Development and testing of ecological lime-based building composites modified with extracts of fermented plants

OPUS 30

Funding Organization: National Science Centre

Leader: Lublin University of Technology

Partner: Warsaw University of Technology

Project title: Development and testing of ecological lime-based building composites modified with extracts of fermented plants

Agreement number: UMO-2025/59/B/ST8/03063

Project implementation period: 01.10.2026 - 30.09.2030

Principal Investigator (Lublin University of Technology): dr inż. Przemysław Brzyski

Project value: 3 124 260,00 PLN

Funds granted for Lublin University of Technology: 1 612 680,00 PLN

Funds granted for Warsaw University of Technology: 1 511 580,00 PLN

Abstract: The project will involve developing a procedure for preparing the organic additive and incorporating it into lime-based mixtures. Different additive concentrations, fermentation methods and conditions, and hemp shive contents will be investigated. This approach will enable the identification of relationships between composite composition, microstructure, and functional properties. The experimental programme will include an assessment of fresh mixture properties, such as consistency, viscosity, air content, and water retention capacity. Hardened composites will be tested for compressive, tensile, and flexural strength under different humidity conditions and CO₂ concentrations during curing. Additional investigations will cover shrinkage, water vapour permeability, moisture sorption, specific heat capacity, thermal conductivity, and capillary water absorption.

To explain the mechanisms of interaction between organic additives and the mineral binder, detailed microstructural investigations will be performed. The analytical methods will include mercury intrusion porosimetry, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron and digital microscopy, and micro-computed tomography (mCT). The results will be used to establish relationships between pore structure, phase composition, and the mechanical and hygrothermal properties of the developed composites.

An important part of the project will be numerical modelling at micro- and macroscales, conducted in cooperation with the scientific partner, Warsaw University of Technology. Based on the actual composite microstructure reconstructed from mCT scans, a microscale model will be developed to predict effective hygrothermal properties, including material anisotropy. A second model will simulate coupled heat and moisture transport in building envelopes incorporating the developed composites and support the optimisation of their layered structure. Both models will be calibrated and validated using experimental results, including investigations of dynamic heat and moisture transport processes. Wall-scale experiments will also be conducted to evaluate the hygrothermal behaviour of the developed building envelopes under conditions representative of real-life operation.

The expected outcome is to determine the potential of fermented plant extracts as natural modifiers of lime-based composites, improving selected material properties without significantly compromising water vapour transport and moisture buffering capacity. By varying the composition of the mixtures, materials suitable for thermal insulation, finishing, and renovation applications will be identified. The project will contribute to advancing knowledge within the discipline of civil engineering, geodesy and transport, particularly in building materials engineering, building physics, and the design of sustainable building envelopes with improved functional and environmental performance.