Papers by Keyword: Gradation

Abstract: The use of waste materials as a substitute for natural aggregate has been widely tested in all areas of the construction industry. Yet, there is a lack of study on the suitability of the physical properties of waste material when used as one of the components in track ballast. This study evaluates the suitability of conventional ballast (CB) incorporated with concrete debris (CD) and bottom ash (BA) as track ballast material. To achieve the objective, sieve analysis, shape analysis, specific gravity test, water absorption test, and permeability test were carried out. Furthermore, microscopic analysis was used to validate the presence of voids. The result shows that the waste mixed ballast has a coefficient of uniformity (Cu) in the range of 1.92 to 12, a coefficient of curvature (Cc) in the range of 0.8 to 1.18, fines less than 14 mm account for 0.1 % to 28 %, and the mean size is in the range of 22.5 mm to 27.5 mm. Furthermore, the flakiness ranged from 7.56% to 22.5%, the void ratio was 0.43 to 0.55, and water absorption was 2.86% to 4%. The specific gravity was found to range from 2.30 to 2.77 when the permeability measurement was in between 30 cm/sec to 61 cm/sec. All these promising values of engineering properties exhibit the confidence of a suitable alternative to track ballast materials. Hence, CD and BA waste materials incorporated into conventional ballast have a high potential to exhibit better performance and reduce the dependency on natural aggregate.

Abstract: The high temperature stability of AC-16, AC-13, AC-20 under specimen thickness of 5cm and 6cm is studied through indoor asphalt mixture high rutting test, Through comparison and analysis about experimental data, it is found that the stability of AC-16, AC-13, AC-20 asphalt mixture at high- temperature decreases in turn. It is shown that thickness changes did not affect the change trend of the high temperature stability under gradation change, and the stability of AC-16 at high-temperature is the best, the AC-13 is second and the AC-20 is less.

Abstract: The main purpose of the present work is to determine the optimum gradation direction of an endodontic prefabricated parallel post (EPPP) made of functionally graded material (FGM). To determine the optimum gradation direction of an EPPP made of FGM, the finite element method (FEM) is used. After that, the optimization technique was adopted in order to determine the optimum material gradient for the functionally graded endodontic prefabricated parallel post (FGEPPP). Simulation results indicated that, the optimum gradation direction for the FGEPPP is from up to down, and can be described by using a modified sigmoid function. The effect of varying of the material gradient indexes on the performance of the (FGEPPP) is investigated. Also, stress distributions in all of FGEPPP cases and in homogeneous EPPP case are investigated. The current investigation shows that, the use of the FGM improves the performance of an EPPP.

Abstract: The first aim of asphalt mixture gradation design is moisture resistance and uniformity. In such a case, the high temperature stability and durability is to be improved. In order to improve the moisture resistance level of asphalt mixture ATB-25, and reduce the possibility of moisture damage, the experiment will use the orthogonal method. On this condition, chose 9 group of mixture gradation with two factors and three levels. With marshall experiment and the results analysis we find the relationship in VV, asphalt content and gradation. The maximal and minimum value of VV will be found. The range of moisture damage will be obtained. This research will provide a meaningful reference for ATB-25 gradation design.

Abstract: Strength properties and modulus characteristics were studied through laboratory experiment with different gradation types, different cement content of cement stabilized macadam. Test results show that, in the same conditions of aggregate types, the two important factors that influence cement stabilized macadam road performances are mixture types and cement content. With the improvement of the amount of cement, the mixture strength and modulus of resilience are growing; when we use a certain amount of cement, different types of cement gravel structure show different properties. And frame cement stabilized aggregate exhibit excellent road performance.

Abstract: This paper presents an introduction to the approach to calculation of fractal dimension of SiO₂/UPR granular composites. The porosity of quartz mixture, the density, the optimum amount of unsaturated polyester resin (UPR) and the mechanical properties of the SiO₂/UPR granular composites were tested. The relationship between the four factors and the fractal dimension was analyzed and the relation expressions were obtained by fitting. For the SiO₂/UPR granular composites, fractal theory is not only used for the design of gradation and the optimum amount of UPR, but also for calculating and evaluating the mechanical properties. Research shows that the fractal dimension plays a role of linking the microstructure and the macroscopic properties of the SiO₂/UPR granular composites.

Abstract: High temperature stability of asphalt mixture is one of asphalt pavement major performance which concerns the permanent deformation of the pavement. Four different gradations were used to detect the mixture high temperature stability, dynamic stability or short for rut distortion for regress time was obtained from regression for the data of rutting test, and the test indicates that either of these two indexes can better characterize high temperature stability of asphalt mixture.

Abstract: License plate recognition technology has been widely used with the development of intelligent traffic system, which studies vehicle identification based on digital image processing technology. This paper presents system design and realization of recognition system for license plate. License plate image is preprocessed by gradation and binaryzation at first, then the image noise caused by dirt is filtered by a mean value method. We adopt horizontal and vertical projection method to locate license plate. Character segmentation and recognition are carried out at last. Test result shows that the method presented has good accuracy, quick speed and strong robustness for realtime application.

Abstract: The earth-rock dam on left bank of the head of DJIPLOHO Hydroelectric Power Station adopts the clay core dam. Due to the tropical oceanic climate which is hot and rainy, the soil of clay core wall has high water content. Through the compaction experiment on site, it chooses suitable dry density, formulates reasonable rolling parameters and finally achieves good construction quality, which ensures the construction progress and meets the requirement of engineering. This accumulates valuable experience for the design and construction of same types engineering.

Abstract: The paper illustrates the design theory and method of micro-computer controlling system for batch asphalt mixing equipment in measurement and gradation. Then combined with the practical application, the paper introduces the solution of factors of affecting the quality of asphalt mixture.