scholarly journals Use of Prefabrication, Construction and Demolition Wastes as an Aggregate in Vibropressed Precast Concrete Blocks Production

2022 ◽  
Vol 11 (1) ◽  
pp. 20-28
Author(s):  
Grzegorz Łój ◽  
Wiesława Nocuń-Wczelik
Keyword(s):  
Precast Concrete ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Partial Substitution ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Concrete Technology ◽  
Natural Sand ◽  
Natural Aggregate ◽  
Concrete Blocks

The aim of current study was to determine the recycled concrete aggregate (RCA) applicability in the production of concrete mixture for vibropressed concrete blocks. The experiments were focused especially on the crushed waste material from the same concrete elements producing plant.  For this type of precast elements only some finer fractions can be implemented and the “earth-moist” consistency of fresh mixture is required. The series of samples was prepared in which the mixture of natural aggregates was partially or totally substituted by recycled concrete aggregate. The 0/4 RCA fraction, which is usually rejected in ready mix concrete technology, plays a role of 0/2 sand.  The substitution of sand fraction was from 20% to 100% respectively. The substitution of the coarser aggregate fractions by 4/16 RCA was also done. The standard properties of vibropressed elements, such as the degree of densification, the density of material, the compressive and splitting tensile strength and the water absorption capacity according to the relevant standards were determined. The parameters of materials with the natural aggregate substitution by RCA are affected by the ratio of recycled concrete aggregate. In most cases the results do not decline specially from those for reference samples, when only the natural sand (0/2) fraction is substituted by the 0/4 recycled aggregate. As one could expect, as lower the substitution, as better the test results. The partial substitution of natural aggregate by coarser fractions requires experimental verification; over 20% substitution of natural aggregate by 4/8, 8/16 or 0/16 RCA should be excluded.

scholarly journals Influence of Partial Coarse Fraction Substitution of Natural Aggregate by Recycled Concrete Aggregate in Hot Asphalt Mixtures

2019 ◽  
Vol 12 (1) ◽  
pp. 250 ◽  
Author(s):  
Debora Acosta Álvarez ◽  
Anadelys Alonso Aenlle ◽  
Antonio José Tenza-Abril ◽  
Salvador Ivorra
Keyword(s):  
Asphalt Concrete ◽  
Coarse Fraction ◽  
Asphalt Mixtures ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Demolition Waste ◽  
Natural Aggregate

The main objective of this work is to evaluate the properties of hot asphalt mixtures that have been manufactured with different recycled concrete aggregate (RCA) percentages (0%, 20%, 40%, 60% and 80% of the fraction 5–13 mm) and asphalt (4%, 4.5% and 5%). Dense asphalt mixtures were made; partially replacing the natural aggregate (NA) fraction between 5 and 13 mm. Marshall specimens were manufactured to determine the main properties of the asphalt concrete (AC) in terms of density, voids, stability and deformation. Additionally, the optimal asphalt content (OAC) was determined, and measured the water sensibility, the stiffness modulus and the permanent deformation. The results corroborate the potential for using these sources of construction and demolition waste (CDW) as a RCA in asphalt concrete and show that the hot asphalt mixtures with up to 40% substitution of natural aggregate by recycled aggregate in the fraction 5–13 mm present good behavior.

Properties of Dry-Mortar with Recycled Concrete Aggregate and Powder of Crushed Clay Bricks

2011 ◽  
Vol 374-377 ◽  
pp. 1637-1640
Author(s):  
Jian Hua Xue ◽  
Xiao Guang Li ◽  
Yun Xiao Liu ◽  
Qiang Du
Keyword(s):  
Compressive Strength ◽  
Physical And Mechanical Properties ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Mass Ratio ◽  
Clay Brick ◽  
Natural Sand ◽  
Clay Bricks

Recycled concrete aggregate (RCA) and crushed clay bricks (CCB) have been increasingly researched and used in past two decades. However, studies focusing on the properties of dry-mortar with RCA and CCB are very limited. In this research, results from physical and mechanical properties of recycled mortar with fine recycled aggregate (FRA), fine recycled powder (FRP) and crushed clay brick (CCB) were secured. It is shown that sinking degree of FRA mortar can be adjusted in the range of 70-90mm and their water-maintainability is superior to natural sand mortar. However, compressive strength of FRA mortar at various ages decrease, compared to natural sand mortar under the condition of same mixed proportion. Compressive strength of FRA mortar is above 5.0MPa with mass ratio of aggregate to cement lower than 6.0.Workability of FRP and CCB mortar is similar to fly ash mortar and their apparent densities are under the 2.0g/cm3. Compressive strength of FRP and CCB mortar is near to 8.5 MPa at 28 days of age.

