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Open AccessArticle

The Utilization of Recycled Masonry Aggregate and Recycled EPS for Concrete Blocks for Mortarless Masonry

University Centre for Energy Efficient Buildings of Technical University in Prague, Trinecka 1024, 273 43 Bustehrad, Czech Republic
*
Author to whom correspondence should be addressed.
Materials 2019, 12(12), 1923; https://doi.org/10.3390/ma12121923
Received: 30 April 2019 / Revised: 6 June 2019 / Accepted: 11 June 2019 / Published: 14 June 2019
(This article belongs to the Special Issue Environmentally Friendly Renewable Materials)

Abstract

The main aim of this paper is to carry out the environmentally based enhancement of a concrete mixture containing recycled materials whilst considering natural resource consumption as well as mechanical and thermal property levels. The developed concrete is intended to be used in mortarless masonry wall structures. Ten concrete mixtures with different types and replacement rates of recycled masonry aggregate and recycled expanded polystyrene were prepared, and their mechanical and thermal properties were experimentally investigated. It was found that the use of recycled masonry aggregate led to better thermal properties while maintaining sufficient mechanical properties. On the contrary, the addition of recycled expanded polystyrene did not significantly affect the thermal properties of concrete, but the mechanical properties considerably declined. For this reason, the recycled masonry aggregate is suitable to use as an aggregate for concrete masonry blocks for wall structures.
Keywords: recycled masonry aggregate; recycled expanded polystyrene; recycled aggregate concrete; concrete blocks for mortarless masonry; thermal properties; environmentally-based optimization recycled masonry aggregate; recycled expanded polystyrene; recycled aggregate concrete; concrete blocks for mortarless masonry; thermal properties; environmentally-based optimization

1. Introduction

The effective use of construction and demolition waste (CDW) and its application in reusable structural elements can simultaneously reduce waste dumping and decrease the need to use primary resources, both of which are important environmental aspects to be considered in responsible sustainability management. This represents an important contribution to the solution of one of the core objectives of the 2030 UN Agenda on Sustainable Development—Goal 12: Ensure sustainable consumption and production patterns [1]. This goal is focused on economic growth based on efficient resource use and low environmental degradation while improving the well-being of people. This can be done by a shift towards more sustainable resource consumption and improved production processes.
Currently, this is a very real problem, not only from a local/regional perspective, but especially from a global point of view. The material footprint per capita of developing countries almost doubled in the last eight years, representing a significant and needed improvement in material standards of living [1]. Most of this increase is connected with the rising consumption of nonmetallic minerals due to growth in infrastructure and construction. This also includes the environmental impact of concrete structures, which is still growing. Thus, concrete plays an important role in this process and represents a promising challenge for the future.
The replacement of natural aggregate (NA) by recycled aggregate (RA) from construction and demolition waste reduces consumption of primary recourses. However, its utilization mostly negatively affects the properties of concrete. For this reason, the utilization of recycled construction and demolition waste is mostly limited to the use of recycled concrete waste for constructing base layers in road structures or partial replacement of aggregates for concrete. Mixed recycled aggregate (MRA) with a high content of waste masonry has not found satisfactory utilization yet. There are concerns over the quality of recycled masonry as a technological material due to the complexity of the demolition and recycling process. Furthermore, this secondary raw material cannot be used as an aggregate for concrete according to Czech standards [2]. However, the selective demolition and two-phase recycling process leads to higher-quality recycled masonry aggregate (RMA) without the unwanted impurities which negatively influence its properties. Despite the high quality of RMA, its use as an aggregate for recycled aggregate concrete (RAC) negatively influences mechanical properties and durability. However, RMA has a positive impact on thermal properties.
Many studies of the properties of RMA and its effect on the mechanical properties of RAC have been published [3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29]. It has been recognized that RMA differs from NA mainly in terms of water absorption, density, and resistances, for instance, resistance to wear, abrasion resistance, or freeze–thaw resistance [24]. The range of water absorption of coarse RMA has been established from 10% to 19%, which is up to 25 times higher than natural gravel [5,13,22,25], and fine RMA from 12% to 15%, which is more than 10 times higher than natural sand [16,22,30]. The dry density of coarse RMA ranges between 1800 and 2700 kg/m3 and fine RMA between 2000 and 2500 kg/m3, which is generally lower than natural gravel and sand [5,13,16,22,25,26].
The physical, mechanical, thermal, and durability properties of concrete are influenced by the physical, mechanical, thermal, and durability properties of aggregates. The higher water absorption of RMA affects the workability of fresh concrete [30]. For this reason, it is necessary to determine the additional water needed and to add it to the concrete mixture during mixing [16] or to soak RMA in water for 24 h before mixing [22] to achieve workability that is similar to a conventional concrete mixture. Workability and the effective water/cement (w/c) ratio influence the compressive strength of concrete [26]. The effective w/c ratio is the total amount of water which reacts with cement divided by the total amount of cement. For recycled aggregate concrete, this depends on the water absorption capacity of the recycled aggregate [31]. The compressive strength of recycled aggregate concrete decreases with an increasing NA replacement rate [16,22,30]. No significant decline of compressive strength has been found for recycled aggregate concrete with 15% coarse RMA. On the contrary, the compressive strength of concrete with full replacement of coarse NA by RMA decreases up to 35% [22]. The partial replacement of natural sand by fine RMA has had no significant impact on the compressive strength of recycled aggregate concrete. The reason could be the silica and alumina contents in crushed bricks, which could lead to pozzolanic reactions [30].
The thermal conductivity of concrete depends on the type of aggregate [32], its thermal conductivity, as well as the density and porosity of the aggregate [33]. Furthermore, the thermal conductivity of concrete is also strongly influenced by the w/c ratio [34] and cement content [35]. It has been established that lower aggregate thermal conductivity causes lower concrete thermal conductivity. This aspect could positively influence the usability of concrete with RMA due to its lower thermal conductivity caused by the low thermal conductivity of RMA, which ranges between 0.60 and 0.78 W/(m·K) [33]. The thermal conductivity of NA depends on its mineralogical characteristics, composition, and degree of crystallization. The heat conduction of NA with a crystalline structure is higher than amorphous and vitreous NA of the same composition [36].
In order to decrease the thermal conductivity of concrete, various kinds of thermal insulation materials have been added to self-insulating concrete. For instance, expanded polystyrene (EPS) beads, vermiculite, and glazed hollow beads have been used as insulating materials added to concrete. The utilization of thermal insulation materials as partial replacement of sand in concrete mixtures diminishes the mechanical properties, density, and thermal conductivity of concrete. Moreover, the decrease of these properties depends on the type of additional material [37,38,39,40,41,42,43,44,45,46]. The density of self-insulating concrete with recycled EPS ranges from 1070 to 1250 kg/m3, with the thermal conductivity between 0.34 and 0.5 W/(m.K) and compressive strength between 7.74 and 15.55 MPa at 28 days (see Table 1) [37]. In another study [38], two types of lightweight concrete were manufactured. One concrete mixture with a fresh density of 400 kg/m3 was produced with the strength of 3.0 MPa and thermal conductivity 0.09 W/(m.K), and another concrete mixture with a fresh density of 800 kg/m3 was produced with the strength of 13.0 MPa and thermal conductivity 0.25 W/(m.K). Polystyrene foamed concretes of densities ranging from 150 to 1200 kg/m3 with an EPS volume between 0% and 82% were compared with foamed concrete of 800 kg/m3 density without EPS [39]. The results of this study indicated a significant decline of compressive strength and a reduction of thermal conductivity caused by the increased EPS content. The concrete mixture containing 45% EPS had compressive strength of about 0.85 MPa and thermal conductivity of 0.16 W/(m·K), while the concrete mixture with 82% EPS had compressive strength of 0.08 MPa and thermal conductivity of 0.08 W/(m·K). Recycled EPS can be also used as a partial replacement of aggregate in self-insulating concrete for structural utilization [40].
Research on recycled materials as a partial or full replacement of NA in structural applications such as concrete blocks, paving blocks or floor blocks has already been published. The main reason for replacement of aggregate, which is the major component in concrete blocks, is the primary sources savings [50]. There are many recycled waste materials which is possible to use as partial or full replacement of aggregate in concrete blocks such as recycled concrete waste [51,52,53,54,55,56,57], crushed brick waste [11,58,59,60,61,62,63,64,65,66], glass waste [67,68,69,70], crump rubber waste [71,72,73], ceramic and tile industry waste [74], marble waste [75,76], plastic waste [77] and concrete slurry waste [78,79]. Moreover, due to its unique characteristics, the recycled materials could positively influence some properties of concrete blocks such as thermal conductivity, thermal resistance [65] or mechanical properties [67].
The use of RMA as a partial or full replacement of aggregate in structural concrete was examined for manufacturing precast prestressed beams [11], paving with precast concrete [58], and paving blocks or hollow tiles [59]. It was found that the most affected property of concrete was the modulus of elasticity, while compressive and tensile strengths were maintained at acceptable values for the full replacement of NA. The maximal acceptable replacement rate of RMA was found to be up to 35% for concrete with RMA in precast prestressed joists of building floors. Recycled aggregates from CDW containing more than 50% of waste concrete, more than 20% of waste clay bricks, and around 20% of cement or mortar stone were also used as a partial replacement of natural aggregates for preparing concrete masonry blocks suitable for indoor applications [60,61]. In this research, full blocks of 95% RA and hollow blocks of 75% RA were manufactured and tested.
This paper presents the environmentally based optimization of a concrete mixture containing recycled materials for mortarless masonry wall structures. Due to the low thermal conductivity of RMA and EPS, their utilization could have great potential for manufacturing concrete blocks for mortarless masonry walls of low-rise buildings, despite the decline of strength. From technical and/or economic viewpoints, the principle of mortarless masonry permits easy wall deconstruction for the most effective reuse of structural elements after their end of life.

