Assessing the Fracture and Damage Process in Recycled Aggregate Concrete under Compressive Loading by Acoustic Emission

2010 ◽  
Vol 163-167 ◽  
pp. 2528-2531
Author(s):  
Seung Hyun Ryu ◽  
Young Oh Lee ◽  
Sun Woo Kim ◽  
Hyun Do Yun
Keyword(s):  
Acoustic Emission ◽  
Nondestructive Test ◽  
Crack Growth ◽  
Compressive Loading ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Damage Process ◽  
Degree Of Damage ◽  
Ae Signals

Acoustic emission (AE) is a powerful nondestructive test that can be used to characterize cracking, growth of cracks, and the degree of damage. This technique is clearly distinguished from other nondestructive techniques as it is a nondestructive test that estimates the degree of damage to concrete. In this study, the AE signals emitted during failure, according to the strength of recycled aggregate concrete specimens was examined, in order to characterize them using existing research results and evaluation theories. In addition, it is demonstrated that AE can be utilized to identify crack source and the mechanism of crack growth, which were monitored using a software program developed from the theory of the location of the source of a microcrack.

scholarly journals On the Structural Performance of Recycled Aggregate Concrete Columns with Glass Fiber-Reinforced Composite Bars and Hoops

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1508
Author(s):  
Ali Raza ◽  
Ahmad Rashedi ◽  
Umer Rafique ◽  
Nazia Hossain ◽  
Banjo Akinyemi ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Compressive Loading ◽  
Reinforcement Ratio ◽  
Recycled Aggregate Concrete ◽  
Experimental Results ◽  
Recycled Aggregate ◽  
Fiber Reinforced ◽  
Aggregate Concrete ◽  
Gfrp Bars ◽  
Glass Fiber Reinforced

Structural members comprising geopolymer recycled aggregate concrete (RAC) reinforced with glass fiber-reinforced polymer (GFRP) bars have not been investigated appropriately for axial compressive loading cases. The present study addresses this knowledge gap by evaluating the structural efficiency of GFRP-reinforced geopolymer recycled aggregate concrete (GGRAC)-based members subjected to axial compressive loading. A total of nine compressive members (250 mm in cross-section and 1150 mm in height) were constructed to examine the effect of the number of longitudinal GFRP bars and the vertical spacing of transverse GFRP hoops/ties. The experimental results portrayed that the ductility of GGRAC compressive members improved with the reduction in the pitch of GFRP hoops. The axial load-carrying capacity (LCC) of GGRAC compressive members increased by increasing the number of GFRP bars up to eight (corresponding to a reinforcement ratio of 2.11%) while it decreased by using ten longitudinal GFRP bars (corresponding to a reinforcement ratio of 2.65%). Additionally, an empirical model was suggested to predict the axial LCC of GGRAC compressive members based on a large amount of experimental data of similar members. The experimental results and related theoretical predictions substantially prove the applicability and accuracy of the proposed model. The proposed column represents a feasible structural member in terms of material availability and environmental sustainability.

scholarly journals Dynamic Compressive Strength of Recycled Aggregate Concrete

2021 ◽  
Vol 8 ◽  
pp. 56-61
Author(s):  
Shamsoon Fareed ◽  
Asad-ur-Rehman Khan ◽  
Samra Masood
Keyword(s):  
Dynamic Properties ◽  
Compressive Loading ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Maximum Height ◽  
Environmental Preservation ◽  
Aggregate Concrete ◽  
Drop Hammer ◽  
Static Mechanical

Over the years the construction waste has enormously increased, this may be attributed to different factors such as (i) demolition (ii) accidents (iii) impact loads (iv) earthquakes. These activities have caused an increasing burden on already exhausted waste management system globally. As a result, the concrete waste produced in a large quantity has become a major issue to manage due to limited landfill sites. Therefore, the recycling of waste concrete can prove to be beneficial and necessary for the environmental preservation and effective utilization of natural resources. Number of studies have been conducted to study the static mechanical properties of recycled aggregate concrete; however, limited test data has been published which focused on the dynamic properties of the concrete prepared with recycled coarse aggregates. Therefore, in this investigation aim was to study the behavior of recycled aggregates concrete under increasing dynamic compressive loading. For this purpose, cylindrical specimens having a diameter of 100 mm and height of 200 mm were used. These specimens have been prepared with constant concrete mix ratio, having varying percentages of RA such as 0%, 30%, and 50% 70 % and 100%. The dynamic compressive behaviour was studied by using drop hammer system. The height drop hammer system consist of a frame having a maximum height of 15ft. Firstly, three samples (1, 1R, 2R) from each percentage replacement (0%, 30%, 50%, 70% and 100%) were tested on six different velocities of 2.44m/s, 3.45m/s, 4.23m/s, 4.89m/s, 5.46m/s and 7.45m/s with varying strain rates of 12.04/s, 17.00/s, 20.83/s, 24.08/s, 26.89/s and 36.73/s respectively. Weight of the drop hammer was 10 kg. Based on the detailed experimental investigation, it was found that the behaviour of the recycled aggregate concrete under dynamic loading differ significantly from the static loading.

Fracture Analysis for a 2D Prototype of Recycled Aggregate Concrete Using Discrete Cracking Model

2009 ◽  
Vol 417-418 ◽  
pp. 681-684
Author(s):  
Jian Zhuang Xiao ◽  
Yu Ching Wu ◽  
Sheng Dong Zhang
Keyword(s):  
Numerical Model ◽  
Compressive Loading ◽  
Fracture Analysis ◽  
Recycled Aggregate Concrete ◽  
Constitutive Law ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
3 Dimensional ◽  
Concrete Plate ◽  
Concrete Efficiency

Fracture analysis has been made for a 2 dimensional prototype of recycled aggregate concrete using the discrete cracking model. The discrete element method has been developed based on quasi-brittle constitutive law to simulate the behavior of the 2 dimensional recycled aggregate concrete prototype under uniaxial compressive loading. The relationship between stress distribution and failure mechanism of the recycled aggregate concrete plate has been investigated and analyzed. The numerical model proposed in the paper is in the first time used to analyze the mechanical properties of recycled aggregate concrete. Efficiency and accuracy of the numerical model has been demonstrated. It is indicated that this model has potential to be extended for 3 dimensional structural analysis of recycled aggregate concrete.

The Compressive Strength and Flexural Strength Test of Recycled Pebble Aggregate Concrete

2013 ◽  
Vol 357-360 ◽  
pp. 1433-1436
Author(s):  
Zong Ping Chen ◽  
Chun Heng Zhou ◽  
Pei Huan Ye
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Test Results ◽  
Replacement Rate ◽  
Normal Concrete ◽  
Aggregate Concrete ◽  
Damage Process

Primary concrete of pebble coarse aggregate were used as the source of recycled aggregate concrete for pebble recycled coarse aggregate. Replacement rate of recycled aggregate for change parameter, 99 specimens were designed. The prism compressive strength, cube compressive strength and flexural strength were tested and achieved. The test results show that damage process and form of pebble coarse aggregate concrete are similar to those of normal concrete. It is gel adhesive failure between coarse aggregate and cement. Comparing with natural aggregate concrete, the strength indexes of recycled aggregate concrete of pebble coarse Aggregate slightly increase.

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