Water absorption limits on aggregates
The limits on water absorption effectively rule out the use of recycled aggregates as values of 6-7% are typical and would therefore exclude them from water retaining structures. Similarly this …
Evaluation of strength and absorption behaviour of iron slag …
Construction and demolition waste (CDW), the wastes generated from the demolition of structures, usually include materials like concrete, ceramics, and masonry etc., and also characterised by various heterogeneous compounds such as gypsum, glass, bricks, and wood (Cristelo et al., 2018).Recycling the CDW is the most promising choice for reducing the …
ACI MATERIALS JOURNAL
to 10% when RCA with water absorption limited to 2.5% and an oven-dry specific gravity of over 2500 kg/m3 (156 lb/ft3) is used. Keywords: artificial intelligence; machine learning; modulus of elasticity; neural networks; recycled concrete aggregate; sustainable infrastructure. INTRODUCTION Construction and demolition (C&D) waste accounts for
Prediction of properties of recycled aggregate concrete …
Recycled aggregates include coarse recycled aggregates (CRA) with a typical particle size range of 4.75–31.5 mm and fine recycled aggregates (FRA) between 0.16 and 4.75 mm [27]. Since RA obtained from CDW contains hardened cement paste or mortar and the surface of RA is rough, many micro-cracks will be generated during the crushing process.
Mechanical properties and hydration mechanism of low carbon concrete
The production of construction solid waste has increased with the acceleration of urbanization in various countries around the world. This waste not only occupies land resources but also adversely affects the ecological environment [1, 2].Converting waste concrete into recycled coarse aggregate for secondary utilization is an effective method for the disposal of …
Accelerated carbonation of recycled concrete aggregates: …
In general, recycled aggregates (RA) derived from demolished concrete consist of 65–70 % of natural aggregates and 30–35 % of old cement paste by volume [3].The relative residual cement paste content of RA strongly depend on the porosity of the initial cement paste but it is not significantly affected by the crushing process [4]pared to the typical natural …
Recycled Concrete Aggregates: A Review | International …
Porosity and water absorption are related aggregate characteristics, also attributed to residual mortar. NA generally has low water absorption due to low porosity, but …
(PDF) Recycled concrete aggregates and their influence on concrete …
This monograph addresses the use of recycled concrete aggregates (RCA) as a replacement for natural aggregates (NA) in concrete applications. It aims to provide information and perspectives on ...
Multi-faceted assessment of microbial-reinforced recycled …
The recycling of construction waste into recycled aggregates for concrete production is highly important for saving resources, protecting the environment, reducing carbon dioxide emissions, and achieving sustainable development of the construction industry [6].However, recycled aggregates have problems such as high porosity [7], [8], high water …
Experimental study and analytical modeling of tensile …
As a typical quasi-brittle failure material, Concrete exhibits much lower tensile properties than compressive properties, with tensile cracking often being the primary failure mode. ... Recycled Aggregate Concrete (RAC 1) faces further limitations due to defects in recycled aggregates (RA 2), such as large pores, high water absorption, low ...
The Chemical-Mineralogical Characterization of …
The incorporation of a recycled concrete aggregate (RCA) as a replacement of natural aggregates (NA) in road construction has been the subject of recent research. This tendency promotes sustainability, but its use depends …
Water absorption variability of recycled concrete aggregates …
High water absorption is a typical characteristic of recycled coarse aggregate and is often used to explain the loss of performance of concrete when replacing natural coarse aggregate with recycled coarse aggregate. ... Magazine of Concrete Research Volume 67 Issue 11 Water absorption variability of recycled concrete aggregates Joseph, Boehme ...
Water absorption limits on aggregates
Limits on aggregate water absorption are rare though they may be useful to link to an undesirable concrete property, such as freeze-thaw susceptibility, as water absorption is easily determined. ... The limits on water absorption effectively rule out the use of recycled aggregates as values of 6-7% are typical and would therefore exclude them ...
