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Updated: Sep 29, 2025
11:14
Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent
Published on: February 21, 2017
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Experimental Study on Subgrade Material of Calcium Silicate Slag
De Zhang1,2, Zhijie Yang1,2, Dong Kang1,2
1School of Mining and Technology, Inner Mongolia University of Technology, Hohhot 010051, China.
Materials (Basel, Switzerland)
|March 25, 2022
Summary
Calcium silicate slag (CSS) enhances pavement base materials by replacing fly ash (FA). This innovative use of industrial waste improves unconfined compressive strength (UCS) and meets road construction standards, demonstrating feasibility.
Area of Science:
- Materials Science
- Civil Engineering
- Waste Management
Background:
- Calcium silicate slag (CSS) is a byproduct of aluminum extraction from fly ash.
- Resource utilization of CSS is a significant environmental and economic challenge.
- Fly ash (FA) is commonly used in road base construction.
Purpose of the Study:
- To investigate the feasibility of using CSS as a partial replacement for FA in inorganic binder stabilized road base materials.
- To evaluate the impact of CSS content on the mechanical properties, microstructure, and durability of pavement base materials.
- To assess the practical application of CSS-based pavement base materials in a pilot test.
Main Methods:
- Preparation of pavement base materials with varying CSS replacement ratios of FA.
- Testing of unconfined compressive strength (UCS) at different curing ages (7 and 28 days).
- Analysis of phase composition, microstructure, and durability (freeze-thaw resistance, water stability).
Main Results:
- Increasing CSS content led to a significant increase in UCS, with improvements of 7.90%–28.95% after 28 days.
- Hydration products (C-A-S-H and C-S-H gels) and silica polymerization increased with CSS content, densifying the structure.
- Pilot tests confirmed that CSS pavement base materials meet Chinese road construction standards for UCS, freeze-thaw resistance, and water stability.
Conclusions:
- CSS can effectively replace a portion of FA in road base materials, enhancing mechanical strength and durability.
- The improved performance is attributed to the formation of beneficial hydration products and structural densification.
- The successful pilot application demonstrates the practical feasibility and potential of CSS in sustainable road construction.
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