scholarly journals Asphalt Mixes Processed with Recycled Concrete Aggregate (RCA) as Partial Replacement of the Natural Aggregate

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4196
Author(s):  
Carlos U. Espino-Gonzalez ◽  
Wilfrido Martinez-Molina ◽  
Elia M. Alonso-Guzman ◽  
Hugo L. Chavez-Garcia ◽  
Mauricio Arreola-Sanchez ◽  
...  
Keyword(s):  
Research Work ◽  
Construction Materials ◽  
Recycled Concrete ◽  
International Standards ◽  
Partial Substitution ◽  
Partial Replacement ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Asphalt Mixes ◽  
Natural Aggregate

Materials play a fundamental role in any branch of civil engineering. From ancient times to the present day, society has required enormous amounts of construction materials, which implies an excessive exploitation of the natural environment. The present research work consisted in the design and development of asphalt mixes with a partial substitution of the natural aggregate (NA) by means of recycled concrete aggregate (RCA). The mix was designed with the Marshall methodology, considering the next percentages of substitution and addition by mass: 90% NA and 10% RCA; 80% NA and 20% RCA; 70% NA and 30% RCA. The mixtures were elaborated and analysed under the international standards and the Mexican regulation of the Communications and Transport Ministry, to determine the best option regarding their performance. The materials were characterized according to the current regulations and later employed in the mixes design. A total of 38 specimens were elaborated for each mixture, determining the optimum asphalt content; after that, mechanical tests were performed to analyse and determine the best results. In the aftermath of the examination of all mixtures, we concluded that the 70%AN/30%RCA is the best alternative option according to its performance and numeric results, complying with the cited regulations, and allowing a lower content of asphalt during the process.

scholarly journals The influence of RCA addition on selected parameters of concrete

2018 ◽  
Vol 196 ◽  
pp. 02018
Author(s):  
Roman Jaskulski ◽  
Marcin Supera ◽  
Wojciech Kubissa ◽  
Peter Koteš ◽  
Miroslav Brodňan
Keyword(s):  
Coarse Aggregate ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Test Results ◽  
Recycled Concrete Aggregate ◽  
Average Quality ◽  
Durability Test ◽  
Natural Aggregate ◽  
Concrete Mixtures

The main goal of this research was to evaluate the effects of using recycled concrete aggregate (RCA) of an average quality as a 50% replacement for natural coarse aggregate. A total of 26 concrete mixtures were prepared, 13 containing RCA as a 50% of coarse aggregate and the same number of mixes only with natural aggregate (NA). The results show the influence of the RCA incorporation on concretes for the same w/c ratio. Both mechanical and durability parameters of the concretes made with recycled aggregate are worse, and the differences increase for low w/c ratio. Despite the reduction of these parameters in relation to concretes with only NA, both mechanical and durability test results obtained for concrete series with RCA can be described as good.

A review of experimental results on structural performance of reinforced recycled aggregate concrete beams and columns

2020 ◽  
Vol 23 (15) ◽  
pp. 3351-3369 ◽  
Author(s):  
Simret T Deresa ◽  
Jinjun Xu ◽  
Cristoforo Demartino ◽  
YeongAe Heo ◽  
Zhi Li ◽  
...  
Keyword(s):  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Experimental Results ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Aggregate Concrete ◽  
Natural Aggregate

This article presents a comprehensive and critical review of the structural performances of reinforced recycled aggregate concrete beams and columns based on experimental results reported in the literature. Extensive data sets collected from the literature are categorized to investigate the effects on the local and global structural behavior. First, the flexural and shear response of reinforced recycled aggregate concrete beams is discussed. The structural performances are reviewed focusing on the main geometric and material variables such as the recycled concrete aggregate replacement ratio, the longitudinal reinforcement ratio, the transverse reinforcement ratio, and the shear span-to-depth ratio. Then, the behavior of reinforced recycled aggregate concrete columns under concentric and eccentric compressive loads and the seismic performance under low cyclic loading are discussed. The similarities and the differences between reinforced recycled aggregate concrete and reinforced natural aggregate concrete beams and columns are highlighted. The need for further research is pointed out at the end of the article. The results reported in this review clearly indicate that reinforced recycled aggregate concrete beams and columns with various recycled concrete aggregate replacement ratios have comparable or slightly lower structural performances to the reinforced natural aggregate concrete ones indicating the feasibility of recycled concrete aggregate for structural applications.

