Property analysis and mixture design of high ductility cementitious composites with totally recycled fine aggregate based on target strength and strain capacity

2022 ◽  
pp. 130492
Author(s):  
Danying Gao ◽  
Mingyan Lv ◽  
Yuyang Pang ◽  
Jiyu Tang ◽  
Yu Zhang
Keyword(s):  
Mixture Design ◽  
Target Strength ◽  
Cementitious Composites ◽  
Fine Aggregate ◽  
High Ductility ◽  
Strain Capacity ◽  
Property Analysis ◽  
Recycled Fine Aggregate

scholarly journals Experimental Study of Utilizing Recycled Fine Aggregate for the Preparation of High Ductility Cementitious Composites

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 679
Author(s):  
Dan Ying Gao ◽  
Mingyan Lv ◽  
Lin Yang ◽  
Jiyu Tang ◽  
Gang Chen ◽  
...  
Keyword(s):  
Prediction Models ◽  
Volume Fraction ◽  
Fine Aggregate ◽  
Peak Strain ◽  
High Ductility ◽  
Test Results ◽  
Cementitious Composite ◽  
Fiber Volume ◽  
Recycled Fine Aggregate ◽  
Good Agreement

Waste concrete was recycled and crushed into fine aggregate to prepare a high ductility cementitious composite (HDCC) in this study, for helping dispose the massive amount of construction waste and for reserving natural resources. Firstly, the features of recycled fine aggregate (RFA) were analyzed in detail and compared with natural fine aggregate (NFA). After that, the mechanical properties, including compression, flexure, bending and tension, and the microstructure of high ductility cementitious composite (HDCC) prepared with RFA were systematically investigated and compared with that of HDCC prepared with NFA. The results show that, since RFA has a higher water absorption rate and contains 4.86 times as much crush dust as NFA, HDCC with RFA forms a denser matrix and a higher bond between fiber and matrix than HDCC with NFA. Thus, HDCC with RFA has higher compressive, flexural, bending and tensile strength. Meanwhile, the higher bond between the fiber and matrix of HDCC with RFA and the finer particle sizes of RFA can greatly promote the development of multiple cracking. As a result, HDCC with RFA exhibits more remarkable stain hardening, and presents 182.73% higher peak deflection in bending and 183.33% higher peak strain in tension than HDCC with NFA. Finally, with the consideration of fiber volume fraction, the prediction models for the peak strengths of HDCC with RFA were proposed. The prediction results show a good agreement with the test results.

scholarly journals Engineering of composite materials made of epoxy resins modified with recycled fine aggregate

2021 ◽  
Vol 28 (1) ◽  
pp. 276-284
Author(s):  
Kamil Krzywiński ◽  
Łukasz Sadowski ◽  
Magdalena Piechówka-Mielnik
Keyword(s):  
Compressive Strength ◽  
Epoxy Resin ◽  
Cementitious Materials ◽  
Strength Test ◽  
Recycled Aggregate ◽  
Cementitious Composites ◽  
Fine Aggregate ◽  
Recycled Fine Aggregate ◽  
Resin Coating ◽  
Epoxy Resin Coating

Abstract The paper presents studies performed on polymer-cementitious composite made of epoxy resin coating modified with aggregate and cementitious substrate. Epoxy resin is a perfect material that can be used to protect cementitious materials. According to its manufacturer, it can be mixed with fine aggregate. Coarse aggregate made of building demolition wastes is mostly utilized in concrete mixtures or road structures. Fine aggregate is not widely used. Therefore, the novelty of this research was the utilization of recycled fine aggregate (RFA) in epoxy resin coatings. Natural fine aggregate (NFA) was also used as an extender in the coating. The natural aggregate in the coating was partially replaced with recycled aggregate in amounts of 0, 20, 40, 60, 80, and 100% of its weight. Sixteen specimens of polymer-cementitious composites were prepared for the flexural tensile strength test, and thirty-two specimens for the compressive strength test. The macroscale tests were performed after 35 days of curing (28 days – cementitious substrate, and 7 days – epoxy resin). The results show that the epoxy resin coating does not affect the flexural tensile and compressive strength of the analyzed composites. Moreover, the type of aggregate used in the coating does not have a significant impact on the measured properties of polymer-cementitious composites. Economic analysis was performed in order to estimate the cost of the natural and RFAs used in epoxy resin coatings. The calculations show that a higher amount of RFA should be used to increase savings.

