- Open Access
Evaluation on the Mechanical Performance of Low-Quality Recycled Aggregate Through Interface Enhancement Between Cement Matrix and Coarse Aggregate by Surface Modification Technology
© The Author(s) 2016
Received: 1 September 2015
Accepted: 20 December 2015
Published: 20 January 2016
In this study, a quantitative review was performed on the mechanical performance, permeation resistance of concrete, and durability of surface-modified coarse aggregates (SMCA) produced using low-quality recycled coarse aggregates, the surface of which was modified using a fine inorganic powder. The shear bond strength was first measured experimentally and the interface between the SMCA and the cement matrix was observed with field-emission scanning electron microscopy. The results showed that a reinforcement of the interfacial transition zone (ITZ), a weak part of the concrete, by coating the surface of the original coarse aggregate with surface-modification material, can help suppress the occurrence of microcracks and improve the mechanical performance of the aggregate. Also, the use of low-quality recycled coarse aggregates, the surfaces of which were modified using inorganic materials, resulted in improved strength, permeability, and durability of concrete. These results are thought to be due to the enhanced adhesion between the recycled coarse aggregates and the cement matrix, which resulted from the improved ITZ in the interface between a coarse aggregate and the cement matrix.
In this study, crushed-stone coarse aggregates, whose surfaces had been modified, were used to fabricate the concrete specimens. The bonding performance was assessed and the interface was observed with microscopy. The resulting improvement in the concrete’s mechanical performance and the applicability of the surface-modification technology to low-quality recycled aggregates with low density and large water absorption ratio was determined. Moreover, the effects of surface modification on low-quality recycled aggregates, which are mainly used as a sub-base course material, were examined, and their effects on the mechanical and permeation resistance of the water and deterioration factor into the concrete and durability performance of concrete were reviewed.
2 Surface-Modification Technology
3 Effects of Surface Modification on the Mechanical Characteristics of Each Interface
3.1 Overview of the Experiment
3.2 Experimental Method
Composition of SMCP.
C × 100
Composition of mortar.
Unit weight (kg/m3)
4.5 ± 1.5
Experimental factors and conditions.
Cutting specimen of crushed hard sandstone (standard density: 2.66 g/cm3; water absorption ratio: 0.70 %)
Normal strength, W/C = 55 %
30°, 45°, 60°
3.3 Compressive- and Tensile-Shear Bond
3.4 Microscopic Observation of the Interface Between Each Aggregate and the Cement Matrix
4 Effects of Surface Modification on the Mechanical Characteristics of Low-Quality Recycled Aggregates
In Sect. 3, the results of examining the bonding performance of the simulated concrete fabricated by performing surface modification on crushed stone coarse aggregate and observing the specimens microscopically showed that it was possible to improve the mechanical performance (improvement of ITZ) of concrete through surface modification. Also, based on the results, it is deemed possible to enhance the mechanical performance of concrete and improve the interface enhancement between cement matrix and low-quality recycled coarse aggregate (LRCA) through surface modification (Xiao 2013). Thus, in this section, an experiment was conducted, according to Japanese Industrial Standards (JIS), for the purpose of reviewing the permeability and durability performance (drying shrinkage, neutralization, freezing-thawing) and mechanical performance of concrete by examining the effect of surface modification on improving the adhesion quality of recycled aggregate.
Type and quality of coarse aggregates.
Standard density (g/cm3)
Water absorption ratio (%)
Composition of modification paste (based on 1 kg of original coarse aggregates) (Choi et al. 2014a).
Table flow (mm)
C × 100
C × 1.9 (b*)
4.2 Composition of Concrete
Composition of concrete.
Unit weight (kg/m3)
180 ± 25
4.5 ± 1.5
C × 0.5(a*)
C × 0.5(a*)
Slump and air content of each type of concrete.
Air content (%)
4.3 Results and Discussion
4.3.1 Mechanical Characteristics
The modification treatment of the surface of adhesive paste consist of a porous causes densification on the surface of recycled coarse aggregates, resulting in higher density and lower absorption ratio compared to low-quality recycled aggregates as shown in Sect. 4.1. On the other hand, large amounts of adhesive paste are present in the low-quality recycled coarse aggregates (Fig. 10) and modified aggregates used in this study, and due to the large sizes of internal pores compared to general coarse aggregates, there may be an increased possibility of penetration of water and harmful substances into the concrete from the external environment. In other words, the progressive penetration of deterioration factors such as water, CO2 gas and chloride ions (Cl−) into the concrete increases permeability, which is highly associated with durability. This in turn accelerates deterioration of concrete and as a consequence, there are concerns of fatal damage to the concrete structure concerned (Jacobsen 1996; Wang et al. 1997; Khatri and Sirivivatnanon 1997). Accordingly, after fabricating concrete using low-quality recycled coarse aggregates and modified coarse aggregates, the water and air permeability coefficients of each specimen were measured and the correlations between the water and air permeability coefficients and compressive strength were analyzed as a means to determine the water tightness and air tightness of each concrete specimen.