Recycling of Waste Concrete and Fly Ash for Recycled Aggregate Concrete: Fundamental Characteristics Evaluation

2009 ◽  
Vol 620-622 ◽  
pp. 255-258 ◽  
Author(s):  
Cheol Woo Park
Keyword(s):  
Fly Ash ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Experimental Program ◽  
Concrete Aggregate ◽  
Fine Aggregate ◽  
Recycled Concrete Aggregate ◽  
Aggregate Concrete ◽  
Waste Concrete

As the amount of waste concrete has been increased and recycling technique advances, this study investigates the applicability of recycled concrete aggregate for concrete structures. In addition fly ash, the industrial by-product, was considered in the concrete mix. Experimental program performed compressive strength and chloride penetration resistance tests with various replacement levels of fine recycled concrete aggregate and fly ash. In most case, the design strength, 40MPa, was obtained. It was known that the replacement of the fine aggregate with fine RCA may have greater influence on the strength development rather than the addition of fly ash. It is recommended that when complete coarse aggregate is replaced with RCA the fine RCA replacement should be less than 60%. The recycled aggregate concrete can achieve sufficient resistance to the chloride ion penetration and the resistance can be more effectively controlled by adding fly ash. It I finally conclude that the recycled concrete aggregate can be successfully used in the construction field and the recycling rate of waste concrete and flay ash should be increased without causing significant engineering problems.

scholarly journals Effects of pre-wetting aggregate on the properties of mortars made with recycled concrete and lightweight aggregates

2019 ◽  
Vol 24 (2) ◽  
Author(s):  
Lidiane Fernanda Jochem ◽  
Diego Aponte ◽  
Marilda Barra Bizinotto ◽  
Janaíde Cavalcante Rocha
Keyword(s):  
Lightweight Aggregate ◽  
Heat Of Hydration ◽  
Recycled Concrete ◽  
Partial Replacement ◽  
Dry Density ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Natural Aggregate ◽  
Entrained Air ◽  
Dimensional Instability

ABSTRACT This paper examines the suitability of partially replacing natural aggregate, sand, (NA) with recycled concrete aggregate (RCA) or lightweight aggregate (LWA) in mortars, under the hypothesis that pre-wetting aggregates would produce improvement in mortar properties. Fresh mortar properties such as density, entrained air content, consistency and heat of hydration, as well as hardened mortar properties such as dry density, compressive and flexural strength, and dimensional instability at 0% and 100% saturation were determined. The results show that mortars made with natural aggregate (75%) and recycled concrete aggregate (25%) have similar properties to mortars made with only natural aggregate (100%) and that pre-wetting the aggregates does not influence the properties of mortars significantly. Therefore, partial replacement with recycled concrete aggregate is a viable alternative for producing mortar.

Research on Mixture Ratio of Recycled Concrete Aggregate in Concrete

2012 ◽  
Vol 193-194 ◽  
pp. 1371-1375
Author(s):  
Yong San Cheng ◽  
Ke Qiang Yu ◽  
Shuang Xi Wang
Keyword(s):  
Mechanical Properties ◽  
Experimental Investigation ◽  
Raw Materials ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Mixture Ratio

In order to better understand the recycled concrete aggregate, it is essential to investigate the different mixture ratio in it. For determining the better mixture ratio of recycled concrete aggregate, the experimental investigation was conducted by making use of recycled concrete aggregate of different ratio instead of small stones in concrete, while maintaining the proportion of other raw materials of concrete unchanged. Its mechanical properties were also investigated. It is found that the better materials proportion of recycled concrete is that sand: recycled aggregate: water= 1: 1.8 : 2.1: 0.55.

Literature Review of Recycled Concrete Aggregate

2014 ◽  
Vol 638-640 ◽  
pp. 1162-1165
Author(s):  
Feng Xu
Keyword(s):  
Sustainable Development ◽  
Literature Review ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Cement Concrete ◽  
Concrete Construction ◽  
The Sustainable Development ◽  
And Performance

Make old cement concrete as recycled aggregate can not only protect environment, saving resources, but also can reduce the project cost, and promoting the sustainable development. This paper based on the related recycled concrete aggregate (RCA Recycled Concrete Aggregate) literature, mainly involve its properties, preparation and performance of RCA concrete, construction application etc..This has got a lot of reliable conclusions, so as to give some inspiration and help to the related scholars.

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