scholarly journals Study on Mechanical and Shrinkage Properties of High Belite Sulphoaluminate Cement-Based Green Recycled Aggregate Concrete

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1512
Author(s):  
Zexin Yu ◽  
Yuanxin Guo ◽  
Gongbing Yue ◽  
Zhenwen Hu ◽  
Chao Liu ◽  
...  
Keyword(s):  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Replacement Ratio ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Sulphoaluminate Cement ◽  
Natural Aggregate

Green recycled aggregate concrete (RAC) with high strength and low shrinkage is prepared based on recycled coarse aggregate produced by the particle-shaping and aggregate-strengthening method and green low-carbon new cement. This not only effectively alleviates the shortage of natural resources, but also improves the performance of recycled aggregate concrete, which is of great significance for multi-channel resource utilization of construction waste. In this study, three kinds of recycled coarse aggregates (RCA), including simple crushing recycled coarse aggregate (JD-RCA), one-time particle-shaping recycled coarse aggregate (KL-RCA) and two-time particle-shaping recycled coarse aggregate (EKL-RCA), were prepared from the preparation technology of recycled aggregate, and high belite sulphoaluminate cement with excellent performance was used. The effects of aggregate quality, aggregate replacement ratio, and cementitious material content on mechanical properties and shrinkage properties of green recycled aggregate concrete were studied in comparison with ordinary Portland cement-based recycled aggregate concrete. The testing results show that the particle-shaping method can effectively improve the aggregate quality. The compressive strength and dry shrinkage performance of recycled aggregate concrete made of particle-shaped aggregate are only a little different from those of natural aggregate concrete, and even the performance of recycled aggregate is better than that of natural aggregate concrete under the condition of a low replacement ratio of recycled aggregate. In addition, high belite sulphoaluminate cement-based recycled aggregate concrete (HBRAC) not only has early strength and rapid hardening, but also has excellent drying shrinkage resistance, and its shrinkage rate can be reduced to more than 75% compared with ordinary Portland cement-based recycled aggregate concrete (OPRAC).

Study on Performance of Recycled Aggregate Concrete

2011 ◽  
Vol 477 ◽  
pp. 280-289 ◽  
Author(s):  
Shao Wei Yao ◽  
Zhen Guo Gao ◽  
Chang Rui Wang
Keyword(s):  
Mechanical Properties ◽  
Coarse Aggregate ◽  
Physical And Mechanical Properties ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Chemical Solution ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Natural Aggregate ◽  
Strength And Durability

The properties of recycled coarse aggregate and the slump, the physical and mechanical properties and durability of recycled aggregate concrete were studied through tests. The results indicate that the slump, compressive strength and durability of concrete with recycled aggregate are lower than that of concrete with natural aggregate when recycled coarse aggregate fully absorbs water. However, the slump can be similar to that of concrete with natural aggregate. The properties of recycled aggregate concrete can be improved by strengthening the recycled coarse aggregate, and it is also found that the recycled coarse aggregate strengthened by grinding is superior to that soaked by chemical solution.

Experiment on Properties of Recycled Aggregate Concrete

2013 ◽  
Vol 377 ◽  
pp. 99-103 ◽  
Author(s):  
Hai Tao Yang ◽  
Shi Zhu Tian
Keyword(s):  
Mechanical Properties ◽  
Abrasion Resistance ◽  
Coarse Aggregate ◽  
Objective Measure ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Replacement Ratio ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Aggregate Content

Objective: Measure and study the mechanical properties and abrasion resistance of recycled aggregate concrete in order to provide experimental basis for the application of recycled aggregate concrete in engineering. Method: Use recycled aggregate concrete with replacement ratio of recycled coarse aggregate respectively for 0%, 30%, 50%, 80% and 100% to do the slump, compressive strength, modulus of elasticity and abrasion resistance tests on them. Result: The workability of concrete decreases with the increase of recycled coarse aggregate content. Mechanical properties of concrete change as the replacement ratios of recycled coarse aggregate change. Conclusion: The recycled aggregate concrete and natural aggregate concrete have similar abrasion resistance. The recycled aggregate concrete can be applied in engineering.

