Effect of the Water to Binder Ratio and Ground Fly Ash on Properties of Recycled Aggregate Concrete

Somna, Rattapon; Jaturapitakkul, Chai; Chalee, Wichian; Rattanachu, Pokpong

doi:10.1061/(asce)mt.1943-5533.0000360

Cited by 94 publications

(18 citation statements)

References 28 publications

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“…The low specific gravity (SSD) of the recycled aggregate compared to the natural aggregate was due to the high porosity and low density of the attached mortar on the surface of the old aggregates. 24,25 The specific gravity of TRCA is 5% to 7% greater when compared with RCA, which was similar to the results of Quan et al 26…”

Section: Bulk Density (Dry) and Specific Gravitysupporting

confidence: 87%

Mechanical and Durability Properties of Concrete Produced with Treated Recycled Concrete Aggregate

Bhasya¹,

Bharatkumar²

2018

ACI Materials Journal

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The presence of attached mortar is the main reason for lower quality of recycled concrete aggregate (RCA) compared to that of natural aggregate. Hence, its use is limited up to 30% replacement of natural aggregate at present. The attached mortar of the RCA can be removed by mechanical treatment, acid treatment, thermal treatment (500 to 750°C [932 to 1382°F]), and microwave treatment. There are difficulties-such as achieving high temperature and treating larger quantities of RCA with acid and a microwave oven-in applying these treatments at field level. Hence, the present study focuses on a combination of heating (250°C [482°F]) and mechanical treatment to improve the quality of the RCA. This method removed 70 to 80% of attached mortar of the RCA. Properties of RCA such as bulk density, specific gravity, water absorption, and crushing value were discussed in detail. Post-treatment, it was observed that the properties of treated RCA improved compared to untreated RCA, but still they were found to be poorer than natural aggregate. The experimental studies were carried out to overcome the aforementioned drawbacks of the recycled aggregate concrete by incorporation of mineral admixtures. It was found that the use of mineral admixtures in concrete produced with treated RCA enhances both the mechanical and durability properties. Thus, the concrete produced with treated RCA and mineral admixture will lead to sustainable development.

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Section: Bulk Density (Dry) and Specific Gravitysupporting

confidence: 87%

Mechanical and Durability Properties of Concrete Produced with Treated Recycled Concrete Aggregate

Bhasya¹,

Bharatkumar²

2018

ACI Materials Journal

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“…While significant numbers of articles on properties of concrete containing RCA are available only a few studied the effect of supplementary cementing materials (SCM) in concrete containing RCA (Somna et al, 2012;Berndt, 2009;Corinaldesi and Moriconi, 2009;Tangchirapat et al, 2010;Kou et al, 2007a and2007b). Somna et al (2012) Others have also suggested that lowering the W/B ratio is a way of compensating the loss of strength in recycled aggregate concretes (Hansen and Narud, 1983). Others used fly ash as an addition rather than replacement in recycled aggregate concrete and found that this led to improved concrete performance (Poon et al, 2002 andKou et al, 2007b).…”

Section: N O T C O P Y E D I T E Dmentioning

confidence: 99%

Properties of Concrete Containing Construction and Demolition Wastes and Fly Ash

Shaikh

2013

J. Mater. Civ. Eng.

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This paper reports the properties of concrete containing recycled coarse aggregate (RCA) sources from local construction and demolition (C&D) wastes and fly ash (FA) sourced from Western Australia (WA). The RCA is used as 25, 50, 75 and 100% (by wt.) replacement of natural coarse aggregate (NCA). In addition, the effect of 40% (by wt.) class F fly ash as partial replacement of cement on the properties of recycled aggregate concrete is also evaluated. The properties of concrete evaluated are the compressive strength, indirect tensile strength, flexural strength and water absorption. All properties are measured at 7, 28, 56 and 91 days. The results show that, better compressive, tensile and flexural strength of concrete containing 25% RCA as partial replacement of NCA can be obtained in recycled aggregate concrete. However,in the case of recycled aggregate concretes containing 40% fly ash the compressive strength at later ages such as at 56 and 91 days is increased but the indirect tensile and flexural strengths are decreased at all ages. It is observed that the water absorption is decreased as RCA content increased. It is also observed that the water absorption is decreased significantly in recycled aggregate concretes containing 40% fly ash at all ages.

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“…Previous studies about the mixture proportion of RCAC mostly focus on the following aspects: The effect of RCA on concrete strength. RCA may lead to 20–25% decrease in compressive strength compared to NCA with the same mixture proportion [15,16,17,18]. The compressive strength of RCAC depends on the RCA properties and RCA replacement ratio [19,20].…”

Section: Introductionmentioning

confidence: 99%

Mixture Proportion Design Method of Steel Fiber Reinforced Recycled Coarse Aggregate Concrete

et al. 2019

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Steel fiber reinforced recycled coarse aggregate concrete (SFRCAC) is an impact minimisation building material. Mixture proportion design method of SFRCAC is developed in this paper to obtain concrete with target strength and workability, which can be used in structural members. Four key parameters of mixture proportioning, steel fiber content, water-cement ratio, water content and sand ratio are discussed through the mixture design tests. The formula for calculating the four key parameters of mixture proportions for SFRCAC are established through the statistical analysis of test results, which mainly consider the influences of recycled coarse aggregate (RCA) replacement ratio and steel fiber characteristic coefficient. The detailed procedure by using the new mixture proportion design method is illustrated with examples. The formulas established have the simple form, reflect the properties of RCA and steel fibers, enhance the mixture proportion design accuracy, and provide the reference for the mix proportion design of SFRCAC.

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Effect of the Water to Binder Ratio and Ground Fly Ash on Properties of Recycled Aggregate Concrete

Cited by 94 publications

References 28 publications

Mechanical and Durability Properties of Concrete Produced with Treated Recycled Concrete Aggregate

Mechanical and Durability Properties of Concrete Produced with Treated Recycled Concrete Aggregate

Properties of Concrete Containing Construction and Demolition Wastes and Fly Ash

Mixture Proportion Design Method of Steel Fiber Reinforced Recycled Coarse Aggregate Concrete

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