Investigating the Effects of Using Microsilica and Nanosilica on the Hardened Mechanical Properties and Durability of SCC Containing Recycled Aggregates
Subject Areas : Analysis of Structure and Earthquake
Reza Farokhzad
1
(
Department of Civil Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran
)
mohsen mehrpoya
2
(
)
Keywords: Mechanical Properties, durability, silica fume, self-compacting concrete, Nano-silica, Recycled aggregate concrete,
Abstract :
Today, the wastes remaining from concrete degradation is considered as an environmental problem and is one of the biggest challenges in the building industry. Accordingly, many researchers have decided to re-use the materials of aggregates from degradation in concrete production cycles. In this paper, attempts were made to assess and if possible to promote the mechanical and durability characteristics after the addition of nano-silica and micro-silica to self-compacting concrete containing recycled aggregates (obtained from worn concrete degradation). One of the points to be considered in this paper was the attempt to use tests such as half-pole testing and concrete wave velocity. In this regard, 72 mixture designs were studied in 8 collections. In these mixture designs, with respect to the content of recycled aggregates, the nano- and micro-contents were changed. Then, the samples underwent mechanical tests including compressive strength and tensile strength, and durability tests including corrosion potential, concrete wave velocity (ultrasonic) and electrical strength. After the tests, with an increase in the use of nano-silica and micro-silica, the efficiency and fluidity of the fresh concrete were reduced, and compressive strength and tensile strength were increased. Also, at fixed strength, nano-silica caused less efficiency and fluidity than micro-silica and also, with an increase in the content of recycled aggregates in concrete, efficiency and fluidity as well as compressive strength and tensile strength of concrete were reduced.
1 - Medina C, Zhu W, Howind T, de Rojas MIS, Frías M. Influence of mixed recycled aggregate on the physical–mechanical properties of recycled concrete. Journal of cleaner production. 2014;68:216-25.
2- Ismail S, Ramli M. Mechanical strength and drying shrinkage properties of concrete containing treated coarse recycled concrete aggregates. Construction and Building Materials. 2014;68:726-39.
3- Farokhzad R, Mahdikhani M, Bagheri A, Baghdadi J. Representing a logical grading zone for self-consolidating concrete. Construction and Building Materials. 2016;115:735-45.
4- Jelokhani Niaraki R, Farokhzad R. Prediction of mechanical and fresh properties of self-consolidating concrete (SCC) using multi-objective genetic algorithm (MOGA). Journal of Structural Engineering and Geo-Techniques. 2017;7(2).
5- Hosseini P, Booshehrian A, Delkash M, Ghavami S, Zanjani M. Use of nano-SiO 2 to improve microstructure and compressive strength of recycled aggregate concretes. Nanotechnology in Construction 3. 2009:215-21.
6- Li W, Xiao J, Sun Z, Kawashima S, Shah SP. Interfacial transition zones in recycled aggregate concrete with different mixing approaches. Construction and Building Materials. 2012;35:1045-55.
7- Farokhzad R, Yaseri S, Entezarian MH, Yavari A. Investigating Effects of Sulfates on Compressive Strength of Different Types of Pozzolan Concrete and Measuring Penetration Rate by Ultrasound Tests at Different Ages.
8- Kwan WH, Ramli M, Kam KJ, Sulieman MZ. Influence of the amount of recycled coarse aggregate in concrete design and durability properties. Construction and Building Materials. 2012;26(1):565-73.
9- Mangialardi T, Paolini A. Workability of superplasticized microsilica-portland cement concretes. Cement and Concrete Research. 1988;18(3):351-62.
10- Otsuki N, Miyazato S-i, Yodsudjai W. Influence of recycled aggregate on interfacial transition zone, strength, chloride penetration and carbonation of concrete. Journal of materials in civil engineering. 2003;15(5):443-51.
11- Çakır Ö. Experimental analysis of properties of recycled coarse aggregate (RCA) concrete with mineral additives. Construction and Building Materials. 2014;68:17-25.
12- ASTMC33. Standard Specification for Concrete Aggregates. 2010.
13- ACI555. Concrete with Recycled Materials. 2002.
14- Bagheri A, Farrokhi F, Mahdikhani M, Farokhzad R, Baghdadi J. Representing Appropriate Aggregatess Grading Zone For Self-Consolidating Concrete by Using Soil Classifying Parameters.
16- Yaseri S, Hajiaghaei G, Mohammadi F, Mahdikhani M, Farokhzad R. The role of synthesis parameters on the workability, setting and strength properties of binary binder based geopolymer paste. Construction and Building Materials. 2017;157:534-45.
16- EFNARC S. Guidelines for self-compacting concrete. EFNARC,UK (www efnarc org). 2005.
17- قدوسی, جاوید ش, چراتی ر. بررسی تنش جاری شدن و ویسکوزیته پلاستیک مخلوطهای بتن خود تراکم حاوی پودر سنگ با استفاده از دستگاه رئومتر بتن ساخته شده برای اولین بار در ایران. مهندسی عمران مدرس. 2015;14(3):107-15.
18- B.S.1881-116. Testing concrete. Method for determination of compressive strength of concrete cubes 1988.
19- ASTMC496. Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens. 2011.
20- ASTMC876-15. Standard Test Method for Corrosion Potentials of Uncoated Reinforcing Steel in Concrete. 2015.
21- ASTMC597-16. Standard Test Method for Pulse Velocity Through Concrete. 2016.
22- Sturrup V, Vecchio F, Caratin H. Pulse velocity as a measure of concrete compressive strength. Special Publication. 1984;82:201-28.
23- Neville AM. Properties of concrete: Longman London; 1995.
24- Neville AM, Brooks JJ. Concrete technology1987.
25- McCarter WJ, Starrs G, Kandasami S, Jones R, Chrisp M. Electrode configurations for resistivity measurements on concrete. ACI materials journal. 2009;106(3):258-64.
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