2. Materials and Methods

In total, 10 concrete mixtures were prepared and tested in order to verify the properties of concrete made using recycled masonry aggregate. One of them was a reference mixture with a natural aggregate only, and other mixtures contained recycled masonry aggregate and recycled expanded polystyrene in various ratios as a partial or full replacement of natural aggregate.

2.1. Recycled Aggregate

This research used one type of NA, two types of RMA, and one type of recycled EPS. Both types of RMA originated from construction and demolition waste and were delivered in fractions of 0–8 and 8–16 mm by a Czech recycling center (see Figure 1). For utilization as a substitute for fine-grained aggregate, in mixtures with an aggregate of fraction 0–16 mm in various replacement ratios, the fractions 0–4 and 4–8 mm were separated from the aggregate of fraction 0–8 mm in the laboratory. For mixtures containing a 0–8 mm fraction, RMA 0–8 mm was used without any laboratory treatment. Physical properties of RMA, especially water absorption, differ from NA. Therefore, the physical properties (see Table 2) are presented to show the differences in the materials used for the preparation of the concrete mixtures.
Selected properties of RMA were tested according to valid Czech standards. The properties most influencing the recipe design were tested. The basic physical properties of RMA are shown in Table 2, the granulometry is shown in graphs in Figure 2, and the composition of RMA is listed in Table 3.

2.2. Recycled Aggregate Concrete Mixtures

Ten concrete mixtures with the same exposition class XF1, effective w/c ratio 0.5, and amount of cement CEM I 42.5 R 320 kg/m3 were prepared for laboratory measurements. One mixture of conventional concrete of strength class C30/37 only with NA of fraction 0–16 mm was manufactured as a reference to compare with the other mixtures in which NA was replaced in various ratios by RMA (five mixtures) and recycled EPS in addition (four mixtures). Two mixtures of RMA concrete (RMAC E and RMAC EPS D) only with RMA of fraction 0–8 mm was manufactured (see Table 4). The sample fragments of each material and the composition of RMA concrete mixtures are shown in Table 5 and Figure 3.
The physical, mechanical, deformation, and thermal properties were tested according to valid Czech standards. Samples of dimensions 100 × 100 × 400 mm, 150 × 150 × 150 mm, and 100 × 100 × 100 mm were used for testing.

2.3. Evaluation Methodology

Samples were stored and cured in a stable laboratory environment during solidification and maturation, and after 28 days, the following properties were determined by laboratory tests: physical (density and capillary absorption), mechanical (compressive strength and tensile strength), deformation (static modulus of elasticity in compression), and thermal (volume heat capacity and thermal conductivity).
The mechanical properties, such as compressive strength, flexural strength, and static modulus of elasticity, were examined according to European and Czech standards. Water absorption capacity by immersion was tested on cubic specimens 100 × 100 × 100 mm. Specimens were treated by water, and after stabilization of weight, dried in an oven at a temperature of 105 ± 2 °C until stabilization of weight. The saturated surface-dried density and dry density were measured on these samples. Capillary water absorption was determined by measuring the rate of water absorption by capillaries. The ends of fractured prismatic specimens of 100 × 100 × approx. 150 mm, which were tested after the tensile strength test, were immersed in water up to a maximum height of 5 mm for 72 h or until their weight stabilized. The amount of water absorbed at different time intervals was measured by periodically weighing the surface-dried sample. Weighing intervals were 5 min, then 15 min for the first hour, then every hour for the first 6 h, and finally, every 12 h.
Measurement of thermal properties was done by the portable hand-held system ISOMET 2114 (Applied Precision Ltd., Bratislava, Slovakia) for measurement of the heat transfer properties of the materials. This applies a dynamic measurement method, which enables reducing the measurement time in comparison with steady-state measurement methods. It is equipped with a surface probe for measuring solid and hard materials. A flat surface of at least 60 mm diameter is satisfactory for the probe. Demand for the accuracy of the surface flatness increases as the thermal conductivity value of the tested material increases. The expected minimal thickness of the evaluated materials ranged from 20 to 40 mm depending on their diffusivity (conductivity).
Measured quantities and measurement ranges:
  • Thermal conductivity λ (W/(m·K)): 0.04–6.00;
  • Thermal diffusivity a (m2/s);
  • Volume heat capacity cρ (J/(m3·K)): 4.0 × 104 to 3.0 × 106;
  • Temperature T (°C): −15 to +50.
The thermal properties were tested on three cube samples of concrete of dimensions 100 × 100 × 100 mm for each mixture (see Table 3). The samples were tested under constant laboratory conditions. The temperature was 23 ± 3 °C.