Use of Recycled Concrete Materials in Base/Subbase …
Recycling Details •Recycling chosen over 3-hour round-trip haul for aggregate. –200,000 gals of fuel saved in hauling aggregate and demolished concrete •Crushing plant set up in interchange cloverleaf. –No crushing from midnight – 6 a.m. –Driver's not allowed to bang tailgates to discharge. 42
Use of Crushed/Recycled Concrete as Drainable …
the recycled concrete. And shall identify location from where concrete will be removed; recycled concrete shall be placed in max 4-in lifts and each lift shall be compacted by a min of 3 passes w/ 10-ton roller (304.3.5) New Jersey Used as Dense-graded aggregate conforms with gradation and plasticity requirements (901.08)
Efficacy of various accelerated carbonation techniques to …
A huge number of research works have been conducted on the utilization of RCA in both structural and non-structural concrete production and those studies indicated that RAC can show enough performance and the researchers have recommended the using of recycled aggregates to a certain amount in replacement of aggregates in concrete [11, 12].At …
Recycled Concrete Aggregates
Water Absorption of Recycled Concrete Aggregates. ... Typical absorption values of between 3% and 10% can be expected and this can be measured and allowed for in the mix design to achieve suitable workability. The moisture …
Assessing benefits of pre-soaked recycled concrete aggregate …
Coarse recycled concrete aggregate (RCA) is a variable material, and that variability can often make it less desirable for usage in concrete infrastructure. ... For reference, the Cement Association of Canada states that the typical absorption capacity range for coarse concrete aggregate is 0.2–4%, and 0.2–2.0% for fine concrete aggregate ...
Performance of concrete containing pristine graphene-treated recycled …
Upcycling recycled coarse aggregates (RCAs) in concrete is a promising way to decrease the environmental effect of construction and demolition waste and improve concrete sustainability.
(PDF) A comparative study of sustainable mix incorporating recycled …
The compressive strength values for typical concrete ... the effects of three recycled concrete materials with different sizes (recycled coarse aggregate (RCA) with a size of 4.75–25 mm ...
Influence of mixed recycled aggregate on the physical – …
This article discusses the findings of a feasibility study on the partial replacement of natural coarse aggregate with a poor quality recycled aggregate from construction and demolition waste in the manufacture of concrete of 30 MPa strength grade. The mixed recycled aggregate used had a high asphalt and floating material content. Workability, density, compressive and …
The adsorption and diffusion behavior of chloride in recycled …
1. Introduction. To implement the system of resource utilization, crushing and reusing discarded concrete has become an important approach. However, the presence of old mortar adhered to the surface of recycled concrete aggregates leads to defects such as high water absorption, high crushing index, rough surface, and high porosity in the RCA [1]. ...
Treatment of recycled concrete aggregate to enhance concrete …
Recycled concrete aggregates (RCA) have received the attention of several researchers over the last few decades to overcome aggregate shortages and to push towards sustainable and environmental-friendly concrete. ... In a typical concrete mixture, aggregates constitute 60% to 75% by volume. ... The reduction in the water absorption by concrete ...
Strength evaluation of utilizing recycled plastic waste and recycled
Table 1 shows the typical chemical properties of crushed glass. Table 1. Chemical properties of crushed ... The water absorption capability of the control concrete sample was compared with other samples with addition of RPW and RCG aggregates. ... the research suggests that incorporating waste plastic and recycled glass in concrete can be a ...
SUSTAINABLE CONSTRUCTION
SUSTAINABLE CONSTRUCTION | A Guide on the Use of Recycled Materials 4 DEFINITION OF TERMS The following terms and definitions are used in this guidebook: • Eco-concrete Eco-concrete is defined as concrete with at least 50% by mass of total aggregate content replaced by recycled materials, used for non-structural applications. Typical
Modeling properties of recycled aggregate concrete …
and plastics are typical types of construction and demolition (C&D) ... it can be graded and utilized as a partial replacement of conventional aggregates. Contrasting natural aggregate (NA) and recycled concrete aggregate (RCA), research shows that mortar adheres to NA more than it does to RCA. This results in higher water absorption, higher ...
The effect of water absorption distribution of recycled coarse
High water absorption is a typical characteristic of recycled coarse aggregate and is often used to explain the loss of performance of concrete when replacing natural coarse aggregate with …
Examining the Influence of Recycled Aggregates on the …
This review examines the impact of recycled aggregates (RAs) on the fresh and mechanical properties of high-strength concrete (HSC). The results revealed that …
Carbonation of Recycled Concrete Aggregates for New …
Abstract: Mineral carbonation provides a way to increase the recycling of concrete waste in added-value products, and contributes to the principles of the circular economy. At present, most concrete waste is still downcycled. The high water absorption of recycled concrete aggregates, among other factors, impedes their recycling in the concrete ...
What is the typical shear strength of RCA (Recycled Concrete …
The shear strength of Recycled Concrete Aggregate (RCA) in concrete structures varies significantly based on the percentage of RCA used and the specific conditions of the concrete mix. Research indicates that while RCA can serve as a sustainable alternative to natural aggregates, its shear strength is generally lower, necessitating careful consideration in …