Determination of coarse aggregate morphological indices and shape properties by 3d photogrammetry method

Download
2021-4-8
Rashidzade, Isfandiyar
The morphological properties of the aggregatesplaya crucial role in the performance of the pavements. Therefore, thereexist various empirical methods and image-based approaches that directly or indirectly measure these properties. Image-based approaches are majorly classified as two-dimensional (2D) or three dimensional (3D). It has been reported in many studies that the 3D methods capture the overall aggregate morphological and shape properties more accurately than any 2D alternatives. However, the equipment need in the 3D approaches are expensive and processing durations are extensively long. Therefore, this study aimed to develop a practical and inexpensive 3D photogrammetry based method to overcome the need for 3D imaging equipment. This study introduces a detailed guideline including a testing setup and analysis methodology to measure morphological indices (angularity and form indices) and also shape features (volume, surface area, and diameters).Overall 56 aggregates from basalt, dolomite, limestone, perlite, and river gravel sources that retained on1/2”and 3/8”sieve sizes were analyzed utilizing the proposed 3D and traditional 2D methods.Moreover,sensitivity analysis based on triangulation and angle increments were performed to optimize the time and efficiency of the developed algorithm. Consequently, the analysis revealed that the proposed 3D method is capable to accurately determine the shape features and morphological indices.This method can be successfully utilized as a quality control/assurance method by the construction industry.

Suggestions

Preparation and characterization of organoclay-polypropylene nanocomposites with maleic anhydride grafted polypropylene compatibilizer
Yılmaz, Şule Seda; Yılmazer, Ülkü; Department of Chemical Engineering (2011)
The aim of this study was to improve the mechanical properties “Moplen” EP300L which is a heterophase copolymer. Polymer blends and nanocomposites were prepared by melt compounding method in a twin screw extruder. Nanofil® 5 (N5) and Nanofil® 8(N8) were used as the organoclays, and maleic anhydride grafted polypropylene (M) was used as the compatibilizer. The effects of additive concentrations and types of organoclays on the morphology, mechanical and thermal properties were investigated. Organoclay loading...
Investigation of variations in performance properties of asphalt concrete using image-based finite element model
Karakaya, Yalçın; Güler, Murat; Department of Civil Engineering (2022-7-20)
The objective of this study is to evaluate variations in performance properties of asphalt concrete using a two-dimensional image-based finite element model. Two different asphalt mixtures are used in both laboratory tests and in FEM analyses representing different conditions. A flatbed scanner is then used to capture cross-sectional images of the samples and various image processing techniques are applied to prepare the images for FEM. A unique image vectorization method has been developed to transform cro...
Prediction of forming limit curve at fracture for sheet metal using new ductile fracture criterion
Dizaji, Shahram Abbasnejad; Darendeliler, Haluk; KAFTANOĞLU, BİLGİN (Elsevier BV, 2018-05-01)
The application of ductile fracture criteria (DFCs) in numerical analysis of sheet metal forming processes can lead to the accurate determination of the fracture initiation. In this study, a new uncoupled ductile fracture criterion (DFC) has been developed which considers the effects of material parameters on the forming limit curves (FLCs) and can be easily implemented in the finite element codes. Two different constitutive models have been employed with the new DFC in order to evaluate the results obtaine...
Improvement of structural characteristics of composite thin-walled beams using variable stiffness concept via curvilinear fiber placement
Farsadi, Touraj; Bozkurt, Mirac Onur; Çöker, Demirkan; Kayran, Altan (2021-01-01)
This study presents the use of variable stiffness concept via curvilinear fiber placement to achieve improved structural characteristics in composite thin-walled beams (TWBs). The TWB used in the study is constructed in circumferentially asymmetric stiffness (CAS) configuration. The variation of fiber angles along the span and the width of the TWB is included by defining two fiber path functions. A parametric study is performed to investigate the effects of different fiber paths on the structural performanc...
Calculation of the Ν4 (NH4) IR Mode Frequency and the Damping Constant (FWHM) Close to the Phase Transitions in NH4Zn(HCOO)3 and Nd4Zn(DCOO)3
Kurt, Arzu; Yurtseven, Hasan Hamit; Kurt, Mustafa (2018-09-09)
Temperature dependence of the IR frequency and the damping constant (FWHM) of the ν4(1440 cm-1) NH4+and ν4(1084 cm-1) ND4+ modes, are calculated for the metal formate frameworks (MOFs) of NH4Zn(HCOO)3 and ND4Zn(DCOO)3, respectively, by using the experimental data from the literature. By assuming the IR frequency of the ν4 mode as an order parameter, its temperature dependence is calculated close to the phase transition (TC=191 K) in the NH4Zn(HCOO)3 and ND4Zn(DCOO)3 by the molecular field theory. The temper...
Citation Formats
I. Rashidzade, “Determination of coarse aggregate morphological indices and shape properties by 3d photogrammetry method,” M.S. - Master of Science, Middle East Technical University, 2021.