5 Results and Discussion
When the W/C ratio was 55 %, the improvements in the shear bond strength were confirmed to be due to the SMCP coating, and the ITZ was densified by the admixtures (inorganic materials). The FE-SEM results confirmed that the interface between the SMCA and the cement matrix was denser and ITZ was strengthened with a high level of calcium–silicate–hydrate by the surface modification.
The use of low-quality recycled coarse aggregates (LRCA), the surfaces of which were modified with inorganic materials, resulted in improved strength, permeability, and durability of concrete. These improvements are thought to be due to the enhanced adhesion between recycled coarse aggregate and cement matrices resulting from the improved ITZ that existed in the interface between the coarse aggregate and the cement matrix.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
- Choi, H. S., Kitagaki, R., & Noguchi, T. (2012). A study on the completely recovery of surface modification aggregate using microwave and effective utilization. In Proceedings of the 5th ACF international conference, Pattaya, Thailand, October 2012, Session 1–2, ACF2012-0093 (pp. 41–46).Google Scholar
- Choi, H. S., Kitagaki, R., & Noguchi, T. (2014a). Effective recycling of surface modification aggregate using microwave heating. Journal of Advanced Concrete Technology, 12, 34–45.View ArticleGoogle Scholar
- Choi, H. S., Kitagaki, R., & Noguchi, T. (2014b). Using microwave heating to completely recycle concrete. Journal of Environmental Protection, 5, 583–596.View ArticleGoogle Scholar
- Hendriks, C. H. F., & Janssen, G. M. T. (2001). Construction and demolition waste—General process. HERON, 46, 79–88.Google Scholar
- Hilsdorf, H. K., & Kropp, J. (1995). Performance criteria for durability, RILEM Report 12, London, UK, pp. 166–178.Google Scholar
- Jacobsen, S. (1996). Effect of cracking and healing on chloride transport in OPC concrete. Cement and Concrete Research, 26(6), 869–881.View ArticleGoogle Scholar
- Khatri, R. P., & Sirivivatnanon, V. (1997). Role of permeability in sulfate attack. Cement and Concrete Research, 27(8), 1179–1189.View ArticleGoogle Scholar
- Kumar Mehta, P., & Moneiro, P. J. M. (2006). Concrete—Microstructure, Properties and Materials. New York, NY: McGraw-Hill Companies.Google Scholar
- Nagataki, S., Gokce, A., & Saeki, T. (2000). Effects of recycled aggregate characteristics on performance parameters of recycled aggregate concrete. American Concrete Institute, ACI Special Publication, 52, 462–467.Google Scholar
- Noguchi, T. (2008). Resource recycling in concrete: Present and future. Stock Management for Sustainable Urban Regeneration, 4, 255–274.View ArticleGoogle Scholar
- Noguchi, T., & Tamura, M. (2001). Concrete design towards complete recycling. Structural Concrete Journal of the fib, 2, 155–167.View ArticleGoogle Scholar
- Shima, H., Tateyashiki, H., Matsuhashi, R., & Yoshida, Y. (2005). An advanced concrete recycling technology and its applicability assessment through input-output analysis. Journal of Advanced Concrete Technology, 3, 53–67.View ArticleGoogle Scholar
- Tazawa, E. (2002). Concrete engineering (p. 127). Tokyo, Japan: Asakura Publication.Google Scholar
- Tsujino, M., Noguchi, T., Tamura, M., Kanematsu, M., & Maruyama, I. (2007). Application of conventionally recycled coarse aggregate to concrete structure by surface modification treatment. Journal of Advanced Concrete Technology, 5, 13–25. doi:10.3151/jact.5.13.View ArticleGoogle Scholar
- Tsujino, M., Noguchi, T., Kitagaki, R., & Nagai, H. (2010). Completely recyclable concrete of aggregate-recovery type by a new technique using aggregate coating. Architectural Institute of Japan, 75(647), 17–24. (in Japanese).Google Scholar
- Tsujino, M., Noguchi, T., Kitagaki, R., & Nagai, H. (2011). Completely recyclable concrete of aggregate-recovery type by using microwave heating. Architectural Institute of Japan, 76(660), 223–229. (in Japanese).Google Scholar
- Um, T. S., & Choi, S. H. (1997). The effect of the mineralogical features of aggregates in the bonding force and workability of the concrete. Journal of the Korea Concrete Institute, 9(5), 207–216. (in Korean).Google Scholar
- Wang, K., Jansen, D. C., & Shah, S. P. (1997). Permeability study of cracked concrete. Cement and Concrete Research, 27(3), 381–393.View ArticleGoogle Scholar
- Xiao, J. (2013). Properties of interfacial transition zones in recycled aggregate concrete tested by nanoindentation. Cement and Concrete Research, 37(3), 276–292.View ArticleGoogle Scholar