Mechanical strength and drying shrinkage properties of concrete containing treated coarse recycled concrete aggregates

2014 ◽  
Vol 68 ◽  
pp. 726-739 ◽  
Author(s):  
Sallehan Ismail ◽  
Mahyuddin Ramli
2018 ◽  
Vol 13 (4) ◽  
pp. 39-59 ◽  
Author(s):  
Ali Mardani-Aghabaglou ◽  
Ahsanollah Beglarigale ◽  
Halit Yazıcı ◽  
Kambiz Ramyar

In this study, the effects of recycled glass (RG) and recycled concrete (RC) fine aggregates on the drying-shrinkage, carbonation, high temperature and abrasion resistance of mortar mixtures were investigated comparatively. In addition, durability performance of the mortar mixtures was investigated through micro-structural analysis. For this purpose, 9 different mortar mixtures were prepared by replacing 25, 50, 75 and 100 wt.% of crushed-limestone fine aggregate with recycled glass and recycled concrete aggregates. Except for the abrasion resistance, the RG mixtures showed better durability performance than the control mixture. However, the RC mixtures containing more than 50% recycled aggregate showed lower performance than the control mixture.


2012 ◽  
Vol 548 ◽  
pp. 209-214
Author(s):  
Valeria Corinaldesi ◽  
Giacomo Moriconi

In this paper an investigation of mechanical behaviour and, in particular, elastic properties of recycled aggregate concrete (RAC) is presented. RACs were prepared by using a coarse aggregate made of old concrete particles coming from a recycling plant in which rubble from demolition of reinforced concrete structures is collected and suitably treated. Several concrete mixtures were prepared by using either the only virgin aggregates (as reference) or 30% recycled concrete aggregates replacing gravel, and by using two different kinds of cement. Different water to cement ratios were adopted ranging from 0.40 to 0.60, while concrete workability was always maintained at the same rate by adding different amounts of water-reducing admixture. Concrete compressive strength, elastic modulus and drying shrinkage were evaluated. Results obtained showed that structural concrete up to C32/40 strength class can be manufactured with RAC. Moreover, results obtained were discussed in order to obtain useful information for RAC structure design, particularly in terms of elastic modulus and drying shrinkage prediction.


2018 ◽  
Vol 8 (11) ◽  
pp. 2190 ◽  
Author(s):  
Sungchul Yang

Residual mortar attached to recycled concrete aggregate (RCA) always leads to a decrease in Young’s modulus and an increase in the drying shrinkage of RCA concrete, mainly due to an increase of total mortar volume. To overcome this inherent problem, the modified and equivalent mortar volume (EMV) methods were proposed by researchers. Despite the comparable test results, both models are still subject to the slump loss problem. Thus, under the same W/C (water to cement ratio) ratio and slump condition, this study assessed the influence of the modified EMV mix method on RCA concrete properties. A total of six mixes were proportioned using the modified EMV method with three different RCAs. Test results show that the concrete mixed with RCA produced from old PC concrete sleepers exhibited compressive strength, Young’s modulus, and flexural strength values within 2% variation, equivalent to those values of the companion natural aggregate concrete. In other mixes, compressive strength was found to decrease to 11–20%. It was observed that for 100% replacement of RCA mix, Young’s modulus increased to 10% and drying shrinkage increased to 8% only, while for 50% replacement of RCA mix, Young’s modulus decreased to 8% and drying shrinkage dropped to 4%.


2018 ◽  
Author(s):  
Driton R. Kryeziu ◽  
Armend Muja ◽  
Fisnik Kadiu ◽  
Visar Krelani ◽  
Besian Sinani ◽  
...  

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 209
Author(s):  
Adilson C. Paula Junior ◽  
Cláudia Jacinto ◽  
Thaís M. Oliveira ◽  
Antonio E. Polisseni ◽  
Fabio M. Brum ◽  
...  

The search for environmental preservation and conservation of natural resources gives rise to new concepts and viable technical solutions on the path to sustainable development. In this context, this study’s main objective is to analyse the influence of recycled concrete aggregates (RCAs) on the development of pervious concrete, whose use as a floor covering represents an excellent device to mitigate the urban soil sealing phenomena. For this, mechanical and hydraulic tests were carried out, in addition to microstructural analyses and the assessment of its environmental performance. The results obtained were compared to reference studies also involving the incorporation of recycled aggregates. A pilot-scale case study was conducted, involving a parking space lined with pervious concrete moulded “in situ”. In laboratory tests, permeability coefficients and mechanical strengths compatible with the literature and above the normative limit for light traffic were found. The case study demonstrated higher permeability than in the laboratory, but the flexural strength was lower, being indicated only for pedestrian traffic. The environmental assessment showed that the RCA represents a positive contribution to the environmental performance of pervious concrete. Still, attention should be given to the recycled aggregate transport distance between the concrete plant and the RCA treatment plant.


2019 ◽  
Vol 253 ◽  
pp. 02004
Author(s):  
Wael Alnahhal ◽  
Omar Aljidda

This study investigates the effect of using different volume fractions of basalt macro fibers (BMF) on the flexural behavior of concrete beams made with 100% recycled concrete aggregates (RCA) experimentally. A total of 4 reinforced concrete (RC) beam specimens were flexural tested until failure. The parameter investigated included the BMF volume fraction (0%, 0.5%, 1%, and 1.5%). The testing results of the specimens were compared to control beam specimen made with no added fibers. The experimental results showed that adding BMF improves the flexural capacity of the tested beams.


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