3. Results and discussion

3.1. Physical Properties

The water absorption of buildings materials is important to know due to its influence on durability [80,81]. The values of density, water absorption by immersion, and capillary water absorption are shown in Table 6. Test results of the density showed lower values for all tested recycled aggregate concrete mixtures than the reference concrete. The density of recycled aggregate concrete declined with the increasing amount of RMA and EPS. The lowest value of density was measured for a mixture with 30% EPS, with a difference of 33%. The water absorption by immersion was approximately two times higher for the recycled aggregate concrete mixture than the reference concrete. Furthermore, the saturated surface-dried density, which was measured on saturated concrete samples, was the highest for reference mixture and the lowest for the mixture with the highest content of RMA and EPS (see Figure 4). In addition, the results of the capillary water absorption of concrete mixtures with 100% RMA showed similar results. On the contrary, capillary water absorption of concrete mixtures with EPS was mostly lower than that of the reference concrete (see Figure 5). The results of the density and water absorption by immersion confirm the results reported in previous studies [7,80,81,82,83].

3.2. Mechanical and Deformation Properties

The compressive strength is the most important mechanical property of concrete blocks, which can be greatly enhanced by using recycled aggregate. The compressive strength of load-bearing wall blocks should not be less than 7 MPa [84]. The compressive strength and static modulus of elasticity were tested for all concrete mixtures because of their considerable importance for utilization as concrete blocks for wall structures. Further, flexural strength was also tested to better understand these materials. The values of compressive strength, flexural strength, and static modulus of elasticity are shown in Table 7. Test results of the compressive strength showed lower values for all tested RACs in comparison with the reference concrete. The compressive strength of RAC was influenced by the ratio of RMA and EPS. The highest compressive strength of RAC was measured for the concrete mixture with full replacement of aggregate by RMA. On the contrary, the lowest values of compressive strength were for mixtures with EPS (see Figure 6). As reported in previous studies [85,86,87], the static modulus of elasticity is a property that usually shows the greatest difference between natural aggregate concrete (NAC) and recycled aggregate concrete (RAC). The decline for full replacement rates is mostly more than 50%, which applied in this case too.

3.3. Thermal Properties

The lightweight and thermal insulation properties are the important functional characteristics of wall blocks for buildings [50]. The utilization of concrete blocks is not usually popular for wall structures of low-rise buildings due to its higher thermal conductivity, despite it being a material used for better heat stability in buildings. For this reason, it is very suitable to maintain heat capacity while increasing the thermal conductivity of the material. Previous studies found that the utilization of recycled materials such as recycled concrete aggregate [47], crumb rubber waste [72,88] or recycled EPS [40] leads to lower thermal conductivity of the recycled aggregate concrete. For this reason, this finding was also verified with recycled masonry aggregate concrete (RMAC) in this study. It was proved that the utilization of RMA for concrete wall masonry blocks leads to the lower thermal conductivity.
The thermal conductivity of concrete mixtures with RMA was approximately three times lower in comparison with NAC (see Figure 7). The thermal conductivity of concrete is influenced by the replacement rate and type of aggregate. However, the addition of EPS had no significant effect on this property. If 100% of the aggregate is substituted by RMA, the thermal conductivity will be similar to mixtures containing EPS. However, test results of the volume heat capacity showed similar values for all tested concrete mixtures, with the maximal difference up to 10% (see Table 8.).
It was found that the thermal conductivity of concrete slightly depends on its density and compressive strength (see Figure 8 and Figure 9). However, correlations were not as significant as expected. On the contrary, the results showed that the thermal conductivity and density were dependent on the replacement rate of the aggregate in the concrete mixture. The increasing amount of RMA in mixture led to a decrease in thermal conductivity and density (see Figure 10). In conclusion, the results showed that the best mixture in terms of thermal properties, density, and mechanical properties as well as recycled material content was RMAC D, which contained 100% fine and coarse RMA.

4. Conclusion

In this study, the environmental optimization and experimental verification of the physical, mechanical, and thermal properties of concrete containing various amounts of recycled masonry aggregate were examined and discussed. The final conclusions that have been reached can be summarized in the following points:
  • Recycled aggregate concrete has generally higher water absorption compared with conventional concrete. In this case, the water absorption by immersion and capillary water absorption were approximately two times higher. This aspect negatively influences the durability of concrete, especially freeze–thaw resistance. Nevertheless, it is not so important for insulated walls above ground level.
  • The use of recycled masonry aggregate as a partial or full replacement of natural aggregate in concrete mixtures negatively influences the mechanical properties of concrete, such as compressive strength, modulus of elasticity, and so forth. Here, the decline of compressive strength was between 30% and 75% and the decline of static modulus of elasticity was between 42% and 68% depending upon replacement rates.
  • The thermal conductivity of concrete with recycled masonry aggregate was approximately 70% lower than the value of the reference concrete with only a natural aggregate. The utilization of 30% recycled EPS for the concrete mixture with recycled masonry aggregate further decreased the thermal conductivity by about 5%. The volume heat capacity of concrete containing both types of recycled materials was similar to the volume heat capacity of concrete with natural aggregate.
  • The decrease of the thermal conductivity of recycled aggregate concrete depends on the replacement ratio of recycled masonry aggregate in concrete. This dependence applies to the same type and fraction of recycled aggregate.
As it was mentioned in previous studies about concrete blocks with recycled materials, the replacement of aggregate by recycled materials with their unique characteristics can positively influence the properties of concrete blocks for special applications [11,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79]. The test results showed that the use of recycled aggregate as a replacement for natural aggregate in concrete positively influenced the thermal conductivity of concrete, although it negatively influenced the mechanical properties. On one hand, the better thermal conductivity of concrete masonry blocks from recycled aggregate concrete with RMA in comparison with conventional concrete masonry blocks reduces thermal insulation thickness while maintaining the same thermal properties of the structure. This leads to other material savings in addition to natural aggregate savings. On the other hand, maintaining the same mechanical properties might require the use of more cement. For these reasons, it is necessary to find the optimal way to use this type of recycled material. One possibility is using recycled aggregate concrete with recycled masonry aggregate to manufacture concrete blocks for mortarless masonry for low-rise buildings without high mechanical property and durability requirements. Finally, using mortarless masonry increases the potential for concrete masonry blocks to be reused.

