ICAR Technical Reports
Permanent URI for this collectionhttps://hdl.handle.net/2152/32838
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Browsing ICAR Technical Reports by Subject "Aggregate tests"
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Item Rapid Test to Establish Grading of Unbound Aggregate Products: An Evaluation of Automated Devices to Replace and Augment Manual Sieve Analyses in Determining Aggregation Gradation(2002-02) Rauch, Alan F.; Haas, Carl T. (Carl Thomas); Browne, Craig; Kim, HyoungkwanSeveral automated devices are commercially available for measuring the gradation of unbound stone aggregates. These computerized machines, which provide a rapid alternative to manual sieving, capture and process two-dimensional digital images of aggregate particles to determine grain size distribution. Five of these automated gradation devices were evaluated for accuracy and performance. Fifteen aggregate test samples, with different size, shape, and mineral characteristics, were used in these tests. To quantify how well the machine results compare with data from standard sieve analyses, the CANWE statistic was developed and used. While the machine data did not match the sieve data exactly, the evaluated devices were found to provide good measures of particle gradation for most samples. These tests also indicate that some machines will give more repeatable results in multiple tests of a given material, while others yield better results when testing different materials. The methodology used in this study is suitable for objectively evaluating the accuracy of other rapid gradation machines for various applications. ICAR Project 503 was undertaken to study rapid, automated methods of determining the grain size distribution of unbound aggregate products. Two technologies were studied in detail: digital image analysis and laser profiling. This report summarizes the evaluation of digital imaging devices, while the second part of the final project report describes the development of a laser scanning device for grading aggregates.Item Rapid Test to Establish Grading of Unbound Aggregate Products: Automation of Aggregate Characterization Using Laser Profiling and Digital Image Analysis(2002-06) Haas, Carl T. (Carl Thomas); Rauch, Alan F.; Kim, Hyoungkwan; Browne, CraigThis final project report describes the development of a laser scanning device for measuring the gradation and other morphological characteristics of unbound construction aggregates. The device is called the LASS, for "Laser-based Aggregate Scanning System." The method of characterizing aggregate particles from three-dimensional (3D) laser profiling required the development of particle segmentation algorithms, particle measurement algorithms, and generalized particle descriptions. With the LASS, true 3D data of aggregate particles are obtained by laser profiling. This data is first transformed into digital images. Second, segmentation and particle measurement algorithms separate the particles and process each particle data individually with the aid of various digital image technologies. Finally, in order to provide a generalized, quantitative, and representative way to characterize aggregate particles, 3D particle descriptors were developed using the multi-resolution analysis feature of wavelet transforms. Verification tests show that this approach can characterize various aggregate properties in a fast, accurate, and reliable way. When implemented, this ability to automatically analyze multiple characteristics of an aggregate sample will lead to reduced labor costs in the laboratory, but more importantly, to better control of the quality of aggregate products. ICAT Project 503 was undertaken to study rapid, automated methods of determining the grain size distribution of unbound aggregate products. Automatic measurement of particle size and shape properties has the potential to overcome problems with manual measurements such as subjectivity, labor intensity, and slow speed. Testing machines that rely on 2D digital image analysis were evaluated as described earlier in Report ICAR 503-2.Item Rapid Test to Establish Grading of Unbound Aggregate Products: Evaluation of Potential Aggregate Grading Technologies(2000-02) Rauch, Alan F.; Haas, Carl T. (Carl Thomas); Kim, Hyoungkwan; Browne, CraigA research study is underway to develop automated methods for rapidly grading aggregates on the production line in a typical aggregate separation or mixing facility. This interim report serves to document preliminary work on this project and presents: (1) A discussion of typical plant layouts, to identify potential sampling locations. The best sampling locations appear to be just after final screening, where sorted material is sent to stockpiles, and just before mixing the final product, where aggregates are fed from either stockpiles or charge bins. (2) A thorough examination of six potential technologies that could be used to rapidly determine particle size. After a critical review and a formal decision analysis, both digital image analysis and laser profiling appear to be equally promising and worthy of additional study. (3) A discussion of our current thinking on how to configure scanning equipment of this kind. By considering innovative methods for presenting aggregate particles to the scanning sensor, the opportunity exists for advancing this technology. An outline of project work planned for the immediate future. Continuing our study of both digital image analysis and laser profiling, we plan to: 1. Conduct a limited, independent evaluation of three commercial particle-sizing machines, which all use digital image analysis. 2. Perform preliminary tests using a laser profiler. 3. Construct a laboratory test bed that can be used to test and evaluate various scanning sensors.