Influence of Wetting and Drying Cycles on Physical and Mechanical Behavior of Recycled Aggregate Concrete

Recently, concerns have been rising about the impact of increasing the depletion of natural resources and the relevant generation of construction and demolition waste, on the environment and economy. Therefore, several efforts have been made to promote sustainable efficiency in the construction industry and the use of recycled aggregates derived from concrete debris for new concrete mixtures (leading to so-called recycled aggregate concrete, RAC) is one of the most promising solutions. Unfortunately, there are still gaps in knowledge regarding the durability performances of RAC. In this study, we investigate durability of structural RAC subjected to wet-dry cycles. We analyze the results of an experimental campaign aimed at evaluating the degradation process induced by wetting and drying cycles on the key physical and mechanical properties of normal- and high-strength concrete, produced with coarse recycled concrete aggregates (RCAs) of different sizes and origins. On the basis of the results we propose a degradation law for wetting and drying cycles, which explicitly makes a possible correlation between the initial concrete porosity, directly related to the specific properties of the RCAs and the resulting level of damage obtained in RAC samples.

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PROPERTIES OF RECYCLED AGGREGATE CONCRETE

Contemporary Materials ◽

10.7251/comen1402239m ◽

2014 ◽

Vol 5 (2) ◽

Author(s):

Mirjana Malešev ◽

Vlastimir Radonjanin ◽

Gordana Broćeta

Keyword(s):

Great Powers ◽

Recycled Concrete ◽

Recycled Aggregate Concrete ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Concrete Aggregate ◽

Demolition Waste ◽

Aggregate Concrete ◽

Recycling Industry ◽

Concrete Mixtures

Following an example of the world's great powers that developed the recycling industry after natural disasters and wars, the paper points to the possibility of using large quantities of construction and demolition waste, generated as a result of the recent floods in the BiH and Serbia. Based on the years of extensive experimental research, and the research conducted by eminent experts, an overview is provided of the most basic properties and application of recycled aggregate concrete. It has been shown that the application of coarse recycled concrete aggregate, as the component materials in the concrete mixtures, it is possible to produce structural concrete that can be satisfactory and even with high quality, which primarily depends on the characteristics of crushed demolished concrete.

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A Novel Conceptual Approach for Predicting the Mechanical Properties of Recycled Aggregate Concrete

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.847.156 ◽

2016 ◽

Vol 847 ◽

pp. 156-165

Author(s):

Marco Pepe ◽

Eduardus Koenders ◽

Romildo Dias Toledo Filho ◽

Enzo Martinelli

Keyword(s):

Mechanical Properties ◽

Recycled Concrete ◽

Recycled Aggregate Concrete ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Recycled Aggregates ◽

Conceptual Approach ◽

Demolition Waste ◽

Predictive Capacity ◽

Moisture Condition

The construction sector is more and more committed to reduce its environmental impacts. One of the key actions undertaken in the last decade deals with the ability of turning construction and demolition waste into new raw materials. For instance, the use of recycled aggregates for producing new concrete was one of the most investigated. Thus, in the last decade, plenty of researches were involved in project on characterising the mechanical behaviour of concrete made with recycled aggregates. However, these projects were mainly experimental in nature and generally led to merely empirical formulations. Conversely, this paper is intended at providing a contribution for predicting the mechanical properties of Recycled Aggregates Concrete (RAC). Particularly, it aims at quantifying the effect of replacing ordinary aggregates with Recycled Concrete Aggregates (RCA) on the resulting compressive strength of RAC. To this end, a conceptual model considering both the relevant physical properties of regular and recycled aggregates, including the attached mortar content, and the hydration reactions of Portland cement paste is proposed. The actual predictive capacity of the proposed model is assessed through an experimental validation against experimental tests carried out on several concrete batches produced with various values for the different keys parameters, such as the nominal water-to-cement ratio, the aggregates replacement ratio and the initial moisture condition of aggregates. Both the experimental data and the theoretical formulations proposed in this paper stem out from the inter-university collaboration developed as part of the EU funded EnCoRe Project (www.encore-fp7.unisa.it).