Author Contributions

The following statements should be used Conceptualization, T.P.; Methodology, T.P.; Validation, T.P., K.F. and J.D.; Formal Analysis, T.P.; Investigation, T.P. and K.F..; Resources, T.P., Writing-Original Draft Preparation, T.P.; Writing—Review & Editing, T.P. and P.H.; Visualization, T.P. and K.F.; Supervision, P.H.; Project Administration, T.P.

Funding

This research was funded by MPO TRIO FV 10397—RENCO Recycled Environmental Concrete for Building Construction

Acknowledgments

This work has been supported by the Ministry of Education, Youth and Sports within the National Sustainability Programme I. project No. LO1605—University Centre for Energy Efficient Buildings—Sustainability Phase and MPO TRIO FV 10397—RENCO Recycled Environmental Concrete for Building Construction.

Conflicts of Interest

“The authors declare no conflict of interest.” The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results”.

References

  1. Transforming Our World: The 2030 Agenda for Sustainable Development. In A New Era in Global Health; Rosa, W. (Ed.) Springer Publishing Company: New York, NY, USA, 2017; ISBN 978-0-8261-9011-6. [Google Scholar]
  2. CSN EN 206+A1. Concrete: Specification, Performance, Production and Conformity; The European Standard: Prague, Czech Republic, 2018. (In Czech) [Google Scholar]
  3. Pacheco-Torgal, F.; Jalali, S. Compressive strength and durability properties of ceramic wastes based concrete. Mater. Struct. 2011, 44, 155–167. [Google Scholar] [CrossRef]
  4. Senthamarai, R.M.; Devadas Manoharan, P. Concrete with ceramic waste aggregate. Cem. Concr. Compos. 2005, 27, 910–913. [Google Scholar] [CrossRef]
  5. Yang, J.; Du, Q.; Bao, Y. Concrete with recycled concrete aggregate and crushed clay bricks. Constr. Build. Mater. 2011, 25, 1935–1945. [Google Scholar] [CrossRef]
  6. Mansur, M.A.; Wee, T.H.; Lee, S.C. Crushed Bricks as Coarse Aggregate for Concrete. Mater. J. 1999, 96, 478–484. [Google Scholar]
  7. Medina, C.; Sánchez de Rojas, M.I.; Thomas, C.; Polanco, J.A.; Frías, M. Durability of recycled concrete made with recycled ceramic sanitary ware aggregate. Inter-indicator relationships. Constr. Build. Mater. 2016, 105, 480–486. [Google Scholar] [CrossRef]
  8. Vieira, T.; Alves, A.; de Brito, J.; Correia, J.R.; Silva, R.V. Durability-related performance of concrete containing fine recycled aggregates from crushed bricks and sanitary ware. Mater. Des. 2016, 90, 767–776. [Google Scholar]
  9. Correia, J.R.; de Brito, J.; Pereira, A.S. Effects on concrete durability of using recycled ceramic aggregates. Mater. Struct. 2006, 39, 169–177. [Google Scholar] [CrossRef]
  10. Rashid, K.; Razzaq, A.; Ahmad, M.; Rashid, T.; Tariq, S. Experimental and analytical selection of sustainable recycled concrete with ceramic waste aggregate. Constr. Build. Mater. 2017, 154, 829–840. [Google Scholar] [CrossRef]
  11. González, J.S.; Gayarre, F.L.; Pérez, C.L.-C.; Ros, P.S.; López, M.A.S. Influence of recycled brick aggregates on properties of structural concrete for manufacturing precast prestressed beams. Constr. Build. Mater. 2017, 149, 507–514. [Google Scholar] [CrossRef]
  12. Nepomuceno, M.C.S.; Isidoro, R.A.S.; Catarino, J.P.G. Mechanical performance evaluation of concrete made with recycled ceramic coarse aggregates from industrial brick waste. Constr. Build. Mater. 2018, 165, 284–294. [Google Scholar] [CrossRef]
  13. Cachim, P.B. Mechanical properties of brick aggregate concrete. Constr. Build. Mater. 2009, 23, 1292–1297. [Google Scholar] [CrossRef]
  14. Anderson, D.J.; Smith, S.T.; Au, F.T.K. Mechanical properties of concrete utilising waste ceramic as coarse aggregate. Constr. Build. Mater. 2016, 117, 20–28. [Google Scholar] [CrossRef]
  15. Zheng, C.; Lou, C.; Du, G.; Li, X.; Liu, Z.; Li, L. Mechanical properties of recycled concrete with demolished waste concrete aggregate and clay brick aggregate. Results Phys. 2018, 9, 1317–1322. [Google Scholar] [CrossRef]
  16. Alves, A.V.; Vieira, T.F.; de Brito, J.; Correia, J.R. Mechanical properties of structural concrete with fine recycled ceramic aggregates. Constr. Build. Mater. 2014, 64, 103–113. [Google Scholar] [CrossRef]
  17. Nematzadeh, M.; Dashti, J.; Ganjavi, B. Optimizing compressive behavior of concrete containing fine recycled refractory brick aggregate together with calcium aluminate cement and polyvinyl alcohol fibers exposed to acidic environment. Constr. Build. Mater. 2018, 164, 837–849. [Google Scholar] [CrossRef]
  18. Gonzalez-Corominas, A.; Etxeberria, M. Properties of high performance concrete made with recycled fine ceramic and coarse mixed aggregates. Constr. Build. Mater. 2014, 68, 618–626. [Google Scholar] [CrossRef]
  19. Khalaf Fouad, M.; DeVenny Alan, S. Properties of New and Recycled Clay Brick Aggregates for Use in Concrete. J. Mater. Civ. Eng. 2005, 17, 456–464. [Google Scholar] [CrossRef]
  20. Khalaf Fouad, M.; DeVenny Alan, S. Recycling of Demolished Masonry Rubble as Coarse Aggregate in Concrete: Review. J. Mater. Civ. Eng. 2004, 16, 331–340. [Google Scholar] [CrossRef]
  21. Pacheco-Torgal, F.; Jalali, S. Reusing ceramic wastes in concrete. Constr. Build. Mater. 2010, 24, 832–838. [Google Scholar] [CrossRef]
  22. Debieb, F.; Kenai, S. The use of coarse and fine crushed bricks as aggregate in concrete. Constr. Build. Mater. 2008, 22, 886–893. [Google Scholar] [CrossRef]
