Experimental Study of the Principal Characteristics of Sustainable Micropile Grout Containing Alternative Sands

https://doi.org/10.28991/CEJ-2024-010-10-019
Alternative Sands Crushed Stones Micropile Grout Strength Microstructure of Grout.

Authors

  • Dao Phuc Lam Faculty of Civil Engineering, University of Transport Technology, Hanoi,, Viet Nam
  • Nguyen Van Manh 2) Faculty of Civil Engineering, Hanoi University of Mining and Geology, Hanoi, Vietnam. 3) Geotechnical Engineering, Construction Materials and Sustainability Research Group, Hanoi University of Mining and Geology, Hanoi, Vietnam.
  • Pham Thi Nhan 2) Faculty of Civil Engineering, Hanoi University of Mining and Geology, Hanoi, Vietnam. 3) Geotechnical Engineering, Construction Materials and Sustainability Research Group, Hanoi University of Mining and Geology, Hanoi, Vietnam.
  • Le Huy Viet 2) Faculty of Civil Engineering, Hanoi University of Mining and Geology, Hanoi, Vietnam. 3) Geotechnical Engineering, Construction Materials and Sustainability Research Group, Hanoi University of Mining and Geology, Hanoi, Vietnam.
  • Tang Van Lam 2) Faculty of Civil Engineering, Hanoi University of Mining and Geology, Hanoi, Vietnam. 3) Geotechnical Engineering, Construction Materials and Sustainability Research Group, Hanoi University of Mining and Geology, Hanoi, Vietnam.
  • Dang Van Phi 2) Faculty of Civil Engineering, Hanoi University of Mining and Geology, Hanoi, Vietnam. 3) Geotechnical Engineering, Construction Materials and Sustainability Research Group, Hanoi University of Mining and Geology, Hanoi, Vietnam.
  • Ngo Xuan Hung 2) Faculty of Civil Engineering, Hanoi University of Mining and Geology, Hanoi, Vietnam. 3) Geotechnical Engineering, Construction Materials and Sustainability Research Group, Hanoi University of Mining and Geology, Hanoi, Vietnam.
  • Piotr Osinski 3) Geotechnical Engineering, Construction Materials and Sustainability Research Group, Hanoi University of Mining and Geology, Hanoi, Vietnam. 4) Institute of Civil Engineering, Warsaw University of Life Sciences, 02-787 Warsaw, Poland.
  • Kennedy C. Onyelowe 3) Geotechnical Engineering, Construction Materials and Sustainability Research Group, Hanoi University of Mining and Geology, Hanoi, Vietnam. 5) Department of Civil Engineering, Michael Okpara University of Agriculture, Umudike, Nigeria.
  • Bui Van Duc
    buivanduc@humg.edu.vn
    2) Faculty of Civil Engineering, Hanoi University of Mining and Geology, Hanoi, Vietnam. 3) Geotechnical Engineering, Construction Materials and Sustainability Research Group, Hanoi University of Mining and Geology, Hanoi, Vietnam.
Vol. 10 No. 10 (2024): October
Research Articles

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The paper discloses a laboratory investigation on employing manufactured sand cement as grout in micropiling works. In practice, to prepare micropile grouts, Portland cement is commonly used. The grout usually consists of natural sand to obtain the strength parameters and value international standards require for micropile construction. It is common knowledge that using concrete and natural sand leaves its environmental footprint. Although there have been numerous attempts to use more environmentally friendly materials, utilizing manufactured sands, particularly for micropile grouting, is a scientific challenge that researchers are still trying to address. The present study investigates the performance of micropile grout mixtures containing manufactured (M) sands, including limestone (L-M) and granite (G-M) rock as replacements for natural sand. For this purpose, laboratory tests, including unconfined compression strength (UCS) and workability tests, were conducted on samples with varying compositions and ratios of L-M and G-M materials. The complementary microstructure and chemical composition analyses were performed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analysis. The laboratory results indicate that the UCS at 28 days of hardening for all M-sand cement mixtures exceeds the minimum standards required values, falling in a range of 40-50.2 MPa. It's noteworthy that the strength of cement grout containing L-M sand was found to be higher than that of G-M sand. The SEM results show the G-M sand grain is rougher than L-M, and the L-M sand grain size is finer than the G-M samples, which causes a decrease in porosity at the interfacial transition zone. Grout workability tests demonstrated that higher water-cement ratios (W/C) led to increased fluidity across all mixtures, with G-M sand resulting in lower flowability than L-M samples. Overall, the results suggest that the proposed mixtures could serve as sustainable alternatives for micropiling, reducing cement content and utilizing alternative, reused materials in grouting mixtures more effectively and sustainably.

 

Doi: 10.28991/CEJ-2024-010-10-019

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