Supplementary data to "Gypsum-promoted non-ureolytic biocementation of heterogeneous demolition residues by sulfate-bearing mineral formation" paper

Authors: V. Nežerka [1]*, K. Kliková [2], P. Holeček [1], D. Koňáková [1], H. Stiborová [2]

Affiliations: [1] Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 166 29 Praha 6, Czech Republic
[2] Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, Technická 1903/3, 166 28 Praha 6, Czech Republic

Corresponding Author: Václav Nežerka (vaclav.nezerka@cvut.cz)

Project Funding: This research was supported by the Czech Science Foundation (GA ČR), project No. 25-16403S ("Harnessing facultative anaerobes for upcycling finest fractions from crushed waste concrete").

1. Dataset Overview

This repository contains the raw experimental data associated with the research article "Biologically-Mediated Recycling of Inert Demolition Residues through Thaumasite Formation Promoted by Waste Gypsum."

The study investigates the use of Sutcliffiella cohnii DSM 6307 (formerly Bacillus cohnii) to biologically consolidate fine-grained demolition waste. The research compares a reactive waste concrete fine (WCF-C) against two inert heterogeneous residues (HM1, HM2). The dataset includes quantitative X-ray Diffraction (XRD) phase analysis, auxiliary spectroscopic data (FTIR, Raman), and the project's Data Management Plan.

2. File Structure and Description

A. Quantitative Phase Analysis (XRD)

The primary mineralogical data is provided in .csv format, extracted from Rietveld refinement of XRD patterns.

• XRD_composition_newTechnology.xlsx - WCF-C.csv: Phase composition (wt%) for the reactive waste concrete fines (WCF-C) under various treatments (30°C vs 20°C, with/without gypsum).
• XRD_composition_newTechnology.xlsx - HM1.csv: Phase composition (wt%) for Heterogeneous Material 1 (HM1 - calcium/AAC rich).
• XRD_composition_newTechnology.xlsx - HM2.csv: Phase composition (wt%) for Heterogeneous Material 2 (HM2 - silica/brick rich).

Column Legend for CSV files:

• name: Mineral phase name (e.g., Calcite, Quartz, Ettringite, Gypsum).
• Crystal System, COD/ICDD: Crystallographic reference data.
• [Sample-ID] (e.g., C-G-30, H1-20): Columns containing weight percentage (wt%) values for specific samples.
  • N-: Negative (sterile) control.
  • C / H1 / H2: Material type (WCF-C, HM1, HM2).
  • G: Gypsum added.
  • 20 / 30: Incubation temperature (°C).
  • -0: Single-dose nutrient protocol (absence of this suffix implies repeated dosing).

B. Auxiliary Laboratory Reports

Raw data files from supplementary analyses that were conducted but not fully detailed in the main manuscript text due to limited diagnostic value for this specific material set.

• FTIR_data.zip: Raw Fourier-transform infrared spectroscopy data.
• Raman_data.zip: Raw Raman spectroscopy data.
• Note: These files are provided for completeness and transparency.

C. Project Documentation

• MICP-WCF_DMP_v1.docx: The Data Management Plan (DMP) for the project GA CR 25-16403S, detailing data handling, ethics, and storage protocols.

3. Methodology Summary

Materials: Three types of demolition waste fines were tested:

1. WCF-C: Reactive, portlandite-rich waste concrete fines.
2. HM1: Inert, mixed demolition waste (AAC, mortar, concrete).
3. HM2: Inert, silica-rich waste (brick, tile, mortar). Promoter: Waste gypsum plaster was added to selected samples (10 wt% replacement).

Biocementation Protocol:

• Bacterial Strain: Sutcliffiella cohnii DSM 6307.
• Cultivation: 24h at 20°C or 30°C in LB broth + NaHCO3 buffer (pH ~9.6).
• Sample Preparation: 26.4 g waste fines (or 24 g fines + 2.4 g gypsum) mixed with 10 mL bacterial suspension (OD600 = 5.0).
• Treatments:
  • Single-dose: One-time application of bacteria + nutrients.
  • Repeated-dose: Periodic addition of nutrient solution over 30 days.
• Incubation: Samples were cured at 20°C or 30°C for 30 days.

Analytical Methods:

• XRD: Quantitative phase analysis using Rietveld refinement to determine mineralogical changes (consumption of gypsum/portlandite, formation of calcite/AFt phases).
• SEM-EDS/TGA: (Results presented in the main paper, corroborating the XRD data).

4. Key Findings

The data demonstrates two distinct consolidation mechanisms:

1. Reactive WCF-C: Consolidates via intrinsic portlandite hydration, enhanced by bacteria to form Ettringite-group minerals.
2. Inert HM1/HM2: Requires both bacteria and gypsum. The mechanism shifts from calcite precipitation to the formation of Thaumasite/AFt phases (and amorphous precursors), consuming the added gypsum to bind the inert silica-rich matrix.

5. License and Usage

This dataset is licensed under the Creative Commons Attribution 4.0 International (CC BY 4.0). You are free to share and adapt the material as long as appropriate credit is given to the authors.