Study on Affection of the PVA Fiber on Recycled Coarse Aggregate to Porous Concrete Performance

2013 ◽  
Vol 438-439 ◽  
pp. 304-308 ◽  
Author(s):  
Du La Man

Pervious concrete is one kind of porous concrete which has skeleton structure. In this test the recycled coarse aggregate replacement ratio is 30%, by using recycled coarse aggregate which through high quality processing replaces ordinary coarse aggregate and adding PVA fiber (the mass of PVA fiber respectively are 0%, 0.5%, 1.0% and 1.5% of the cement), the influences of PVA fiber on the strength, effective porosity and permeable coefficient of porous concrete are studied. Besides, the dry shrinkage property and temperature contraction property of porous concrete are discussed. The results can provide the basis for the design and application of the recycled coarse aggregate porous concrete.

2021 ◽  
Vol 13 (23) ◽  
pp. 13200
Author(s):  
Yang Yu ◽  
Peihan Wang ◽  
Zexin Yu ◽  
Gongbing Yue ◽  
Liang Wang ◽  
...  

Shrinkage property is a significant indicator of the durability of concrete, and the shrinkage of green recycled concrete is particularly problematic. In this paper, construction waste was crushed and screened to generate simple-crushed recycled coarse aggregate (SCRCA). The SCRCA was then subjected to particle shaping to create primary particle-shaped recycled coarse aggregate (PPRCA). On this basis, the PPRCA was particle-shaped again to obtain the secondary particle-shaped recycled coarse aggregate (SPRCA). Under conditions where the dosage of cementitious material is 300 kg/m3 and the sand rate is 38%, a new high-belite sulphoaluminate cement (HBSAC) with low carbon emission and superior efficiency was used as the basic cementitious material. Taking the quality of recycled coarse aggregate (SCRCA, PPRCA, and SPRCA) and the replacement ratio (25%, 50%, 75%, and 100%) as the influencing factors to prepare the green recycled concrete, the workability and shrinkage property of the prepared concrete were analyzed. The results show that the water consumption of green recycled concrete decreases as the quality of the recycled coarse aggregate (RCA) increases and the replacement ratio decreases, provided that the green recycled concrete achieves the same workability. With the improvement of RCA quality and the decrease of replacement ratio, the shrinkage of recycled concrete decreases. The shrinkage performance of green recycled concrete configured with the SPRCA completely replacing the natural coarse aggregate (NCA) is basically the same as that of the natural aggregate concrete (NAC).


2011 ◽  
Vol 147 ◽  
pp. 288-292 ◽  
Author(s):  
Yong Taeg Lee ◽  
Seong Uk Hong ◽  
Hyun Suk Jang ◽  
Sang Ki Baek ◽  
Young Sang Cho

National effort to recycle construction waste as structural concrete usage of high economic value is ongoing, but performance rate of recycling is a low-level due to a lack of awareness on the recycled aggregates. Accordingly, the goal of this study was to verify the structural applicability of recycled aggregates. This study compared a compressive strength based on the replacement ratio of natural aggregate and recycled aggregate, and analyzed a correlation of wave velocity due to the increase in compressive strength under the same condition. The 『design standard strength – replacement ratio of recycled coarse aggregate』 was set to total 12 combinations by applying 0, 30, 50, 100[%] replacement ratio of recycled coarse aggregate to 21, 27, 35[MPa] to the design standard strength. During the experiment of fracture strength, strength degradation due to the replacement rate of recycled coarse aggregate did not occur, and it was found that the wave velocity also increased along with an increase in strength due to the age of recycled coarse aggregate concrete.


2013 ◽  
Vol 377 ◽  
pp. 99-103 ◽  
Author(s):  
Hai Tao Yang ◽  
Shi Zhu Tian

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.


2012 ◽  
Vol 598 ◽  
pp. 635-639
Author(s):  
Zhao Hua Du ◽  
Jie Wang

In this paper, the mixture ratio of recycled concrete and its fundamental mechanics properties have been researched by experiments, which include the mechanical properties of recycled aggregate, the optimum mix design of the recycled concrete, compressive strength tests on concrete specimens using the broken abandoned concrete rubbles as recycled coarse aggregate, the replacement ratios of recycled coarse aggregate by mass to the natural coarse aggregate are 0, 0.3, 0.5, 0.70 and 1.0 respectively. The influences of the replacement ratio of recycled coarse aggregate by mass to the fundamental properties of the recycled concrete such as the compressive strength,and the elastic modulus are discussed and analyzed.and the optimum replacement ratio of recycled coarse aggregate by mass is suggested. These may be references to the applications of recycled concrete in engineering.


2018 ◽  
Vol 21 (15) ◽  
pp. 2299-2310 ◽  
Author(s):  
Jiachuan Yan ◽  
Kaihua Liu ◽  
Chaoying Zou ◽  
Jian Wang

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.


2015 ◽  
Vol 744-746 ◽  
pp. 93-95
Author(s):  
Jiong Feng Liang ◽  
Ping Hua Yi ◽  
Jian Bao Wang

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.


2011 ◽  
Vol 261-263 ◽  
pp. 75-78 ◽  
Author(s):  
Yi Li ◽  
Jun Lin Tao ◽  
Ting Lei ◽  
Jian Jun Xie

Recycled concrete which are made by waste concrete has significance of environmental protection and saving natural resources. But there are different study results of recycled concrete of domestic and foreign scholars, so it is necessary to do the further study of recycled concrete. Compressive strength test of 225 concrete standard cube specimens have been done by Hydraulic Type Universal Testing Machine, and the relationships among recycled concrete compressive strength, age and recycled coarse aggregate replacement ratio have been studied. The results show: the growth rate of early strength of recycled concrete is smaller than natural concrete of the same gradation and the growth rate of later strength of recycled concrete is faster than natural concrete; when the recycled coarse aggregate replacement ratio increases the compressive strength of concrete decreases, and when the recycled coarse aggregate replacement ratio is over 70%, the decrease ranges more apparent.


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