  23. Devenny, A.; Khalaf, F.M. The use of crushed brick as coarse aggregate in concrete. Mason. Int. 1999, 12, 81–84. [Google Scholar]
  24. Verian, K.P.; Ashraf, W.; Cao, Y. Properties of recycled concrete aggregate and their influence in new concrete production. Resour. Conserv. Recycl. 2018, 133, 30–49. [Google Scholar] [CrossRef]
  25. Uddin, M.T.; Mahmood, A.H.; Kamal, Md.R.I.; Yashin, S.M.; Zihan, Z.U.A. Effects of maximum size of brick aggregate on properties of concrete. Constr. Build. Mater. 2017, 134, 713–726. [Google Scholar] [CrossRef]
  26. Chen, H.-J.; Yen, T.; Chen, K.-H. Use of building rubbles as recycled aggregates. Cem. Concr. Res. 2003, 33, 125–132. [Google Scholar] [CrossRef]
  27. Nili, M.; Sasanipour, H.; Aslani, F. The Effect of Fine and Coarse Recycled Aggregates on Fresh and Mechanical Properties of Self-Compacting Concrete. Materials 2019, 12, 1120. [Google Scholar] [CrossRef] [PubMed]
  28. Desmyter, J.; Van Dessel, J.; Blockmans, S. The use of recycled concrete and masonry aggregates in concrete: Improving the quality and purity of the aggregates. In Exploiting Wastes in Concrete; Thomas Telford Publishing: London, UK, 1999; pp. 139–149. ISBN 978-0-7277-4724-2. [Google Scholar]
  29. Cavalline, T.L.; Weggel, D.C. Recycled brick masonry aggregate concrete: Use of brick masonry from construction and demolition waste as recycled aggregate in concrete. Struct. Surv. 2013, 31, 160–180. [Google Scholar] [CrossRef]
  30. Khatib, J.M. Properties of concrete incorporating fine recycled aggregate. Cem. Concr. Res. 2005, 35, 763–769. [Google Scholar] [CrossRef]
  31. Mirian, V.-L.M.; Isabel, M.-L.; Cristina, V.-H.; Pablo, V.-B. Empirical definition of effective water/cement ratio in mortars with recycled aggregate depending on the absorption. In Proceedings of the Congreso Internacional de Construcción Sostenible y Soluciones Ecoeficientes, Sevilla, Spain, 25–27 May 2015. [Google Scholar]
  32. Marshall, A.L. The thermal properties of concrete. Build. Sci. 1972, 7, 167–174. [Google Scholar] [CrossRef]
  33. Callejas, I.J.A.; Durante, L.C.; de Oliveira, A.S.; Callejas, I.J.A.; Durante, L.C.; Oliveira, A.S. de Thermal resistance and conductivity of recycled construction and demolition waste (RCDW) concrete blocks. REM Int. Eng. J. 2017, 70, 167–173. [Google Scholar] [CrossRef]
  34. Kim, K.-H.; Jeon, S.-E.; Kim, J.-K.; Yang, S. An experimental study on thermal conductivity of concrete. Cem. Concr. Res. 2003, 33, 363–371. [Google Scholar] [CrossRef]
  35. Demirboǧa, R. Influence of mineral admixtures on thermal conductivity and compressive strength of mortar. Energy Build. 2003, 35, 189–192. [Google Scholar] [CrossRef]
  36. Khan, M.I. Factors affecting the thermal properties of concrete and applicability of its prediction models. Build. Environ. 2002, 37, 607–614. [Google Scholar] [CrossRef]
  37. Schackow, A.; Effting, C.; Folgueras, M.V.; Güths, S.; Mendes, G.A. Mechanical and thermal properties of lightweight concretes with vermiculite and EPS using air-entraining agent. Constr. Build. Mater. 2014, 57, 190–197. [Google Scholar] [CrossRef]
  38. Chen, B.; Liu, N. A novel lightweight concrete-fabrication and its thermal and mechanical properties. Constr. Build. Mater. 2013, 44, 691–698. [Google Scholar] [CrossRef]
  39. Sayadi, A.A.; Tapia, J.V.; Neitzert, T.R.; Clifton, G.C. Effects of expanded polystyrene (EPS) particles on fire resistance, thermal conductivity and compressive strength of foamed concrete. Constr. Build. Mater. 2016, 112, 716–724. [Google Scholar] [CrossRef]
  40. Dissanayake, D.M.K.W.; Jayasinghe, C.; Jayasinghe, M.T.R. A comparative embodied energy analysis of a house with recycled expanded polystyrene (EPS) based foam concrete wall panels. Energy Build. 2017, 135, 85–94. [Google Scholar] [CrossRef]
  41. Wang, W.; Liu, Y.; Jiang, L.; Zhao, L.; Li, Z. Effect of physical properties of recycled coarse aggregate on the mechanical properties of recycled aggregate thermal insulation concrete (RATIC). Constr. Build. Mater. 2018, 180, 229–238. [Google Scholar] [CrossRef]
  42. Tang, W.C.; Lo, Y.; Nadeem, A. Mechanical and drying shrinkage properties of structural-graded polystyrene aggregate concrete. Cem. Concr. Compos. 2008, 30, 403–409. [Google Scholar] [CrossRef]
  43. Wang, W.; Zhao, L.; Liu, Y.; Li, Z. Mix design for recycled aggregate thermal insulation concrete with mineral admixtures. Mag. Concr. Res. 2014, 66, 492–504. [Google Scholar] [CrossRef]
  44. Kaya, A.; Kar, F. Properties of concrete containing waste expanded polystyrene and natural resin. Constr. Build. Mater. 2016, 105, 572–578. [Google Scholar] [CrossRef]
  45. Fernando, P.L.N.; Jayasinghe, M.T.R.; Jayasinghe, C. Structural feasibility of Expanded Polystyrene (EPS) based lightweight concrete sandwich wall panels. Constr. Build. Mater. 2017, 139, 45–51. [Google Scholar] [CrossRef]
  46. Xu, Y.; Jiang, L.; Xu, J.; Li, Y. Mechanical properties of expanded polystyrene lightweight aggregate concrete and brick. Constr. Build. Mater. 2012, 27, 32–38. [Google Scholar] [CrossRef]
  47. Šefflová, M.; Volf, M.; Pavlů, T. Thermal Properties of Concrete with Recycled Aggregate. Adv. Mater. Res. 2014, 1054, 227–233. [Google Scholar] [CrossRef]
  48. Leiva, C.; Solís-Guzmán, J.; Marrero, M.; García Arenas, C. Recycled blocks with improved sound and fire insulation containing construction and demolition waste. Waste Manag. 2013, 33, 663–671. [Google Scholar] [CrossRef] [PubMed]
