Experimental Research on Behavior of Composite Beams of Steel-Reinforced Recycled Concrete

2013 ◽  
Vol 639-640 ◽  
pp. 145-148 ◽  
Author(s):  
Yan Dong Jia ◽  
Ying Kai Guo ◽  
Zhi Ping Sun ◽  
Xin Zhao
Keyword(s):  
Composite Structures ◽  
Coarse Aggregate ◽  
Concrete Beams ◽  
Failure Process ◽  
Limit Load ◽  
Maximum Load ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Cement Slurry ◽  
Recycled Coarse Aggregate

The recycled aggregate is dealt with in three ways, the first way is to keep the recycled aggregate intact; the second way is to wrap the recycled aggregate in cement slurry of Water-cement ratio 0.55 for 30 minutes, and then place it at room temperature for 7 days; the third way is to immerse the recycled aggregate in water for 24 hours. Three kinds of different recycled aggregate is separately used for mixing of recycled concrete. The strength and slump of recycled concrete with different recycled coarse aggregate contents are tested. Experiments show that the recycled concrete produced by using the recycled aggregate immersed in water and selecting a suitable mix has the higher strength and slump，which can be industrialized. And then, the recycled concrete with 40% recycled coarse aggregate contents is used in the steel-reinforced recycled concrete beams, which are tested, the failure process of steel-reinforced recycled concrete beams,section strains and maximum load are acquired. Research shows the steel-reinforced recycled concrete beams conform to plane hypothesis before the load reachs 80% the limit load, the flexural bearing capacity of the steel-reinforced recycled concrete beams can meet the demand of Technichal Specification of Steel-Reinforced Concrete Structures. The use of recycled concrete in the composite structures is proposed.

The High Quality Technical Research of Road Concrete Recycled Coarse Aggregate

2011 ◽  
Vol 346 ◽  
pp. 47-51 ◽  
Author(s):  
M. Mandula ◽  
Xiao Yu Hu ◽  
Feng Jin Chen ◽  
Wen Long Zhang
Keyword(s):  
Coarse Aggregate ◽  
Chemical Characteristic ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Cement Slurry ◽  
High Quality ◽  
Ordinary Concrete ◽  
Recycled Coarse Aggregate ◽  
Waste Concrete ◽  
Physical And Chemical

This paper studies the recycling of solid waste concrete of the foundational content. Through the experimental research on the use of recycled aggregate and recycled concrete powder, I propose recycled coarse aggregate, recycled powder of various physical and chemical characteristic and the powder mixed with cement slurry mixed with recycled coarse aggregate on the surface of the mechanical properties after treatment. The results show that the coarse aggregate crushing value after surface treatment, strength characteristics of concrete can meet the requirements of ordinary concrete.

Experimental Study on Flexural Behaviors of Steel Reinforced Recycled Coarse Aggregate Concrete Beams

2012 ◽  
Vol 166-169 ◽  
pp. 1614-1619 ◽  
Author(s):  
Wen Yue Qin ◽  
Yu Liang Chen ◽  
Zong Ping Chen
Keyword(s):  
Bearing Capacity ◽  
Coarse Aggregate ◽  
Concrete Beams ◽  
Concrete Strength ◽  
Recycled Concrete ◽  
Flexural Behavior ◽  
Aggregate Concrete ◽  
Strength Grade ◽  
Recycled Coarse Aggregate ◽  
The Impact

In order to reveal the flexural behavior of normal section of steel reinforced recycled coarse aggregate concrete beams，6 steel reinforced recycled concrete beams were designed for flexural test，the study mainly considered the impact of coarse aggregate replacement rates and concrete strength grade two changing parameters on the flexural behavior of steel reinforced recycled coarse aggregate concrete beams. Through this test, the whole mechanical process、crack distribution and failure behavior of this kind of specimens were observed, and obtained the stress-strain distribution curves、the ultimate bearing capacity and load-displacement curves parameters. Based on the study measurement data, deeply analyzed the impact of coarse aggregate replacement rates and concrete strength grade on the flexural behavior of steel reinforced recycled coarse aggregate concrete beams. The result shows that: steel reinforced recycled coarse aggregate concrete beams’ failure pattern was similar to normal SRC beams, during loading process the section strain agreed with the plane-section assumption, and the beams have good bearing capacity and deformation performance.

