Experimental Study of Compressive Strength of Geopolymer Concrete Based on XRF and SEM Analysis
Subject Areas : Analysis of Structure and Earthquake
Mohammadhossein Mansourghanaei
1
,
Morteza Biklaryan
2
,
Alireza Mardookhpour
3
1 - گروه مهندسی عمران، واحد چالوس، دانشگاه آزاد اسلامی، چالوس، ایران.
2 - Department of Civil Engineering, Chalous Branch, Islamic Azad University, Chalous, Iran
3 - department of civil engineering islamic azad university lahijan branch iran
Keywords: Scanning electron microscopy (SEM), Geopolymer concrete, mechanical properties of concrete, Compressive strength test, X-ray fluorescence (XRF),
Abstract :
In this research, three mixing designs were made of geopolymer concrete containing 92, 96 and 100% composite blast-furnace slag including 8, 4 and 0% nanosilica, respectively. After performing the compressive strength test and selecting one of these three designs as the optimal design in terms of superior mechanical properties, by adding 1 and 2% of polyolefin fibers to the optimal design, two more designs were made of geopolymer concrete. Concrete specimens were subjected to compressive strength tests (at 7, 28 and 90 days of curing), XRF (at 7 days of curing), and SEM (at 90 days of curing). The results were evaluated and compared with the results of a mixing design made of ordinary concrete containing Portland cement. The results of the analyses in this research exhibited the superiority in mechanical and microstructural properties of the geopolymer concrete in comparison with the ordinary concrete at all ages. At the 90-day curing age, as the best age in terms of performance, the minimum (62.43 MPa) and maximum (82.96 MPa) compressive strength values were obtained in designs 1 and 4, respectively. At this age, adding up to 8% nanosilica in geopolymer concrete enhanced the compressive strength up to 21.94% and adding up to 2% of fibers reduced the compressive strength up to 22.49% in this type of concrete. The results of XRF and SEM analyses overlapped with each other and were in accordance with the results of the compressive strength test.
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