Experimental and numerical investigation of shrinkage mechanism of plain and reinforced concrete members

Download

12625871.pdf

Date

2020-9

Author

Albostan, Utku

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

318
views

215
downloads

Concrete shrinkage is a long-term process causing a reduction in the volume of a concrete member. In the majority of the concrete models, shrinkage is considered as a uniform unrestrained shortening through the longest dimension, but in reality, due to the existence of aggregates and reinforcing bars, which restrains the shrinkage deformations, a non-homogeneous strain distribution occurs within the member. In order to measure such non-homogeneous deformations on an entire surface, digital image correlation (DIC) method is a good candidate. In the conventional DIC method, high-speed video cameras are utilized, but their measurement sensitivity may not be sufficient to detect shrinkage induced deformations in the order of m. Thus, a novel DIC based measurement method for measuring drying shrinkage deformation on concrete surfaces is proposed that utilizes high-resolution images acquired by DSLR cameras. The validity of the proposed method is first tested on three different experimental studies. Then, shrinkage deformations of several concrete beams with and without reinforcement under free and restrained boundary conditions are measured with the proposed method for two months at a new experimental set-up designed for such experiments. This way, non-homogeneous strain distribution on the entire surface due to aggregates and reinforcing bars are obtained. In order to numerically mimic the shrinkage behavior of plain and reinforced concrete members, a new mesoscale modeling and calibration approach is also developed that is based on overlapping lattice method. The validity of this new approach is tested by comparing the numerical results with the DIC measurements of the shrinkage experiments. Numerical results demonstrate that the proposed numerical approach has the capability of modeling shrinkage deformations of plain and reinforced concrete members.

Subject Keywords

Concrete shrinkage, Digital image correlation, Mesoscale concrete model, Overlapping lattice model, Dijital görüntü korelasyonu, Meso-ölçekli beton modeli, Örtüşen kafes yöntemi, Betonun büzüşme mekanizması

URI

https://hdl.handle.net/11511/69245

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Dynamic response analysis of the machine foundations on a nonhomogeneous soil layer Aşık, Mehmet Zülfü (1999-01-01) Real modulus of elasticity of the soil usually increases with the depth of the soil due to the increase in overburden pressure. Therefore, incorporation of the effect of the soil inhomogeneity in the formulation to obtain the response of the machine foundations is an important and a necessary step. In this paper, equations that govern the dynamic behavior of the machine foundations and consider the inhomogeneity of the elastic foundation, particularly for Gibson type soil are derived by using variational pr...
Determination of the Tensile Strength of Different Fiber Reinforced Concrete Mixtures Ardoğa, Mehmet Kemal; Alam, Burhan; Yaman, İsmail Özgür (null; 2016-09-21) Enhancing the tensile performance of concrete is the main advantage when fibers are added to this type of building materials. This improvement is usually measured through indirect methods like bending or split-tensile tests, in a way similar to normal concrete due to the absence of a standard tensile test for such purpose. Naturally, this type of tests does not determine the real tensile strength of the fiber reinforced concrete. Hence an important parameter, that is needed in modelling and designing proces...
Simulation of damage propagation on massiveconcrete structures, the overlapping lattice model v.s.The finite element approach Soysal, Berat Feyza; Arıcı, Yalın; Binici, Barış; Tuncay, Kağan (2017-10-11) The increase in the computational power enables the performance based assessment of very large structures like concrete gravity dams. These assessments are usually carried out with the traditional finite element tools. The continuum based formulation of these analyses in the absence of costly re-meshing operations cast doubt on the performance assessment of such massive plain concrete structures given the primary output assessed for these analyses should be the crack propagation and opening on the dam body....
Evaluation of Motion Selection and Scaling for the Nonlinear Seismic Analysis of Concrete Gravity Dams Soysal, Berat Feyza; Ay, Bekir Özer; Arıcı, Yalın (null; 2017-10-13) The selection and scaling of the ground motions is usually the most effective factor determining the results of the safety assessment for concrete gravity dams. The guidelines for the nonlinear transient analyses of buildings, such as the one presented in ASCE/SEI-7-10, are generally applied to these structures. While these procedures are well-studied for the moment frames, their effectiveness and consistency has not been studied for gravity dam structures. The selection and scaling of the ground motions fo...
Effect of specimen size, fiber type and concrete strength on the flexural performance of fiber reinforced concrete Güzelce, Aydinç; Yaman, İsmail Özgür; Department of Civil Engineering (2019) To overcome the brittleness of concrete, fiber reinforcement is a commonly used material, which highly increases the toughness of concrete in a cost-effective way. The aim of this study is to assess the effect of different fiber parameters on the flexural behavior of fiber reinforced concrete. Bending tests were performed on two different beam sizes made of 20 different concrete batches. The type and amount of the fibers along with the grade of the concrete were changed to form this batch combination. The f...

Citation Formats

U. Albostan, “Experimental and numerical investigation of shrinkage mechanism of plain and reinforced concrete members,” Ph.D. - Doctoral Program, Middle East Technical University, 2020.