  49. Šefflová, M.; Pavlů, T. Influence of Recycled Aggregate Quality on Recycled Concrete. Adv. Mater. Res. 2015, 1106, 45–48. [Google Scholar] [CrossRef]
  50. Meng, Y.; Ling, T.-C.; Mo, K.H. Recycling of wastes for value-added applications in concrete blocks: An overview. Resour. Conserv. Recycl. 2018, 138, 298–312. [Google Scholar] [CrossRef]
  51. Rao, A.; Jha, K.N.; Misra, S. Use of aggregates from recycled construction and demolition waste in concrete. Resour. Conserv. Recycl. 2007, 50, 71–81. [Google Scholar] [CrossRef]
  52. Sabai, M.M.; Cox, M.G.D.M.; Mato, R.R.; Egmond, E.L.C.; Lichtenberg, J.J.N. Concrete block production from construction and demolition waste in Tanzania. Resour. Conserv. Recycl. 2013, 72, 9–19. [Google Scholar] [CrossRef]
  53. Matos, A.M.; Sousa-Coutinho, J. Durability of mortar using waste glass powder as cement replacement. Constr. Build. Mater. 2012, 36, 205–215. [Google Scholar] [CrossRef]
  54. Matar, P.; Dalati, R.E. Strength of masonry blocks made with recycled concrete aggregates. Phys. Procedia 2011, 21, 180–186. [Google Scholar] [CrossRef]
  55. Zhan, B.J.; Xuan, D.X.; Poon, C.S.; Shi, C.J. Effect of curing parameters on CO 2 curing of concrete blocks containing recycled aggregates. Cem. Concr. Compos. 2016, 71, 122–130. [Google Scholar] [CrossRef]
  56. Xuan, D.; Zhan, B.; Poon, C.S. Assessment of mechanical properties of concrete incorporating carbonated recycled concrete aggregates. Cem. Concr. Compos. 2016, 65, 67–74. [Google Scholar] [CrossRef]
  57. Zhu, L.; Dai, J.; Bai, G.; Zhang, F. Study on thermal properties of recycled aggregate concrete and recycled concrete blocks. Constr. Build. Mater. 2015, 94, 620–628. [Google Scholar] [CrossRef]
  58. Juan-Valdés, A.; García-González, J.; Rodríguez-Robles, D.; Guerra-Romero, M.I.; López Gayarre, F.; De Belie, N.; Morán-del Pozo, J.M. Paving with Precast Concrete Made with Recycled Mixed Ceramic Aggregates: A Viable Technical Option for the Valorization of Construction and Demolition Wastes (CDW). Materials 2019, 12, 24. [Google Scholar] [CrossRef] [PubMed]
  59. Rodríguez, C.; Miñano, I.; Aguilar, M.Á.; Ortega, J.M.; Parra, C.; Sánchez, I. Properties of Concrete Paving Blocks and Hollow Tiles with Recycled Aggregate from Construction and Demolition Wastes. Materials 2017, 10, 1374. [Google Scholar] [CrossRef] [PubMed]
  60. Boehme, L.; Vrijders, J.; Van Gysel, A. Valorisation of Recycled Concrete Aggregates in Concrete C20/25 & C25/30. Concrete Structures Fir Sustainable Community: Stockholm, Sweden, 2012. [Google Scholar]
  61. Boehme, L. RecyMblock-application of recycled mixed aggregates in the manufacture of concrete construction blocks. In Proceedings of the SB11 HELSINKI World Sustainable Building Conference, Finnish Association of Civil Engineers RIL and VTT Technical Research Centre of Finland, Helsinki, Finland, 18–21 October 2011; pp. 2038–2047. [Google Scholar]
  62. Poon, C.S.; Chan, D. Paving blocks made with recycled concrete aggregate and crushed clay brick. Constr. Build. Mater. 2006, 20, 569–577. [Google Scholar] [CrossRef]
  63. Xiao, Z.; Ling, T.-C.; Kou, S.-C.; Wang, Q.; Poon, C.-S. Use of wastes derived from earthquakes for the production of concrete masonry partition wall blocks. Waste Manag. 2011, 31, 1859–1866. [Google Scholar] [CrossRef] [PubMed]
  64. Ganjian, E.; Jalull, G.; Sadeghi-Pouya, H. Using waste materials and by-products to produce concrete paving blocks. Constr. Build. Mater. 2015, 77, 270–275. [Google Scholar] [CrossRef]
  65. Xiao, Z.; Ling, T.-C.; Poon, C.-S.; Kou, S.-C.; Wang, Q.; Huang, R. Properties of partition wall blocks prepared with high percentages of recycled clay brick after exposure to elevated temperatures. Constr. Build. Mater. 2013, 49, 56–61. [Google Scholar] [CrossRef]
  66. Bonet-Martinez, E.; Perez-Villarejo, L.; Eliche-Quesada, D.; Castro, E. Manufacture of Sustainable Clay Bricks Using Waste from Secondary Aluminum Recycling as Raw Material. Materials 2018, 11, 2439. [Google Scholar] [CrossRef]
  67. Turgut, P.; Yahlizade, E.S. Research into Concrete Blocks with Waste Glass. Int. J. Civ. Environ. Eng. 2009, 3, 7. [Google Scholar]
  68. Chen, Z.; Li, J.S.; Poon, C.S. Combined use of sewage sludge ash and recycled glass cullet for the production of concrete blocks. J. Clean. Prod. 2018, 171, 1447–1459. [Google Scholar] [CrossRef]
  69. Lee, G.; Poon, C.S.; Wong, Y.L.; Ling, T.C. Effects of recycled fine glass aggregates on the properties of dry–mixed concrete blocks. Constr. Build. Mater. 2013, 38, 638–643. [Google Scholar] [CrossRef]
  70. Ling, T.-C.; Poon, C.-S. Use of recycled CRT funnel glass as fine aggregate in dry-mixed concrete paving blocks. J. Clean. Prod. 2014, 68, 209–215. [Google Scholar] [CrossRef]
  71. Sodupe-Ortega, E.; Fraile-Garcia, E.; Ferreiro-Cabello, J.; Sanz-Garcia, A. Evaluation of crumb rubber as aggregate for automated manufacturing of rubberized long hollow blocks and bricks. Constr. Build. Mater. 2016, 106, 305–316. [Google Scholar] [CrossRef]
  72. Mohammed, B.S.; Anwar Hossain, K.M.; Eng Swee, J.T.; Wong, G.; Abdullahi, M. Properties of crumb rubber hollow concrete block. J. Clean. Prod. 2012, 23, 57–67. [Google Scholar] [CrossRef]
  73. Ling, T.-C. Prediction of density and compressive strength for rubberized concrete blocks. Constr. Build. Mater. 2011, 25, 4303–4306. [Google Scholar] [CrossRef]