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The potency of recycled aggregate in new concrete: a review

Construction Innovation ◽

10.1108/ci-07-2018-0056 ◽

2019 ◽

Vol 19 (4) ◽

pp. 594-613 ◽

Cited By ~ 3

Author(s):

Emmanuel Ejiofor Anike ◽

Messaoud Saidani ◽

Eshmaiel Ganjian ◽

Mark Tyrer ◽

Adegoke Omotayo Olubanwo

Keyword(s):

Research Work ◽

Recycled Aggregate Concrete ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Mix Design ◽

Recycled Aggregates ◽

Demolition Waste ◽

Aggregate Concrete ◽

Content Type ◽

Natural Aggregate

Purpose This paper aims to review the effect of using recycled aggregates (RA) on the properties of recycled aggregate concrete (RAC) following the steady rise in global demand for concrete and the large generation of construction and demolition waste. Design/methodology/approach This study reviewed relevant literature of research work carried out by previous researchers, leading to a deeper understanding of the properties of both RA and RAC. The properties of RA and RAC reported in the various studies were then compared to their corresponding natural aggregate (NA) and natural aggregate concrete, as well as the specifications provided in different codes of practice. In addition, the mix design methods appropriate to RAC and the cost implication of using RA were reviewed. Findings Findings show that the contribution of RA to strength appears inferior in comparison to NA. The shortcoming is attributed to the mortar attached to the RA, which raises its water absorption capacity and lowers its density relative to those of NA. However, it has been reported that the use of regulated quantity of RA, new mixing and proportioning methods, the addition of admixtures and strengthening materials such as steel fibres, can improve both mechanical and durability properties of RAC. Cost evaluation also showed that some savings can be realized by using RA instead of NA. Originality/value This research serves as a guide for future works and suggests that the use of RA as aggregate in new concrete is technically possible, depending on the mix design method adopted.

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The Static and the Dynamic Modulus of Elasticity of Recycled Aggregate Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1054.221 ◽

2014 ◽

Vol 1054 ◽

pp. 221-226 ◽

Cited By ~ 5

Author(s):

Tereza Pavlů ◽

Magdaléna Šefflová

Keyword(s):

Modulus Of Elasticity ◽

Dynamic Modulus ◽

Negative Impact ◽

Recycled Concrete ◽

Recycled Aggregate Concrete ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Demolition Waste ◽

Aggregate Concrete ◽

Dynamic Modulus Of Elasticity

The main aim of this contribution is description of the static and the dynamic modulus of elasticity of concrete containing recycled aggregate. Recycled construction and demolition waste, especially recycled concrete, is able to use as an aggregate for concrete, but using of recycled aggregate has a negative impact of concrete characteristic. This paper presents results of non-destructive measurement of recycled aggregate concrete properties. Series of concrete samples with 100% replacement ratios of coarse natural aggregate by coarse recycled aggregate from different sources were prepared for this study. The static and the dynamic modulus of elasticity were investigated on specimens 100 x 100 x 400 mm. All tested mixtures were also tested on compressive strength.

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Mechanical Strength Study on C&D Aggregates Replaced Concrete

Recent Advancements in Geotechnical Engineering ◽

10.21741/9781644901618-18 ◽

2021 ◽

Keyword(s):

Compressive Strength ◽

Recycled Concrete ◽

Recycled Aggregate Concrete ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Recycled Aggregates ◽

Steam Curing ◽

Demolition Waste ◽

Large Size ◽

New Treatments

Abstract. Recycled concrete was produced to overcome the problem of disposal of construction and demolition waste and lack of availability of natural materials. To improve the characteristics of recycled concrete, new treatments and suggestions were given by the researchers. This paper investigates the compressive strength of recycled aggregate concrete having the replacement of 0, 30, 40, 50 & 60% recycled coarse aggregates. The compressive strength of recycled concrete in water curing is compared with steam curing. The compressive strength of concrete is not much affected because of the use of large size recycled aggregates. The use of saturated dried surface large size recycled aggregates improves the strength of concrete.

