Effect of Water–Solid Ratio on the Performance, Microstructure Evolution, and Low-Carbon Characteristics of Multi-Solid-Waste-Based Flowable Stabilized Soil

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Quantitative data on strength, microstructure, and LCA provide a benchmark for further optimization of waste-based geopolymers.

🏢実務担当者:Offers a ready-to-use formulation with verified performance and environmental benefits for soil stabilization in construction.

🏛政策担当者:Supports policies promoting industrial waste utilization and low-carbon building materials with clear emission reduction metrics.

To promote the high-value utilization of industrial solid wastes and address the disposal of excavated soils, a novel low-carbon composite cementitious material, solid waste-based geopolymer cement (SGPC), was developed, consisting of soda residue (SR), granulated blast furnace slag (GGBS), phosphogypsum (PG), and ordinary Portland cement (PC) in a mass ratio of 10:81:9:25, with industrial solid wastes accounting for 80% of the binder. The effects of water-to-solid ratio (W/S = 0.41–0.49) on the workability, mechanical performance, and microstructural evolution of SGPC-stabilized soil were systematically investigated to provide a sustainable alternative to conventional cement-based stabilizers. The results indicate that the optimum water-to-solid ratio is 0.43 (SGPC43), with a 28-day unconfined compressive strength of 1450 kPa, exceeding the engineering requirement of 0.8 MPa and reaching over 85% of that of a pure cement system (C43). The flowability remained 163 mm after 60 min, with initial and final setting times of 43 h and 58 h, respectively. Microstructural analysis revealed that the alkalinity provided by soda residue promotes the hydration of slag and phosphogypsum, forming interwoven calcium (alumino) silicate hydrate (C–(A)–S–H) and ettringite (AFt), which fill pores and form a dense structure, thereby enhancing mechanical performance. Environmental and economic assessments show that the CO2 emission of SGPC43 per ton of binder decreases from 930 kg CO2-e/t to 235 kg CO2-e/t (approximately 74.7% reduction), while the material cost decreases from 110 USD/t to 53 USD/t (approximately 51.8% reduction). A simplified uncertainty analysis indicates that the carbon reduction remains at 70% ± 5% and the cost reduction at 50% ± 5%, confirming the robustness of the results. Overall, SGPC43 demonstrates excellent engineering performance, environmental benefits, and economic feasibility, highlighting its potential as a low-carbon and sustainable stabilizing material.

• openalex https://doi.org/10.3390/ma19112247first seen 2026-05-28 05:04:12 · last seen 2026-06-03 05:01:44