Properties of Recycled Aggregate Concrete

Malešev, Mirjana; Радоњанин, Властимир; Broćeta, Gordana

doi:10.7251/comen1402239m

Cited by 21 publications

(19 citation statements)

References 6 publications

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“…The densities of these natural materials accord those noted by SI 1045-0 [17]. According to Table 4, the substrate of the waste-based green roof includes CWAs (2385 kg/m 3 [18]), CBA (1340 kg/m 3 [19]), and FAAs (1182 kg/m 3 [20]). FAAs are included in the drainage layer as well.…”

Section: Intensive Green Roofsupporting

confidence: 64%

Combining an Intensive Green Roof with Seismic Retrofitting of Typical Reinforced Concrete Buildings in Israel

2022

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This study suggests an intensive green roof as part of a sustainable and hazard-resistant conceptual design for the retrofitting of old buildings in Israel. The roof is suggested to be built with waste-based materials. A five-story reinforced concrete residential building was retrofitted with: Case 1: concrete wall strengthening (CWS)-conventional concrete + conventional green roof; Case 2: CWS-waste-included concrete + waste-based green roof; Case 3: seismic isolation columns (SIC)-conventional concrete + conventional green roof; and Case 4: SIC-waste-included concrete + waste-based green roof. Palekastro, Nuweiba, Tabas, and Erzincan ground motions were used for a structural dynamic time-history analysis of the retrofitted buildings. Life cycle assessments of cases 1–4 were performed using ReCiPe 2016 midpoint and endpoint evaluations. A two-stage analysis of variance (ANOVA) was used to analyze the ReCiPe endpoint results. According to the seismic results, Case 3 and Case 4 were much more preferable to Case 1 and Case 2, whereas according to the environmental evaluations, Case 4 was the most preferable to the other cases.

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Section: Intensive Green Roofsupporting

confidence: 64%

Combining an Intensive Green Roof with Seismic Retrofitting of Typical Reinforced Concrete Buildings in Israel

2022

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“…is is likely to present a significant variation of residual mortar and original virgin aggregate amount, which therefore determines the key properties of RCA [12]. According to Malešev et al [13], the amount of old cement mortar ranges from 25% to 65% by volume of RCA.…”

Section: Introductionmentioning

confidence: 99%

“…e proportion also differs in certain fractions where the smaller the fraction, the greater the amount of cement mortar, as well as the level of water absorption. erefore, the amount of adhered mortar depends mainly on the crushing method during the recycling process [13].…”

Section: Introductionmentioning

confidence: 99%

Contribution of Surface Treatment on Physical and Mechanical Properties of Recycled Concrete Aggregates

Odero¹,

Mutuku

Nyomboi³

et al. 2022

Advances in Civil Engineering

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The demand for virgin aggregates for concrete production worldwide has been increasing. At the same time, there is an increase in the production of rubbles from construction-related activities. The residues are produced either due to leftovers or from the demolished structures. However, worldwide, the utilization of recycled concrete aggregate (RCA) material for structural concrete has been limited, often considered inferior due to distorted surfaces. The problems with RCA arise because it is a composite aggregate made of natural aggregate and cement, and adhered surface mortar is the discontinuities on the surface that arise from the production technique or the strength of the original concrete. The development of hydrated calcium silicate binder in the concrete matrix has been the critical desire of researchers to make better concrete material. This research focuses on the treatment of RCA from locally available rice husk ash with minimum pozzolanic cement. The objective was achieved by conducting tests on the properties of aggregates that include specific gravity and water absorption, aggregate crushing value (ACV), and aggregate impact value (AIV). The effectiveness of the treatment technique is assessed by the analysis of SEM imagery and XRD analysis of the microstructure cement paste around the RCA. At 20% pozzolan concentration, RCA treatment yields comparable specific gravities, water absorption, ACV, and AIV. Furthermore, the replacement of 5% rice husk ash (in 20% concentration) provided the optimal proportion of treatment for RCA, resulting in a reduction of ACV by 31.4%, AIV by 30.0%, and water absorption by 12.7% compared to the untreated RCA. XRD showed that calcite (CaCO₃), quartz, and portlandite phases were the majority in the untreated RCA. The study indicates that pozzolanic cement with 15% can be used with 5% RHA to produce RCA with characteristics almost similar to virgin aggregates. This research presents a consistent methodology to achieve modified RCA for application in construction.

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“…• Inadequate standards regarding recycling aggregate is another problem. According to Malešev et al (2014), recycled aggregate is less advantageous than natural aggregate in terms of physical characteristics. The grains are irregular, mostly angular, rough and with a cracked surface and porous.…”

mentioning

confidence: 99%

“…These grain properties significantly affect the workability of fresh concrete as well as the strength and permeability of the hardened concrete. (Malešev et al, 2014).…”

mentioning

confidence: 99%

Characterization of Coarse Recycled Aggregates Produced from Concretes with Different Strength Levels

Hosseinnezhad

Tosun

Andiç‐Çakır

et al. 2022

Natural and Applied Sciences Journal

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With the acceleration of Urban Renewal Program, particularly in large cities of Turkey, the problem of finding land-fills and eliminating construction waste with the least environmental pollution necessitates its value-added recycling. However, the presence of adhered weak mortar layer, comprising 20-70% of recycled concrete aggregate (RCA), limits the use of RCA or lowers its inclusion level in concrete mixtures. Within the scope of this study, limestone- and basalt-bearing RCA obtained from 6 different concrete mixtures with three different water/cement ratios (0.45, 0.60, 0.70) were prepared and their water absorption, specific gravity, dense and loose unit weight, flatness indices, Los Angeles degradation values were determined. The results showed that, increasing w/c ratio of the parent concrete increased water absorption of the resultant RCA. However, the specific gravity, unit weight, abrasion resistance and flakiness index of RCA were decreased by increasing w/c ratio of the parent concrete.

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Properties of Recycled Aggregate Concrete

Cited by 21 publications

References 6 publications

Combining an Intensive Green Roof with Seismic Retrofitting of Typical Reinforced Concrete Buildings in Israel

Combining an Intensive Green Roof with Seismic Retrofitting of Typical Reinforced Concrete Buildings in Israel

Contribution of Surface Treatment on Physical and Mechanical Properties of Recycled Concrete Aggregates

Characterization of Coarse Recycled Aggregates Produced from Concretes with Different Strength Levels

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