Fracture Properties and Microstructure of Concrete Made with Recycled Aggregate

2013 ◽  
Vol 773 ◽  
pp. 693-699
Author(s):  
Bing Qi ◽  
Jian Ming Gao
Keyword(s):  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Fracture Properties ◽  
Three Point Bending ◽  
Recycled Coarse Aggregate ◽  
Natural Aggregate ◽  
Beam Method

This paper presents the results of the fracture properties and microstructure of recycled aggregate concrete (RAC) compared with those of natural aggregate concrete (NAC). Concrete specimens were fabricated and tested with the recycled coarse aggregate (RCA) replacing of 0%, 40%, 70% and 100%, respectively. The three-point bending beam method was used to measure the fracture properties of the concrete. SEM and X-CT were used to investigate the microstructure of the concrete. The RCA addition in the concrete caused a decrease in the fracture properties and loose microstructure.

Eccentric compressive behavior of recycled aggregate concrete columns after freezing and thawing cycles

2018 ◽  
Vol 21 (15) ◽  
pp. 2299-2310 ◽  
Author(s):  
Jiachuan Yan ◽  
Kaihua Liu ◽  
Chaoying Zou ◽  
Jian Wang
Keyword(s):  
Coarse Aggregate ◽  
Concrete Columns ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Compressive Behavior ◽  
Freezing And Thawing ◽  
Replacement Ratio ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Freezing And Thawing Cycles

The eccentric compressive behavior of 18 recycled aggregate concrete columns after freezing and thawing cycles were investigated. The effect of the number of freezing and thawing cycles, the replacement ratio of recycled coarse aggregate, and the eccentricity of axial loading on the eccentric compressive behavior of columns was analyzed. The results show that the strain distribution along the depth of cross section of columns was plane during the eccentric compression test after freezing and thawing cycles. With the increase in the freezing and thawing cycles and the replacement ratio of recycled coarse aggregate, the failure modes of partial specimens turned from ductile tension failure to brittle compression failure. Two existing design methods for calculating the bearing capacity of conventional concrete columns subjected to eccentric compressive loading were verified to be effective for evaluating that of recycled aggregate concrete columns after limited freezing and thawing cycles.

Experimental Research on Behavior of Axially Square CFRP Steel Tubular Confined Recycled Aggregate Concrete Long Columns

2015 ◽  
Vol 744-746 ◽  
pp. 93-95
Author(s):  
Jiong Feng Liang ◽  
Ping Hua Yi ◽  
Jian Bao Wang
Keyword(s):  
Bearing Capacity ◽  
Coarse Aggregate ◽  
Slenderness Ratio ◽  
Ultimate Bearing Capacity ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Test Results ◽  
Replacement Ratio ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate

Seven axially square CFRP steel tubular confined recycled aggregate concrete long columns were experimentally investigated to study their static behavior. The influence of the slenderness ratio, recycled coarse aggregate replacement ratio, layers of CFRP jackets effect on the performance of axial compression. The test results show that the higher the recycled coarse aggregate content and the slenderness ratio, the greater the specimen ultimate bearing capacity is smaller, and the more the layers of CFRP jackets, the greater the specimen ultimate bearing capacity.

Performance of recycled aggregate concrete–filled square steel tubular columns exposed to fire

2016 ◽  
Vol 20 (9) ◽  
pp. 1340-1356 ◽  
Author(s):  
You-Fu Yang ◽  
Lei Zhang ◽  
Xianghe Dai
Keyword(s):  
Protective Coating ◽  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Analysis Model ◽  
Replacement Ratio ◽  
Element Analysis ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Tubular Columns