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Durability of Structural Recycled Aggregate Concrete Subjected to Freeze-Thaw Cycles

Sustainability ◽

10.3390/su12166475 ◽

2020 ◽

Vol 12 (16) ◽

pp. 6475 ◽

Cited By ~ 3

Author(s):

Caroline Santana Rangel ◽

Mayara Amario ◽

Marco Pepe ◽

Enzo Martinelli ◽

Romildo Dias Toledo Filho

Keyword(s):

Physical And Mechanical Properties ◽

Recycled Concrete ◽

Recycled Aggregate Concrete ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Concrete Aggregate ◽

Demolition Waste ◽

Aggregate Concrete ◽

Damage Level ◽

Freeze Thaw

The increasing global demand for natural resources and the extensive production of construction and demolition waste (CDW) raise concerns for both the economic and environmental consequences that they can induce. Several efforts are being made with the aim to promote sustainable practices in the construction industry. In this context, one of the most relevant options refers to reusing CDW in new construction: specifically, the use of recycled concrete aggregate (RCA) is attracting a growing interest. Unfortunately, although the behavior of recycled aggregate concrete (RAC) has been widely investigated in the last few years, there are still knowledge gaps to fill on various aspects of the RAC performance, such as its durability in extreme conditions. The present study deals with the freeze-thaw performance of normal- (C35) and high-strength (C60) RAC produced with RCAs derived from different sources. Specifically, ten concrete mixtures were subjected to a different number of freeze-thaw cycles (namely, 0, 150 and 300), with the aim of analyzing the degradation of key physical and mechanical properties, such density, compressive strength, elastic modulus and tensile strength. Based on the obtained experimental results, a novel degradation law for freeze-thaw cycles is proposed: it unveils a relationship between open porosity of concrete, which is directly correlated to the peculiar properties of RCAs, and the corresponding damage level determined on RAC specimens.

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Sustainable Masonry Made from Recycled Aggregates: LCA Case Study

Sustainability ◽

10.3390/su12041581 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1581 ◽

Cited By ~ 2

Author(s):

Jan Pešta ◽

Tereza Pavlů ◽

Kristina Fořtová ◽

Vladimír Kočí

Keyword(s):

Recycled Concrete ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Recycled Aggregates ◽

Mechanical And Thermal Properties ◽

Concrete Wall ◽

Demolition Waste ◽

Concrete Construction ◽

Characterization Methods ◽

The Impact

For a sustainable building industry, reusable construction with a low demand for primary resources is needed. Moreover, if we want to reduce the amount of construction and demolition waste, construction with recycled aggregate should be considered. To investigate the environmental impacts of such concrete construction, life cycle assessment (LCA) was used to compare the following types of concrete construction: Reusable blocks with recycled brick aggregate, reusable blocks with recycled concrete, reusable blocks with natural aggregate, and regular concrete wall. Firstly, the properties of new concrete with recycled aggregate were measured, such as physical, mechanical, and thermal properties. Then, different constructions were designed and assessed using the method of Institute of Environmental Sciences (CML2001) and the method of National Institute for Public Health and the Environment (ReCiPe 2016) as characterization methods. Unsurprisingly, the regular concrete wall had a higher impact on most of the impact categories, e.g., 113 kg CO2 eq. (in the first scenario, using CML2001). In accordance with the circular principles, the reusability of blocks and recycling of aggregate are the main factors that affect the environmental impact of the constructions. Thus, the global warming potential (GWP) of construction with reusable recycled concrete blocks was only 53 kg CO2 eq. (in the second scenario). Moreover, we show differences in the results of CML2001 and ReCiPe 2016, e.g., in the Photochemical Oxidant Creation category.

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Experimental Study on the Mechanical Properties and Compression Size Effect of Recycled Aggregate Concrete

Materials ◽

10.3390/ma14092323 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2323

Author(s):

Yubing Du ◽

Zhiqing Zhao ◽

Qiang Xiao ◽

Feiting Shi ◽

Jianming Yang ◽

...

