scholarly journals Permeability and Leaching Properties of Recycled Concrete Aggregate as an Emerging Material in Civil Engineering

2018 ◽  
Vol 9 (1) ◽  
pp. 81 ◽  
Author(s):  
Andrzej Głuchowski ◽  
Wojciech Sas ◽  
Justyna Dzięcioł ◽  
Emil Soból ◽  
Alojzy Szymański
Keyword(s):  
Statistical Analysis ◽  
Water Solution ◽  
Recycled Concrete ◽  
Test Method ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Average Coefficient ◽  
Constant Head ◽  
Constant Head Method ◽  
Recycled Material

In this article, a study of the threshold gradient and leaching properties for recycled material, namely, recycled concrete aggregate (RCA), was conducted. The RCA in this study is a material that comes from recycling concrete debris. A series of tests in permeameter apparatus in a constant head manner were conducted. The test method has been improved to eliminate common mistakes, which occur when the constant head method is used. During the following study, aggregates with gradations equal to 0–8, 0–16, and 0.05–16 mm were tested. The tests were conducted on gradients ranging from 0.2 to 0.83. This range of tested gradients led to the evaluation of the flux velocity and indicated non-Darcian flow. For engineering applications, the threshold gradients for three RCA blends were calculated using a statistical analysis. The average coefficient of permeability, kavg, for linear flow was equal to 1.02 × 10−4–1.89 × 10−4 m/s. In this paper, suffosion analysis was also conducted for the three blends in order to eliminate the possibility of particle movement. Moreover, for RCA blend 0–16 mm, leaching properties was examined. It was found that the concentration of chlorides, sulphates, and heavy metals in the water solution does not exceed the permissible standards. This paper ends with conclusions and proposals concerning the threshold gradients obtained from the statistical analysis, suffosion analysis, and flux velocity.

scholarly journals Toward the use of high volume recycled concrete aggregate in new concrete production

2021 ◽  
Author(s):  
Anto Sucic
Keyword(s):  
High Volume ◽  
Recycled Concrete ◽  
Mix Design ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Fresh Properties ◽  
Waste Concrete ◽  
Concrete Production ◽  
Hardened Properties ◽  
Recycled Material

This thesis reports the findings of a study carried out to determine the feasibility of using Recycled Concrete Aggregate (RCA) in the production of newly made concrete at high replacement levels of conventional coarse Virgin Aggregates (VA). The study evaluated the properties of new concrete produced with coarse RCA, in order to address the issues typically associated with the characteristics of the recycled material. Concrete specimens were tested for fresh properties, hardened properties, as well as overall durability of mixes. Making minor modifications in mix design, the drawbacks typically associated with the use of RCA were successfully mitigated at high replacement levels, making up to a full 100% replacement feasible. Through the use of higher replacement levels of RCA in the production of concrete, the environmental impacts of VA harvesting may be significantly reduced, as well as providing a more economical means of waste concrete disposal for ready mix producers.

scholarly journals Toward the use of high volume recycled concrete aggregate in new concrete production

2021 ◽  
Author(s):  
Anto Sucic
Keyword(s):  
High Volume ◽  
Recycled Concrete ◽  
Mix Design ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Fresh Properties ◽  
Waste Concrete ◽  
Concrete Production ◽  
Hardened Properties ◽  
Recycled Material

This thesis reports the findings of a study carried out to determine the feasibility of using Recycled Concrete Aggregate (RCA) in the production of newly made concrete at high replacement levels of conventional coarse Virgin Aggregates (VA). The study evaluated the properties of new concrete produced with coarse RCA, in order to address the issues typically associated with the characteristics of the recycled material. Concrete specimens were tested for fresh properties, hardened properties, as well as overall durability of mixes. Making minor modifications in mix design, the drawbacks typically associated with the use of RCA were successfully mitigated at high replacement levels, making up to a full 100% replacement feasible. Through the use of higher replacement levels of RCA in the production of concrete, the environmental impacts of VA harvesting may be significantly reduced, as well as providing a more economical means of waste concrete disposal for ready mix producers.

scholarly journals Physical, Deformation, and Stiffness Properties of Recycled Concrete Aggregate

2021 ◽  
Vol 13 (8) ◽  
pp. 4245
Author(s):  
Katarzyna Gabryś ◽  
Emil Soból ◽  
Wojciech Sas
Keyword(s):  
Recycled Concrete ◽  
Experimental Program ◽  
Concrete Aggregate ◽  
Test Results ◽  
Recycled Concrete Aggregate ◽  
Granulometric Analysis ◽  
Stiffness Properties ◽  
Grain Distribution ◽  
Natural Aggregates ◽  
Critical Reduction

The construction sector is currently struggling with the reuse of waste originating from the demolition and modernization of buildings and roads. Furthermore, old buildings are gradually being replaced by new structures. This brings a significant increase of concrete debris to waste landfills. To prevent this, many studies on the possibilities of recycling concrete, known as recycled concrete aggregate (RCA), have been done. To broaden the applicability of reused concrete, an understanding of its properties and engineering behavior is required. A difficulty in sustainable, proper management of RCA is the shortage of appropriate test results necessary to assess its utility. For this reason, in the present study, the physical, deformation, and stiffness properties of RCA with gravely grain distribution were analyzed carefully in the geotechnical laboratory. To examine the mentioned properties, an extensive experimental program was planned, which included the following studies: granulometric analysis, Proctor and oedometer tests, as well as resonant column tests. The obtained research results show that RCA has lower values of deformation and stiffness parameters than natural aggregates. However, after applying in oedometer apparatus repetitive cycles of loading/unloading/reloading, some significant improvement in the values of the parameters studied was noticed, most likely due to susceptibility to static compaction. Moreover, some critical reduction in the range of linear response of RCA to dynamic loading was observed.

scholarly journals Roller Compacted Concrete with Recycled Concrete Aggregate for Paving Bases

2020 ◽  
Vol 12 (8) ◽  
pp. 3154 ◽  
Author(s):  
Hedelvan Emerson Fardin ◽  
Adriana Goulart dos Santos
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Modulus Of Elasticity ◽  
Splitting Tensile Strength ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Roller Compacted Concrete ◽  
Flexural Tensile Strength ◽  
Mechanical And Physical Properties

This research aimed to investigate the mechanical and physical properties of Roller Compacted Concrete (RCC) used with Recycled Concrete Aggregate (RCA) as a replacement for natural coarse aggregate. The maximum dry density method was adopted to prepare RCC mixtures with 200 kg/m³ of cement content and coarse natural aggregates in the concrete mixture. Four RCC mixtures were produced from different RCA incorporation ratios (0%, 5%, 15%, and 30%). The compaction test, compressive strength, splitting tensile strength, flexural tensile strength, and modulus of elasticity, porosity, density, and water absorption tests were performed to analyze the mechanical and physical properties of the mixtures. One-way Analysis of Variance (ANOVA) was used to identify the influences of RCA on RCC’s mechanical properties. As RCA increased in mixtures, some mechanical properties were observed to decrease, such as modulus of elasticity, but the same was not observed in the splitting tensile strength. All RCCs displayed compressive strength greater than 15.0 MPa at 28 days, splitting tensile strength above 1.9 MPa, flexural tensile strength above 2.9 MPa, and modulus of elasticity above 19.0 GPa. According to Brazilian standards, the RCA added to RCC could be used for base layers.

Sign in / Sign up

Export Citation Format

Share Document