The current context regarding the management of waste obtained from the construction industry, according to European Union laws and directives, requires the imposition of an integrated waste management system. The main objective of this study was to integrate and reuse old plaster waste as a substitute for aggregates in significant proportions in mortar composition and analyzing the impact on the physical and mechanical characteristics of mortar in fresh state and in hardened state. Over periods of 7, 14, and 28 days, the experimental program studied three types of plastering mortars: a standard recipe (without waste) and another two proposed recipes, in which construction waste was re-used as a substitute for aggregates in proportions of 10% and 15%. Results obtained on the fresh properties of the proposed plastering mortars (apparent density, consistency, and segregation trend) indicated a variation (increase/decrease) of 1% to 2.5% compared with the standard recipe. Mechanical strengths showed decreased values; that is, the compressive strength decreased by 11.09% and the flexural strength decreased by 22% when waste replaced aggregates in a proportion of 15%. The results of the experimental program identified the potential of waste plaster, which can replace up to 15% of the aggregates in plaster mortars, which still guarantees their successful use in practice. To reduce the influence of the use of waste on the mechanical strengths, we propose to conduct further investigations (nuclear magnetic resonance, electronic microscopy, and X-ray diffraction) on these mortars reinforced with different types of fibers. The large amount of waste resulting from the rehabilitation of damaged building facades and the fact that there are currently no experimental studies on the reuse of waste from old plaster mortars were the main reasons for the present study examining the possibility of their use in the production of new building materials.

The current framework for managing construction waste, guided by European Union regulations, calls for an integrated waste management system. However, the reuse of old plaster waste, particularly from deteriorated facades, remains underexplored. This study investigates the potential of repurposing old plaster waste as a substitute for aggregates and cement in mortars, with the aim of promoting environmental sustainability and resource efficiency. Three mortar mixes were analyzed: a control mix, a mix with 45% waste replacing aggregates, and a mix with 10% waste replacing cement. Results show that replacing 45% of aggregates with plaster waste led to a 30% reduction in flexural strength, while the 10% cement replacement increased flexural strength by 6%. Compressive strength dropped by 27% and 38% for cement and aggregate replacements, respectively. Despite these reductions, the waste replacement remained within acceptable limits for structural integrity. Further microscopic analysis revealed that the incomplete integration of portlandite particles from the waste contributed to non-uniform bonding and crystal formation, weakening the mortar’s structure. This research demonstrates the feasibility of reusing old plaster waste, offering a novel approach to reducing construction waste and promoting a circular economy. It contributes to filling the knowledge gap on the reuse of plaster mortars while aligning with sustainable construction goals.

Background/Objectives: Colorectal cancer (CRC) is one of the most common and deadly types of cancer. Compared with the classical histopathological approach, this study discusses the application of ¹H NMR and FT-IR techniques for the fast evaluation degree of healing of patients with CRC after surgical intervention. Methods: Native and deproteinized blood plasma collected from 10 patients with confirmed CRC and 20 healthy volunteers were analyzed using ¹H NMR T₂ distributions and FT-IR spectra measured for samples collected before and 7 days after surgery. The average FT-IR spectrum from 20 healthy volunteers is also presented. Principal component analysis (PCA) was performed on the FT-IR spectra. The results were used for further statistical analysis using receiver operating characteristic (ROC) and area under the curve (AUC) and to produce a series of prediction maps using a machine learning library. Results: Both experimental methods combined with analysis methods demonstrated that the native blood plasma samples can be better used to predict the CRC patients’ evolution 7 days after surgery. Three patients showed a significant evolution by ¹H NMR T₂ distribution, correlated to the observation of FT-IR–PCA analysis. Maps of medical state probability were generated using a trained machine learning-based ANN. Conclusions: The experimental measurements combined with an advanced statistical analysis and machine learning were successfully used and show that the healing process of patients with CRC is not linear, from the preoperative state to the state associated with healthy volunteers, but passes through a distinct healing state

In the current framework of sustainable development, stricter international regulations are shaping waste management practices, particularly in the construction sector—one of the main generators of waste. This study investigates the reuse of deteriorated plaster waste from façades scheduled for rehabilitation, by partially replacing cement or aggregates in lime–cement mortars. Four mortar formulations were tested: a reference mix, one with 45% aggregate replacement by plaster waste, one with 10% cement replacement, and another combining the 45% aggregate replacement with polypropylene fibers. Both microstructural and macrostructural analyses were conducted to identify correlations between these levels when incorporating waste and fibers. Results show a decrease in compressive strength (36% for aggregate and 29% for cement replacement) and flexural strength (24% and 18%, respectively) as the replacement ratio increases. However, the inclusion of polypropylene fibers improved the mechanical performance. SEM analysis confirmed significant microstructural variations within the cementitious matrix due to waste incorporation. Despite reduced strength values, all mixtures remained within the limits defined by current standards, validating the feasibility of using plaster waste in mortars and emphasizing its potential to reduce construction waste and promote sustainable development.