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Full-Text Articles in Civil Engineering
Restrained Shrinkage Of Fly Ash Based Geopolymer Concrete And Analysis Of Long Term Shrinkage Prediction Models, Md R. Islam, Mahbub K. Ahmed, Hosney Ara Begum, Erez N. Allouche
Restrained Shrinkage Of Fly Ash Based Geopolymer Concrete And Analysis Of Long Term Shrinkage Prediction Models, Md R. Islam, Mahbub K. Ahmed, Hosney Ara Begum, Erez N. Allouche
Journal of the Arkansas Academy of Science
The research presented in this manuscript describes the procedure to quantify the restrained shrinkage of geopolymer concrete (GPC) using ring specimen. Massive concrete structures are susceptible to shrinkage and thermal cracking. This cracking can increase the concrete permeability and decrease the strength and design life. This test is comprised of evaluating geopolymer concrete of six different mix designs including different activator solution to fly ash ratio and subjected to both restrained and free shrinkage. Test results obtained from this experimental setup was plotted along with the available empirical equation to observe the shrinkage strain of GPC and a model was …
Selection Of A Realistic Viscous Vortex Tangential Velocity Profile For Computer Simulation Of Vortex-Structure Interaction, M. N. Strasser, R. P. Selvam
Selection Of A Realistic Viscous Vortex Tangential Velocity Profile For Computer Simulation Of Vortex-Structure Interaction, M. N. Strasser, R. P. Selvam
Journal of the Arkansas Academy of Science
Structure loading by vortices is a relevant phenomenon in numerous fields of engineering significance. Computer modelling is a powerful tool that can be used to study the loading produced on structures by impacting vortices. Realistic simulation of vortex-loading of structures necessitates the use of a realistic vortex tangential velocity profile (TVP). The present study compiles measured TVPs from various types of experimentally-produced vortices as well as real-world tornado and hurricane vortices. The measured TVPs are compared with commonly-used, analytical TVPs. Analytical TVPs that realistically represent the range of measured TVPs are identified and selected for use in future computer simulation …
Computer Modeling Of Tornado Forces On A Cubic Building Using Large Eddy Simulation, R. Panneer Selvam, Paul C. Millett
Computer Modeling Of Tornado Forces On A Cubic Building Using Large Eddy Simulation, R. Panneer Selvam, Paul C. Millett
Journal of the Arkansas Academy of Science
A tornado changes its wind speed and direction rapidly; therefore, it is difficult to study the effects of a tornado on buildings in a wind tunnel. The status of the tornado-structure interaction and various models of the tornado wind field found in literature are surveyed. Three dimensional computer modeling work using the turbulence model based on large eddy simulation is presented. The effect of a tornado on a cubic building is considered for this study. The Navier-Stokes (NS) equations are approximated by the finite difference method and solved by an implicit procedure. The force coefficients are plotted in time to …
Field Interpretation Of Latitude And Longitude In Arkansas: A Portable Coordinate Projection, William R. Teague
Field Interpretation Of Latitude And Longitude In Arkansas: A Portable Coordinate Projection, William R. Teague
Journal of the Arkansas Academy of Science
Two- and three-dimensional coordinate systems are fundamental to most quantitative mapping applications. The Geodetic, Universal Transverse Mercator (UTM),and State Plane systems have traditional roles in various science, surveying, and government agency engineering applications. The coordinates of three-dimensional Geodetic system are latitude, longitude, and height above ellipsoid (HAE).Because of its ability to cope with the intrinsically three dimensional character of the earth's surface, the Geodetic system is capable of supporting precise relative positioning and very high accuracy computations of distance between any two positions on or near the earth's surface. The two-dimensional UTMand State Plane systems are extremely useful for the …
Construction Resource Allocation Using A Genetic Algorithm, Siripong Malasri, Jennifer R. Martin
Construction Resource Allocation Using A Genetic Algorithm, Siripong Malasri, Jennifer R. Martin
Journal of the Arkansas Academy of Science
A proper allocation of limited resources (men, machines, materials, and money) is critical in a construction project. Traditionally, resource allocation problems have been solved using methods in operations research (OR), such as mathematical programming. In recent years, genetic algorithms (GA) have emerged as an effective optimization methodology. One major advantage of the GA approach over the OR approach is that the GA approach is universal for various types of optimization problems, unlike the OR approach which varies depending on the types of problems at hand. This paper shows an application of GA to a resource allocation problem in the construction …
Concrete Beam Design Optimization With Genetic Algorithms, Siripong Malasri, D. A. Halijan, M. L. Keough
Concrete Beam Design Optimization With Genetic Algorithms, Siripong Malasri, D. A. Halijan, M. L. Keough
Journal of the Arkansas Academy of Science
This paper demonstrates an application of the natural selection process to the design of structural members. Reinforced concrete beam design is used as the example to show how various chromosomes representing a design solution can be formulated. Fitter chromosomes (or better solutions) have a better chance of being selected for cross over; this in turn creates better generations. Random mutation is used to enhance the diversity of the population. The evolution progresses through several generations, and the best solution is then used in the design. The method gives reasonable results, but sometimes a local (as opposed to the global) optimized …