Recycled Concrete Aggregate Classification Based on …
The factors that aect recycled aggregate concrete (RAC) properties are strength, and water absorption of the source concrete (Tavakoli and Soroushian, Kou and Poon 1996a 2011). RCA's controlled water absorption is essential to its workability, mechanical properties, and water-to-cement ratio (Ajdukiewicz and Kliszczewicz 2002). …
Pre-Saturation Technique of the Recycled Aggregates: Solution …
The use of pre-saturated recycled aggregates implied an increase of water in the concrete mixture that leads to a loss in the compressive strength of the recycled concrete. This …
Study on Mechanical Properties of Concrete Using Basalt …
basalt aggregate ranges widely from 0 to 10% [21–27]. Basalt from aggregate quarries has a water absorption of approximately 3%. Recycled aggregate containing basalt exhibits relatively high water absorption; it has higher water absorption than other rock aggregates distributed in the inland areas of Korea (approximately 1%) [28].
M&S highlight: Limbachiya, et al. (2000), Use of recycled aggregate …
The properties of recycled aggregate concrete which are closely related to engineering production were studied in the highlighted paper. Recycled coarse aggregate concrete with different water-cement ratios and different strengths (50 ~ 70 N/mm 2) was studied, and the main mechanical properties and durability of high-performance …
Investigation of Water Absorption Behavior of Recycled Aggregates …
The water–cement ratio (w/c) has a significant effect on the strength of recycled concrete. In this study, considering the effects of water/cement ratio, strength, and water content of recycled aggregates, two kinds of pulse sequences of low-field nuclear magnetic resonance (LF-NMR) were applied to investigate the water migration behavior …
Recycled Concrete Aggregate
Some researchers observed that the water absorption of RCA is 3%–12% higher than that of NA for coarse and fine fractions (Katz, 2003; Martín-Morales et al., 2011). Water …
Feasibility and performance analysis of carbonated recycled aggregate
Rahal (Citation 2007) investigated that for recycled aggregate concrete, the compressive strength was more than 80% as compared to the concrete with natural aggregates, when aggregate's relative water absorption was below 1.8%, whereas for recycled aggregate concrete, the compressive strength was dropped significantly …
Stress–Strain Curve and Carbonation Resistance of Recycled Aggregate
Nevertheless, because of the inferior physical properties of RCA when compared to NCA, such as higher water absorption, higher porosity, lower density and the presence of initial cracks [1,2,3,4], the mechanical properties and durability of RAC are lower than that of natural aggregate concrete (NAC) [5,6,7,8,9].
Quality improvement techniques for recycled aggregates concrete
The quality of the recycled aggregate was improved due to microbial precipitation, which reduced the water absorption of the recycled aggregate [22], [23]. ... Nevertheless, concrete made with treated RA has 34.9% and 25.4% higher water absorption at 0.35 and 0.5 w/c ratios respectively. Density and water absorption are …
Measurement of Water Absorption of Recycled Aggregate
Owing to the high absorption capacity of recycled aggregate (RA), it is crucial to accurately measure its saturated-surface-dried water absorption (WSSD), which largely affects an effective water-to-binder ratio of recycled aggregate concrete. In this study, existing measurement methods for the WSSD of RA are extensively reviewed, …
An Experimental Study on Strengthening Recycled Aggregates
However, because of the existence of adhesive mortar at the aggregate surface and numerous pores and cracks in the aggregates, recycled aggregates usually have a high water-absorption rate, a low crushing resistance, and a low apparent density, which severely limit their application [10,11,12]. It is thus valuable to investigate the ...
Surface modification of recycled coarse aggregate based on …
The high porosity of attached mortar on recycled aggregates leads to high water absorption and low strength, which hinders its application efficiency in concrete production. Microbial induced carbonate precipitation is a promising approach for enhancing recycled aggregates.
Water absorption of fine recycled aggregates: effective …
The high absorption of fine recycled aggregates is indicated as the main difference with respect to fine natural aggregates. This property determines the extra …
Influence of Treatment Methods of Recycled Concrete Aggregate …
Worldwide the concrete industry has started embracing the utilization of recycled concrete aggregates (RCAs) resulting from demolition and construction waste as full or partial substituents in the production of high-strength concrete (HSC) due to their economic and environmental benefits. Several parameters were experimentally …
Mechanical performance of recycled aggregate concrete in green …
Recycled aggregate has a high water absorption rate, and more water is often needed to be added to the production. Nie et al. [67] found that when the dosage was , compared with natural aggregate concrete, the water consumption of ordinary quality RCA concrete increased by 12.4%. It is due to a large amount of mortar attached to the ...