Experimental and theoretical investigation on the fire performance of concentrically loaded recycled aggregate concrete–filled square steel tubular columns with or without fire protective coating is reported in this article. Tests of nine specimens were conducted with the variation in the recycled coarse aggregate replacement ratio, axial compressive load ratio and thickness of fire protective coating. The failure pattern, typical temperature development, axial displacement and fire resistance of the tested specimens are presented and analysed. The experimental results reveal that the temperatures of the core concrete decrease with increasing recycled coarse aggregate replacement ratio and decreasing thickness of fire protective coating under the same fire exposure time. In general, the specimens with the recycled coarse aggregate replacement ratio of 50% have a similar behaviour as the corresponding specimen with normal concrete; however, the performance of specimens with the recycled coarse aggregate replacement ratio of 100% is clearly different from the reference specimen with normal concrete. Moreover, the fire resistance of recycled aggregate concrete–filled square steel tubular columns increases with an increase in the thickness of fire protective coating and a decrease in axial compressive load ratio. A finite element analysis model was developed for simulating the performance of recycled aggregate concrete–filled square steel tubular columns exposed to fire, and the finite element analysis model was validated against the experimental results.

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.

scholarly journals Properties of Concrete Using Treated Low-Class Recycled Coarse Aggregate and Blast Furnace Slag Sand

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 843
Author(s):  
Yuji Miyazaki ◽  
Takeshi Watanabe ◽  
Yuji Yamada ◽  
Chikanori Hashimoto
Keyword(s):  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Coarse Aggregate ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Hardened Concrete ◽  
Freezing And Thawing ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Furnace Slag

Since high quality natural aggregates are becoming scarce, it is important that industrial recycled products and by-products are used as aggregates for concrete. In Japan, the use of recycled aggregate (RG) is encouraged. Since, strength and durability of recycled aggregate concrete is lower than that of normal aggregate concrete, the use of recycled aggregate has not been significant. In order to improve physical properties of concrete using recycled coarse aggregate, blast furnace slag sand has been proposed. Recently, blast furnace slag sand is expected to improve durability, freezing, and thawing damage of concrete in Japan. Properties of fresh and hardened concrete bleeding, compressive strength, and resistance to freezing and thawing which are caused by the rapid freezing and thawing test using liquid nitrogen is a high loader than the JIS A 1148 A method that were investigated. As a result, concrete using treated low-class recycled coarse aggregate and 50% or 30% replacement of crushed sand with blast furnace slag sand showed the best results, in terms of bleeding, resistance to freezing and thawing.

Comparative study of tensile tests based on Hopkinson bar for recycled aggregate concrete

2018 ◽  
Vol 10 (1) ◽  
pp. 26-53
Author(s):  
Junzhou Duan ◽  
Yubin Lu ◽  
Shu Zhang ◽  
Xiquan Jiang
Keyword(s):  
Tensile Strength ◽  
Strain Rate ◽  
Coarse Aggregate ◽  
Tensile Tests ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Dynamic Tensile Strength ◽  
Aggregate Concrete ◽  
Recycled Coarse Aggregate ◽  
Direct Tensile

To comparatively study the tensile properties and fracture patterns of recycled aggregate concrete with various replacement percentages (i.e. 0%, 25%, 50%, 75%, and 100%) of recycled coarse aggregate, the dynamic direct tensile tests, splitting tests, and spalling tests of recycled aggregate concrete in the strain-rate range of 100–102 s−1 were carried out using large diameter (75 mm) split Hopkinson tensile bar and pressure bar. Test results show that for recycled aggregate concrete, the quasi-static direct tensile strength is more marvelous than its quasi-static splitting strength. When recycled coarse aggregate replacement percentage is 0%–75%, the replacement percentage impact minimally on the quasi-static tensile strength of recycled aggregate concrete. In dynamic tensile tests, there exists apparent difference between the dynamic direct tensile strength and dynamic splitting. The dynamic tensile strength of recycled aggregate concrete increases with the increase of average strain-rate in all three kinds of tests. The average strain-rate affects the damage form of recycled aggregate concrete, which indicates that the recycled aggregate concrete has obvious rate sensitivity. There shows no obvious regularity between the dynamic tensile strength and the recycled coarse aggregate replacement percentage. And the indirect tensile strength calculation method used in this article offers the theoretical basis for the engineering application of recycled aggregate concrete.

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