurrence of an earthquake (R) of M w ≥ 6.5 in 100 years is 85% and its return period (Tr) is 53 years in this region. The earthquake recurrence probability of significant damaging earthquakes affecting Sylhet and their return periods have also been investigated. It has been observed that the probability of recurrence of an earthquake equal or greater than 1885 Bengal earthquake (M w ≥ 7.0) in 100 years is 48.5% in this region and its return period (Tr) is 151 years.
American Journal of Civil Engineering, 2016
Bangladesh is one of the most earthquake prone areas in South-Asia and Sylhet is the most seismic... more Bangladesh is one of the most earthquake prone areas in South-Asia and Sylhet is the most seismic vulnerable region in Bangladesh. Seismic performance analysis is highly recommended to ensure safe and sound building structures for this region. To get better performance from reinforced concrete (RCC) structure, new seismic design provisions require structural engineers to perform both static and dynamic analysis for the design of structures. The objective of the this study is to carry out static and dynamic analysis i.e. equivalent static analysis, response spectrum analysis (RSA) and time history analysis (THA) over different regular and irregular shaped RCC building frame considering the equal span of each frame as per Bangladesh National Building Code (BNBC)-2006. In this study, four different shaped (W-shape, L-shape, Rectangle, Square) ten storied RCC building frames are analysed using ETABS v9.7.1 and SAP 2000 v14.0.0 for seismic zone 3 (Sylhet) in Bangladesh. Comparative study on the maximum displacement of different shaped buildings due to static loading and dynamic response spectrum has been explored. From the analyzed results it has been found that, for static load analysis, effects of earthquake force approximately same to all models except model-1(W-shape).W-shape has been found most vulnerable for earthquake load case. It is also found from the response spectrum analysis that the displacements for irregular shaped building frames are more than that of regular shaped building. The overall performance of regular structures is found better than irregular structures.
The incineration of medical waste (MW) is a significant alternative way for disposal of this cate... more The incineration of medical waste (MW) is a significant alternative way for disposal of this category of waste. Thus nuisance has acknowledged much attention but relatively less attention has been given to bottom ash. Now bottom ash is dumped on the soil which mixes into the soil as diffused pollutant. In this study bottom ash samples were collected from a typical MW incinerator and typical pollutants including heavy metals (Fe, Cr, Cd, Cu, Pb) concentration were examined by following standard extraction and detection procedure. Pollution Load Index, Ecological Risk Index, Enrichment Factor and Geo accumulation Index were applied to assess the level of heavy metal contamination. Co-relation factors of those heavy metals were also established. In our test, the concentration of Cu, Cr and Pb exceeded the tolerable level. The concentration of Cd did not exceed the tolerable level.
In this study a seasonal ARIMA model was built using Box and Jenkins method to forecast long term... more In this study a seasonal ARIMA model was built using Box and Jenkins method to forecast long term rainfall in Sylhet. For this purpose rainfall data from 1980 to 2010 of Sylhet station were used to build and check the model. Rainfall data from 1980 to 2006 were used to develop the model while data from 2007 to 2010 were used to verify the prediction precision. Four basic chronological steps namely: identification, estimation, diagnostic checking, and forecasting were fitted out in developing the model. Validity of the model was tested using standard graphical explanation of residuals given by Box and Jenkins. As a second step of validation, forecasted values of monthly rainfall were checked using actual data series. After completion of necessary checking and forecast observation, the ARIMA(0, 0, 1) (1,1, 1) 12 was found to be the most effective to predict future precipitation with a 95% confidence interval. It is expected that this long term prediction will help decision makers in efficient scheduling of flood prediction, urban planning, rainwater harvesting and crop management.
In this study a seasonal ARIMA model was built using Box and Jenkins method to forecast long term... more In this study a seasonal ARIMA model was built using Box and Jenkins method to forecast long term rainfall in Sylhet. For this purpose rainfall data from 1980 to 2010 of Sylhet station were used to build and check the model. Rainfall data from 1980 to 2006 were used to develop the model while data from 2007 to 2010 were used to verify the prediction precision. Four basic chronological steps namely: identification, estimation, diagnostic checking, and forecasting were fitted out in developing the model. Validity of the model was tested using standard graphical explanation of residuals given by Box and Jenkins. As a second step of validation, forecasted values of monthly rainfall were checked using actual data series. After completion of necessary checking and forecast observation, the ARIMA(0, 0, 1) (1,1, 1) 12 was found to be the most effective to predict future precipitation with a 95% confidence interval. It is expected that this long term prediction will help decision makers in e...
Disposal of stone dust resulting from crushing activities has been become a crucial issue in Bang... more Disposal of stone dust resulting from crushing activities has been become a crucial issue in Bangladesh. Sand is commonly used as a fine aggregate in Bangladesh. This study concentrates on the determination of the strength of mortar and concrete by using mixture of sand and powder sand in various ratios as fine aggregate so as to find an alternative of sand and to minimize and utilize waste. The objective of the study is to establish that the powder sand can be used as an alternative of sand or mixed with sand in making medium grade concrete and mortar where high strength is no required . The study has been conducted in different proportion of sand and powder sand in different mixing ratio for both mortar and concrete. In this study crushed stones are used to make concrete as coarse aggregate. The laboratory tests are made to find the strength for various ratios and then are compared to each other. The result shows that stone powder shows almost equivalent strength as shown by sand ...
Heavy metals such as arsenic (As), copper (Cu), chromium (Cr), Hg, lead (Pb) and cobalt (Co) caus... more Heavy metals such as arsenic (As), copper (Cu), chromium (Cr), Hg, lead (Pb) and cobalt (Co) cause adverse effects on living organisms by their toxic nature. To remove heavy metals, a variety of conventional treatment technologies have been tested which are not economical and user friendly. So, natural remediation method such as phytoremediation is becoming more popular where plants are used. Phytoremediation is a cost effective and eco-friendly method. This paper accounts the study to exercise the phytoremediation potential of the aquatic plant Spirodela polyrhiza for arsenic and copper removal from water. To carry out the study, six plastic bowls each carrying 1 L distilled water were taken where arsenic and copper of known concentration was added for preparing a solution, which contained 1.0, 0.9, 0.7, 0.6, 0.5, and 0.3 mg/L of arsenic and 5.0, 4.6, 4.2, 3.8, 3.4 and 3.0 mg/L of copper. 50 g of S. polyrhiza plant was placed in water of each bowl. The concentration of arsenic and copper in water was measured by spectrophotometer using Silver diethyldithiocarbamate (SDDC) and Bicinchoninate methods, respectively and test was performed for 7 days after placing plants in solution. Gross effective floating period for S. polyrhiza was found 96 h up to initial concentration of 0.6 mg/L to treat arsenic contaminated water and 3.4 mg/L to treat copper contaminated water. The extraction capacity of S. polyrhiza was found more than 80% for all concentration of arsenic and more than 60% for all concentration of copper after 96 h. The removal of arsenic and copper was found to follow the first order kinetics except copper with initial concentration of 5.0 and 4.6 mg/L.
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Conference Presentations by Sourav Ray
Papers by Sourav Ray