Research on Properties of Recycled Fine Aggregate from Waste Recycled Aggregates Concrete

2011 ◽  
Vol 396-398 ◽  
pp. 93-95 ◽  
Author(s):  
Ping Hua Zhu ◽  
Xin Jie Wang ◽  
Jin Cai Feng
Keyword(s):  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Target Strength ◽  
Fine Aggregate ◽  
Structural Concrete ◽  
Recycled Fine Aggregate ◽  
Concrete Mixtures ◽  
Fine Aggregates ◽  
Mineral Compositions

The properties of recycled fine aggregate(RFA) from waste recycled aggregate concrete (RAC) were determined. In this study, five series of parental concrete mixtures using natural coarse and fine aggregates were prepared, which had the same target slump value from 35mm to 50mm and different compressive strengths ranging from 25MPa to 60 MPa. These concretes were used as recycled aggregates to prepare RACs with a compressive target strength of 30MPa. After that, these RACs were used as secondly recycled aggregates to produce RACs with the same compressive target strength of 30MPa. The physical properties of RFAs including apparent density, compacted bulk density and water absorption were tested. At the same time, fineness modulus of natural fine aggregates and RAFs were calculated and their mineral compositions were analyzed. The results showed that RAFs from waste RACs were not adequate to structural concrete alone because they belonged to coarse tape and their mineral compositions were adverse to the best growth of strength of RACs.

scholarly journals Effect of Fiber Content on the Mechanical Properties of Engineered Cementitious Composites with Recycled Fine Aggregate from Clay Brick

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3272
Author(s):  
Zhanqi Cheng ◽  
Wenhao Yan ◽  
Zhibo Sui ◽  
Jiyu Tang ◽  
Chengfang Yuan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Size Effect ◽  
Quartz Sand ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Cementitious Composites ◽  
Fine Aggregate ◽  
Fiber Volume ◽  
Engineered Cementitious Composites ◽  
Recycled Fine Aggregate

In this study, recycled fine aggregate (RFA), also known as recycled brick micro-powder (RBM), was used to completely replace quartz sand for the preparation of green, low-cost ecological engineered cementitious composites (ECO-ECC). RFA was used to replace ultrafine silica sand in the range of 0–100%. Firstly, the optimal replacement rate of RFA was determined, and the test results showed that the ECO-ECC prepared by fully replacing quartz sand with RFA as fine aggregate had strain hardening and multiple cracks, and the tensile strain of the specimens could reach 3%. Then the effects of fiber volume fraction and size effect on the mechanical properties of ECO-ECC were systematically investigated. The results showed that the fiber volume fraction has some influence on the mechanical properties of ECO-ECC. With the increase of fiber volume fraction, the ultimate deflection of the material keeps increasing up to 44.87 mm and the ultimate strain up to 3.46%, with good ductility and toughness. In addition, the compressive strength of the material has a good size effect, and there is a good linear relationship between different specimen sizes and standard sizes. It provides a good basis for engineering applications. Microscopic experimental results also showed that fibers play an important bridging role in the material, and the fiber pull-out and pull-break damage effects are significant.

scholarly journals Engineering and Manufacturing Technology of Green Epoxy Resin Coatings Modified with Recycled Fine Aggregates

2021 ◽  
Author(s):  
Kamil Krzywiński ◽  
Łukasz Sadowski ◽  
Damian Stefaniuk ◽  
Aleksei Obrosov ◽  
Sabine Weiß
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Construction And Demolition Waste ◽  
Fine Aggregate ◽  
Micro Computed Tomography ◽  
Demolition Waste ◽  
Replacement Ratio ◽  
Recycled Fine Aggregate ◽  
Fine Aggregates ◽  
Computed Tomography Scanning

AbstractNowadays, the recycled fine aggregate sourced from construction and demolition waste is not frequently used in manufacturing of epoxy resin coatings. Therefore, the main novelty of the article is to prepare green epoxy resin coatings modified with recycled fine aggregate in a replacement ratio of natural fine aggregate ranged from 20 to 100%. The microstructural properties of the aggregates and epoxy resin were analyzed using micro-computed tomography, scanning electron microscopy and nanoindentation. The macroscopic mechanical properties were examined using pull-off strength tests. The highest improvement of the mechanical properties was observed for epoxy resin coatings modified with 20% of natural fine aggregate and 80% of recycled fine aggregate. It has been found that even 100% of natural fine aggregate can be successfully replaced using the recycled fine aggregate with consequent improvement of the pull-off strength of analyzed epoxy resin coatings. In order to confirm the assumptions resulting from the conducted research, an original analytical and numerical failure model proved the superior behavior of modified coating was developed.

Influence of recycled fine aggregate on microstructure and hardened properties of concrete

2017 ◽  
Vol 69 (24) ◽  
pp. 1288-1295 ◽  
Author(s):  
Ravi Kumar ◽  
Subash Chandra Bose Gurram ◽  
Ashwani Kumar Minocha
Keyword(s):  
Fine Aggregate ◽  
Recycled Fine Aggregate ◽  
Hardened Properties
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