Experimental Research on Mechanical Properties of Recycled Aggregate Concrete under Uniaxial Loading

2013 ◽  
Vol 671-674 ◽  
pp. 1736-1740
Author(s):  
Xue Yong Zhao ◽  
Mei Ling Duan
Keyword(s):  
Elastic Modulus ◽  
Coarse Aggregate ◽  
Strain Curve ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Peak Strain ◽  
Stress Strain ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate

The complete stress-strain curves of recycled aggregate concrete with different recycled coarse aggregate replacement percentages were tested and investigated. An analysis was made of the influence of varying recycled coarse aggregate contents on the complete stress-strain curve, peak stress, peak strain and elastic modulus etc. The elastic modulus of RC is lower than natural concrete (NC), and with the recycled coarse aggregate contents increase, it reduces. While with the increase of water-cement ratio (W/C), recycled concrete compressive strength and elastic modulus improve significantly. In addition, put forward a new equation on the relationship between Ec and fcu of the RC.

Experimental Research on Main Properties of New Recycled Coarse Aggregate Concrete

2011 ◽  
Vol 261-263 ◽  
pp. 19-23 ◽  
Author(s):  
Da Xing Qian ◽  
Ying Wei Yun ◽  
Ii Young Jang ◽  
Jong Hoe Kim
Keyword(s):  
Concrete Beam ◽  
Coarse Aggregate ◽  
Economic Benefits ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Secondary Process ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Waste Concrete

Recently reutilization of waste concrete becomes one of the hottest issues in civil engineering field throughout the world. However, most of the concerned research focuses on the RCA (recycled coarse aggregate) by simply crushing waste concrete. In this paper shucking technique is developed to secondary process the simply crushing waste concrete for improving the performance of RCA concrete. Test has been done to demonstrate that performances such as strength, elastic modulus et al. of shucking RCA concrete is better than those of common recycled concrete. Simultaneously, beam specimens are made to test the flexural behavior of shucking RCA concrete. Results showed that the deflection of shucking RCA concrete beam is approximately same with that of natural coarse aggregate concrete beam, which solves current problem that recycled aggregate concrete beam has bigger deflection than common concrete beam. The new shucking technique developed in this paper has many advantages to be applied in practical engineering and it has obvious economic benefits and social effect.

scholarly journals Fractal characteristic of recycled aggregate and its influence on physical property of recycled aggregate concrete

2021 ◽  
Vol 60 (1) ◽  
pp. 663-677
Author(s):  
Song Gao ◽  
Qiuyi Li ◽  
Jianlin Luo
Keyword(s):  
Fractal Dimension ◽  
Coarse Aggregate ◽  
Physical Property ◽  
Fractal Dimensions ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Boundary Line ◽  
Type I ◽  
Recycled Coarse Aggregate

Abstract Fractal dimension is introduced to describe the complicated characteristics of recycled aggregate and their influence on properties of recycled concrete as an integrated indicator. The fractal dimensions of both particle outline and distribution of recycled aggregate have obvious self-similarity and fractal characteristics. The order of the bulk density, water absorption, and crushing index of recycled aggregate in particle group state is clearly and directly related to the fractal dimension of boundary line. Additionally, the fractal dimension of the distribution of recycled coarse aggregate in concrete decreases in order of natural aggregate, Type I, Type II, and Type III recycled coarse aggregate; smaller distribution dimension value represents more concentrated distribution of aggregate, and 7 and 28 days compressive strength of the corresponding recycled concrete increases. The fractal dimension method is an effective process to assess comprehensive performances of recycled aggregate and helpful to establish a quantitative evaluation criterion for its wide applications.

Properties of the Recycled Aggregate Concrete

2012 ◽  
Vol 217-219 ◽  
pp. 866-868
Author(s):  
Wei Ren
Keyword(s):  
Coarse Aggregate ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Performance Impact ◽  
Construction Waste ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Concrete Blocks

This paper studies the construction waste recycled coarse aggregate concrete blocks including waste and brick, through the control of brick in the admixture of recycled coarse aggregate concrete, compound to regenerate waste away in the analysis and research of the brick dosage of recycled concrete performance impact.