  74. Sadek, D.M.; El Nouhy, H.A. Properties of paving units incorporating crushed ceramic. HBRC Journal 2014, 10, 198–205. [Google Scholar] [CrossRef]
  75. Gencel, O.; Ozel, C.; Koksal, F.; Erdogmus, E.; Martínez-Barrera, G.; Brostow, W. Properties of concrete paving blocks made with waste marble. J. Clean. Prod. 2012, 21, 62–70. [Google Scholar] [CrossRef]
  76. Uygunoğlu, T.; Topcu, I.B.; Gencel, O.; Brostow, W. The effect of fly ash content and types of aggregates on the properties of pre-fabricated concrete interlocking blocks (PCIBs). Constr. Build. Mater. 2012, 30, 180–187. [Google Scholar] [CrossRef]
  77. Chowdhury, S.; Maniar, A.T.; Suganya, O. Polyethylene Terephthalate (PET) Waste as Building Solution. Int. J. Chem. Environ. Biol. Sci. 2013, 1, 5. [Google Scholar]
  78. Hossain, Md.U.; Xuan, D.; Poon, C.S. Sustainable management and utilisation of concrete slurry waste: A case study in Hong Kong. Waste Manag. 2017, 61, 397–404. [Google Scholar] [CrossRef] [PubMed]
  79. Kou, S.-C.; Zhan, B.-J.; Poon, C.-S. Properties of partition wall blocks prepared with fresh concrete wastes. Constr. Build. Mater. 2012, 36, 566–571. [Google Scholar] [CrossRef]
  80. de Brito, J.; Saikia, N. Recycled Aggregate in Concrete; Green Energy and Technology; London: London, UK, 2013; ISBN 978-1-4471-4539-4. [Google Scholar]
  81. Dhir, R.K.; de Brito, J.; Silva, R.V.; Lye, C.Q. 10-Recycled Aggregate Concrete: Durability Properties. In Sustainable Construction Materials; Dhir, R.K., de Brito, J., Silva, R.V., Lye, C.Q., Eds.; Woodhead Publishing Series in Civil and Structural Engineering; Woodhead Publishing: Sawston, UK, 2019; pp. 365–418. ISBN 978-0-08-100985-7. [Google Scholar]
  82. Pavlů, T.; Šefflová, M. Study of the Freeze-Thaw resistance of the fine-aggregate concrete. In Proceedings of the EAN 2016—54th International Conference on Experimental Stress Analysis, Srni, Czech Republic, 30 May–2 June 2016. [Google Scholar]
  83. Bravo, M.; de Brito, J.; Pontes, J.; Evangelista, L. Durability performance of concrete with recycled aggregates from construction and demolition waste plants. Constr. Build. Mater. 2015, 77, 357–369. [Google Scholar] [CrossRef]
  84. Neville, A.M. Properties of concrete, 5th ed.; Pearson: Harlow, UK; New York, NY, USA, 2011; ISBN 978-0-273-75580-7. [Google Scholar]
  85. Pavlů, T.; Šefflová, M. The Static and the Dynamic Modulus of Elasticity of Recycled Aggregate Concrete. Adv. Mater. Res. 2014, 1054, 221–226. [Google Scholar] [CrossRef]
  86. Silva, R.V.; de Brito, J.; Dhir, R.K. Establishing a relationship between modulus of elasticity and compressive strength of recycled aggregate concrete. J. Clean. Prod. 2016, 112, 2171–2186. [Google Scholar] [CrossRef]
  87. Dhir, R.K.; de Brito, J.; Silva, R.V.; Lye, C.Q. 9-Deformation of Concrete Containing Recycled Concrete Aggregate. In Sustainable Construction Materials; Dhir, R.K., de Brito, J., Silva, R.V., Lye, C.Q., Eds.; Woodhead Publishing Series in Civil and Structural Engineering; Woodhead Publishing: Sawston, UK, 2019; pp. 283–363. ISBN 978-0-08-100985-7. [Google Scholar]
  88. Ling, T.C.; Nor, H.M.; Lim, S.K. Using recycled waste tyres in concrete paving blocks. Proc. Inst. Civ. Eng. Waste Resour. Manag. 2010, 163, 37–45. [Google Scholar] [CrossRef]
Figure 1. Recycled masonry aggregate. (a) RMA of fraction 4/8 mm; (b) RMA of fraction 8/16 mm
Figure 1. Recycled masonry aggregate. (a) RMA of fraction 4/8 mm; (b) RMA of fraction 8/16 mm
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Figure 2. Sieving curves for natural aggregate, recycled masonry aggregate, and recycle expanded polystyrene used in concrete mixtures. (a) fraction 0–4 mm (b) fraction 4–8 and 0–8 mm (c) fraction 8–16 mm.
Figure 2. Sieving curves for natural aggregate, recycled masonry aggregate, and recycle expanded polystyrene used in concrete mixtures. (a) fraction 0–4 mm (b) fraction 4–8 and 0–8 mm (c) fraction 8–16 mm.
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Figure 3. Types of recycled masonry aggregate concrete – tested samples.
Figure 3. Types of recycled masonry aggregate concrete – tested samples.
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Figure 4. Comparison of water absorption by immersion of recycled aggregate concrete with RMA and EPS with conventional concrete.
Figure 4. Comparison of water absorption by immersion of recycled aggregate concrete with RMA and EPS with conventional concrete.
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Figure 5. Comparison and progression of capillary water absorption of recycled aggregate concrete with RMA and EPS with conventional concrete.
Figure 5. Comparison and progression of capillary water absorption of recycled aggregate concrete with RMA and EPS with conventional concrete.
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Figure 6. Comparison of compressive strength of recycled aggregate concrete with RMA and EPS with conventional concrete.
Figure 6. Comparison of compressive strength of recycled aggregate concrete with RMA and EPS with conventional concrete.
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Figure 7. Comparison of thermal conductivity of recycled aggregate concrete with RMA and EPS with conventional concrete.
Figure 7. Comparison of thermal conductivity of recycled aggregate concrete with RMA and EPS with conventional concrete.