Keyword(s):

Mechanical Properties ◽

Size Effect ◽

Compressive Stress ◽

Failure Modes ◽

Recycled Concrete ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Aggregate Concrete ◽

Substitution Ratio ◽

The Impact

To explore the basic mechanical properties and size effects of recycled aggregate concrete (RAC) with different substitution ratios of coarse recycled concrete aggregates (CRCAs) to replace natural coarse aggregates (NCA), the failure modes and mechanical parameters of RAC under different loading conditions including compression, splitting tensile resistance and direct shear were compared and analyzed. The conclusions drawn are as follows: the failure mechanisms of concrete with different substitution ratios of CRCAs are similar; with the increase in substitution ratio, the peak compressive stress and peak tensile stress of RAC decrease gradually, the splitting limit displacement decreases, and the splitting tensile modulus slightly increases; with the increase in the concrete cube’s side length, the peak compressive stress of RAC declines gradually, but the integrity after compression is gradually improved; and the increase in the substitution ratio of the recycled aggregate reduces the impact of the size effect on the peak compressive stress of RAC. Furthermore, an influence equation of the coupling effect of the substitution ratio and size effect on the peak compressive stress of RAC was quantitatively established. The research results are of great significance for the engineering application of RAC and the strength selection of RAC structure design.

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Effects of Recycled Aggregate Resin (RAR) in Concrete Material

International Journal of Sustainable Construction Engineering Technology ◽

10.30880/ijscet.2020.11.02.006 ◽

2020 ◽

Vol 11 (2) ◽

Author(s):

Sharifah Salwa Mohd Zuki ◽

◽

Shahiron Shahidan ◽

Shivaraj Subramaniam ◽

◽

...

Keyword(s):

Epoxy Resin ◽

Recycled Aggregate Concrete ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Engineering Properties ◽

Recycled Aggregates ◽

Hardened Concrete ◽

Demolition Waste ◽

Split Tensile Strength ◽

Close Proximity

This paper discussed the recycled aggregates produced from construction and demolition waste and their utilization in concrete construction. Along with a brief overview of the engineering properties of recycled aggregates, the paper also summarizes the effect and use of recycled aggregates on the properties of fresh and hardened concrete. The recycled aggregates were treated with epoxy resin to reduce the water absorptions with different percentages of resin such as 0%, 25%, 50%, 75%, and 100%. Epoxy resin is widely used in recent years owing to the enhancing of mechanical and durability of the concrete. This research also showed, recycled aggregate concrete are close proximity to normal concrete in terms of split tensile strength, compression strength and wet density. The low usage of resin was obtained good strength concrete compared to high percentage contained treated aggregates due to low bonding between material.

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Analysis of Compressive Fatigue Failure of Recycled Aggregate Concrete

Materials ◽

10.3390/ma14164620 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4620

Author(s):

Fan You ◽

Surong Luo ◽

Jianlan Zheng ◽

Kaibin Lin

Keyword(s):

Fatigue Life ◽

Fatigue Failure ◽

High Cycle Fatigue ◽

Fatigue Behavior ◽

Recycled Aggregate Concrete ◽

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Cycle Fatigue ◽

Demolition Waste ◽

Aggregate Concrete

Using recycled aggregate in concrete is effective in recycling construction and demolition waste. It is of critical significance to understand the fatigue properties of recycled aggregate concrete (RAC) to implement it safely in structures subjected to repeated or fatigue load. In this study, a series of fatigue tests was performed to investigate the compressive fatigue behavior of RAC. The performance of interfacial transition zones (ITZs) was analyzed by nanoindentation. Moreover, the influence of ITZs on the fatigue life of RAC was discussed. The results showed that the fatigue life of RAC obeyed the Weibull distribution, and the S-N-p equation could be obtained based on the fitting of Weibull parameters. In the high cycle fatigue zone (N≥104), the fatigue life of RAC was lower than that of natural aggregate concrete (NAC) under the same stress level. The fatigue deformation of RAC presented a three-stage deformation regularity, and the maximum deformation at the point of fatigue failure closely matched the monotonic stress-strain envelope. The multiple ITZs matched the weak areas of RAC, and the negative effect of ITZs on the fatigue life of RAC in the high cycle fatigue zone was found to be greater than that of NAC.

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