Microscopic Mechanism Study on Carbonation Resistance of Recycled Aggregate Concrete

2011 ◽  
Vol 194-196 ◽  
pp. 1001-1006 ◽  
Author(s):  
Hai Feng Yang ◽  
Zhi Heng Deng ◽  
Xue Liang Li
Keyword(s):  
Fly Ash ◽  
Coarse Aggregate ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Replacement Rate ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Concrete Carbonation ◽  
Carbonation Resistance

24 100mm × 100mm × 300mm recycled concrete prisms and 96 150mm × 150mm × 150mm cubes are completed in this paper.The relationships of the carbonation depth in each carbonation age with replacement rate of recycled coarse aggregate and fly ash is studied; The SEM is used to observe the interface structure of recycled coarse aggregate concrete and compared with ordinary concrete, and finally,a recycled concrete carbonation model is proposed. The results showed that: the substitution of recycled coarse aggregate and fly ash cut down the recycled concrete carbonation resistance significantly, which are related with the replacement rate; the content of Ca(OH)2 in the recycled aggregate concrete decreased ,also there are obvious interface transition zone between the recycled coarse aggregate and the new cement;obvious cracks and large voids are exist before the recycled aggregate concrete is loaded, which lead directly to lower carbonation resistance of the recycled concrete.

scholarly journals The influence of recycled concrete aggregate on the properties of concrete

2018 ◽  
Vol 162 ◽  
pp. 02020 ◽  
Author(s):  
Nisreen Mohammed ◽  
Kaiss Sarsam ◽  
Mazin Hussien
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Modulus Of Rupture ◽  
Concrete Aggregate ◽  
Hardened Concrete ◽  
Recycled Coarse Aggregate ◽  
Natural Aggregates

Use of Recycled Coarse Aggregate (RCA) in concrete can be described in terms of environmental protection and economy. This paper deals with the mechanical properties of concrete compressive strength, splitting tensile strength, modulus of elasticity, and modulus of rupture. Three kinds of concrete mixtures were tested, concrete made with Natural Coarse Aggregate (NCA) as a control concrete and two types of concrete made with recycled coarse aggregate (50% and 100% replacement level of coarse recycled aggregate). These kinds of concrete were made with different targets of compressive strength of concrete f ’c (35MPa) and (70 MPa). Fifty specimens were tested of the fresh and hardened properties of concrete. The waste concrete from laboratory test cubes was crushed to produce the Recycled Coarse Aggregate used in recycled concrete. A comparative between the experimental results of the properties for fresh and hardened concrete is presented in the paper. Recycled aggregate concrete (RCA) had a satisfactory performance despite the replacement ratios. It was found using the size of Recycled Coarse Aggregate (RCA) of (5-14) mm has quite similar in performance with the same size of Natural Coarse Aggregate (NCA), it is necessary to use high quality of recycled concrete (with low levels of impurities). Recycled aggregate as an alternative to natural aggregates -seems quite successful.

Study on Properties of Self-Compacting Concrete Prepared with Coarse Recycled Concrete Aggregate

2014 ◽  
Vol 638-640 ◽  
pp. 1494-1498 ◽  
Author(s):  
Jian Jie Yu ◽  
Jian Gong ◽  
Jie Ming Zou ◽  
Wei Kang Yang
Keyword(s):  
Coarse Aggregate ◽  
Recycled Concrete ◽  
Working Environment ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Self Compacting Concrete ◽  
Recycled Coarse Aggregate ◽  
Concrete Mixtures ◽  
Crushed Concrete ◽  
Construction Efficiency

Self-compacting concrete is absent of vibration noise during casting, improves the construction efficiency, and provides a healthier working environment compared to the traditional vibrated concrete. The potential coarse recycled aggregate obtained from crushed concrete for making self-compacting concrete was considered to replace the aggregate with the percentage of substitution of recycled coarse aggregate 0%, 50% and 100%. Thus, three types of concrete mixtures were made. Experiments show that, the properties of these concrete only have slight differences and recycled coarse aggregate can be successfully used for the preparation of self-compacting concrete. The method solves the problem of the waste disposal by the demolition of old buildings.

Structural Responses of Recycled Concrete Beams under Room Temperature

2014 ◽  
Vol 711 ◽  
pp. 448-453
Author(s):  
Wen Xiao Cui ◽  
Zhong Fan Chen
Keyword(s):  
Room Temperature ◽  
Coarse Aggregate ◽  
Concrete Beams ◽  
Recycled Concrete ◽  
Bearing Strength ◽  
Recycled Coarse Aggregate ◽  
Structural Responses ◽  
Strength And Deformation ◽  
Bending Failure ◽  
Flat Section

Three full-scale reinforced supported beams with different recycled coarse aggregate percentage were researched and compared in order to research their structural responses under different temperature. This paper investigated the impacts of recycled coarse aggregate on the strain of concrete, deformation and the bearing strength of specimen. The experiments show that the flat section assumption is available for RAC components. Besides, the failure force of RAC components is slightly poorer than that of NAC component. By analyzing a large number of studies, the predictions of bending failure strength and deformation of RAC specimen according to the code for design concrete structures (CDCS) are compared with the experimental results. Besides, the bending performances under room temperature and fire were compared.

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