Effect of Composite Impregnation on Properties of Recycled …
The experimental results show that the water absorption of recycled coarse aggregate soaked in polyvinyl alcohol solution decreases most significantly, reaching 64.56%. ... The higher water absorption of S2 compared with the other treated samples is due to the organic alkyl groups produced by the silane accumulating in the cracks and …
Properties of Recycled Aggregates | SpringerLink
The water absorption is one of the major differences between natural and recycled aggregates. The water absorption of recycled aggregate is much higher …
Effect of Nano-TiO2 on Capillary Water Absorption of Recycled Aggregate
To improve the durability performance of recycled aggregate concrete in actual use, this paper uses nano-TiO2-modified recycled coarse aggregate to study, through experiments, the effects of nano-TiO2 on the pore distribution of recycled coarse aggregate concrete after freeze–thaw. The capillary-water-absorption law was used as …
Impact of Recycled Aggregate on the Mechanical and …
Due to the high-water absorption of the RAs, RAs are often pre-saturated [25,29,31] in order to obtain the target workability without adding high water amount. However, Hentges et al. [ 73 ] stated that the use of pre saturated aggregates could increase the amount of water and the w/c ratio in cement mixture, thus decreasing its …
A simple method to address the high water absorption of recycled
The high water absorption of recycled concrete aggregates (RCA) can cause a significant reduction in the flow properties of cement-based materials in …
Frontiers | Performance Assessment of Ultra-High Durability Concrete
The water absorption test results confirm the higher absorption of recycled aggregates but also indicate a reduction in water absorption of carbonated aggregates owing to the pore filling by the precipitation of calcium carbonate. This also relates to the higher density determined for the carbonated aggregate.
Effect of plasticizer dosage on properties of multiple recycled
High-quality recycled coarse aggregate (RCA), complying with KS and JIS standards (maximum water absorption of 3% and minimum specific gravity of 2.5), was obtained from a recycling plant. ... Influence of the incorporation of recycled coarse aggregate on water absorption and chloride penetration into concrete. Constr Build …
Enhancement Treatment of Recycled Concrete Aggregate
This adhered mortar is more porous than NA, resulting in RCA's higher porosity and consequently higher water absorption than NA. The water absorption of RA remarkably increased from 1–5% to 3–12% compared to that of NA (Gomez-Soberon, 2002). The adhered mortar content and water-to-cement ratio (W/C) of the original concrete …
New approach in measuring water absorption of recycled …
Unlike ordinary aggregate, recycled aggregate is coated with patches of cement mortar remains that increase water absorption, prolong the mixing time and …
Absorption Variation with Particle Size of Recycled Fine Aggregates
The scarcity of fine natural aggregates and the negative environmental impact of their extraction make it necessary to find new sources of aggregates for the construction industry. The use of recycled aggregates (RA) derived from waste concrete crushing is a viable option for reducing non-renewable raw material consumption. The …
Development of low-carbon recycled aggregate concrete using
The observations of water absorption and concrete density can be seen in Figs. 7 and 8, respectively. Also, adding alccofine to concrete has confirmed improved water absorption and percentage voids (Jindal et al. 2017). The free water in the mix increased due to the higher water absorption property of untreated RCCA, leading to a higher …
Study on Mechanical Properties of Concrete Using Basalt-Based Recycled
Recycled aggregate containing basalt exhibits relatively high water absorption; it has higher water absorption than other rock aggregates distributed in the inland areas of Korea (approximately 1%) . In addition, an increase in specific surface area through the internal and external basalt pores can significantly degrade the quality of …
Properties of Recycled Aggregate Concrete (RAC)
as a high water-absorption rate, low density, low-strength, and poor bond strength with cementing materials [7,8]. Recycled aggregate (RA) consists of crushed solid waste from buildings. RA has many edges and corners and a large proportion of flaky material. There are many shortcomings of RA, therefore improving the mechanical …
Measurement of Water Absorption of Recycled Aggregate
Abstract. Owing to the high absorption capacity of recycled aggregate (RA), it is crucial to accurately measure its saturated-surface-dried water absorption (W SSD ), which largely affects an effective water-to-binder ratio of recycled aggregate concrete. In this study, existing measurement methods for the W SSD of RA are …
The Durability of Recycled Fine Aggregate Concrete: A Review
The water absorption rate of RFA is much higher than that of natural fine aggregate. RF A absorbs water when freshly mixed with concrete, which has an effect on the mechanical