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Figure 8. Effect of dry density on thermal conductivity for all tested concrete mixtures.
Figure 8. Effect of dry density on thermal conductivity for all tested concrete mixtures.
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Figure 9. Effect of compressive strength on thermal conductivity for all tested concrete mixtures.
Figure 9. Effect of compressive strength on thermal conductivity for all tested concrete mixtures.
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Figure 10. Effect of replacement rate on thermal conductivity and dry density.
Figure 10. Effect of replacement rate on thermal conductivity and dry density.
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Table 1. Thermal properties of various materials in the dry state [33,36,37,47,48,49].
Table 1. Thermal properties of various materials in the dry state [33,36,37,47,48,49].
Type of AggregateThermal Conductivity—λType of ConcreteThermal Conductivity—λCompressive Strength Density
Aggregate(W/(m·K))Concrete(W/(m·K))(MPa)(kg/m3)
NA-Basalt4.03Basalt concrete2.26N/AN/A
NA-Limestone3.15Limestone concrete2.03N/AN/A
NA-Siltstone3.52Siltstone concrete2.21N/AN/A
NA-Quartzite8.58Quartzite concrete2.77N/AN/A
RA-Concrete2.22RCAC 50%0.9034.72050
RCAC 70%0.8039.12040
RA-Masonry0.8RMAC-various replacement0.60–0.784.01480
RA-EPS 0.04Concrete EPS content 55%0.5611.851140
Concrete EPS content 65%0.507.741070
RCAC: Recycled concrete aggregate concrete; RMAC: Recycled masonry aggregate concrete.
Table 2. Physical properties of particular fractions of used aggregates.
Table 2. Physical properties of particular fractions of used aggregates.
Types of Recycled AggregateGrading (mm)Oven-Dried Particle Density (kg/m3)Water Absorption Capacity (%)
Natural aggregate0–425702
4–825301.7
8–1625401.9
Recycled masonry aggregate 10–4220016
4–8197013.8
8–16195011.9
Recycled masonry aggregate 20–8186014.7
8–16216012.1
Recycled EPS0–430-
Table 3. Composition of recycled masonry aggregates A and B.
Table 3. Composition of recycled masonry aggregates A and B.
MaterialClassRMA 1RMA 2
4–8 mm8–16 mm4–8 mm8–16 mm
Concrete (%)Rc12.5%30.9%27%25%
Unbound aggregates (%)Ru16.5%13.7%12%29%
Ceramics (%)Rb67.9%48.9%61.0%47.0%
Asphalt (%)Ra2.8%2.8%0%0%
Lightweight particles (%)FL0.3%0.0%0%0%
Natural soil and others (%)X0.0%0.7%27%25%
Glass (%)Rg0.0%2.9%12%29%
Table 4. Concrete mix proportion, per cubic meter.
Table 4. Concrete mix proportion, per cubic meter.
DesignationNACRMAC ARMAC BRMAC CRMAC DRMAC ERMAC EPS A RMAC EPS BRMAC EPS CRMAC EPS D
Replacement ratio of aggregate (%)06675981009576769883
Amount of EPS (kg)0000006446
Cement (kg)320320320320320320320320320320
Water (kg)160256215240184285181195208230
Sand (kg)6816854553500440446217220
NCA 4/8 (kg)54100009600088
NCA 8/16 (kg)616000000000
RFA 0/4 (kg)0004595290002500
RCA 0/8 (kg)000001267000712
RCA 4/8 (kg)04555693981880862811870
RCA 8/16 (kg)071949353477205625355570
w/c eff (–)0.500.500.500.500.500.500.500.500.500.50
w/c (–)0.500.810.680.750.580.890.560.600.650.72
Table 5. Composition of concrete mixtures.
Table 5. Composition of concrete mixtures.
RMAC MixturesType of RMACoarse Fraction Repl.Fine Fraction Repl.EPS
RMAC ARMA1100%0%0%
RMAC BRMA 1100%35%0%
RMAC CRMA 1100%95%0%
RMAC DRMA 2100%100%0%
RMAC ERMA 295%0%
RMAC EPS ARMA 2100%10%30%
RMAC EPS BRMA 1100%25%18%
RMAC EPS CRMA 1100%65%18%
RMAC EPS DRMA 285%30%
Table 6. Average values of results of physical properties of concrete, including standard deviation.
Table 6. Average values of results of physical properties of concrete, including standard deviation.
Recycled Concrete MixtureDensityWater Absorption by ImmersionCapillary Water Absorption
Designation(kg/m3)σ(%)σ(kg/m2)
0NAC23059.136.352.814.87
1RMAC A20284.1810.270.124.75
2RMAC B201711.8713.090.363.33
3RMAC C190810.9813.870.266.31
4RMAC D19394.6714.410.0810.41
5RMAC E18849.2915.030.0212.75
6RMAC EPS A15618.0912.070.422.23
7RMAC EPS B177512.8511.620.213.79
8RMAC EPS C17026.9112.920.204.53
9RMAC EPS D16759.0614.560.509.49
Table 7. Average values of results of mechanical properties of concrete, including standard deviation.
Table 7. Average values of results of mechanical properties of concrete, including standard deviation.
Recycled Concrete MixtureCompressive StrengthFlexural StrengthStatic Modulus of Elasticity
Designation(MPa)σ(MPa)σ(GPa)σ
0NAC47.990.966.4434.70.7134.7
1RMAC A29.430.364.8619.90.6019.9
2RMAC B33.771.205.8120.00.5120.0
3RMAC C29.030.604.6115.70.2415.7
4RMAC D33.260.296.5314.00.0714.0
5RMAC E30.060.557.2914.90.2214.9
6RMAC EPS A12.650.333.2211.00.1711.0
7RMAC EPS B20.320.513.9514.40.2914.4
8RMAC EPS C18.260.433.2612.40.7012.4
9RMAC EPS D19.490.424.1712.50.0012.5
Table 8. Average values of results of thermal properties of concrete, including standard deviation.
Table 8. Average values of results of thermal properties of concrete, including standard deviation.
Recycled Concrete MixtureThermal Conductivity—λVolume Heat Capacity—cρThermal Diffusivity—a
Designation(W/(m·K))σ*106 (J/(m3·K))σ*10−6 (m2/s)σ
0NAC2.7780.151.7730.151.5730.09
1RMAC A1.2070.121.7900.020.6760.07
2RMAC B0.9650.001.6910.040.5710.01
3RMAC C0.8790.061.6540.010.5310.04
4RMAC D0.9080.041.6660.050.5450.02
5RMAC E0.9110.051.6260.030.5610.03
6RMAC EPS A0.8750.021.7280.010.5060.02
7RMAC EPS B0.9250.021.7920.030.5160.01
8RMAC EPS C0.7840.051.6620.050.4730.04
9RMAC EPS D0.8300.041.6170.050.5130.02
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