Elzbieta Horszczaruk

The model of abrasive wear of concrete in hydraulic structures

Abrasion wear of concrete in hydraulic construction is caused by movement of rubble carried by water. Difficulties in methodology of modelling this process in a laboratory scale constitute an obstacle to the rational assessment of influence of material and environmental conditions on durability of objects exposed to these actions. This paper presents a new concept of testing the abrasion of concrete by rubble carried by water, modelling the natural mechanisms present in the environment. It was shown that loss of mass in abraded concrete can be expressed as function of work by the abrasive mix and a material parameter depending on composition and independent of the intensity of environmental action. The results of tests allowed the criteria to be given for the selection of the composition of concrete exposed to abrasion-wear.

Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials

The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide) were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100%) to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed.

Evaluation of the Effects of Crushed and Expanded Waste Glass Aggregates on the Material Properties of Lightweight Concrete Using Image-Based Approaches

Recently, the recycling of waste glass has become a worldwide issue in the reduction of waste and energy consumption. Waste glass can be utilized in construction materials, and understanding its effects on material properties is crucial in developing advanced materials. In this study, recycled crushed and expanded glasses are used as lightweight aggregates for concrete, and their relation to the material characteristics and properties is investigated using several approaches. Lightweight concrete specimens containing only crushed and expanded waste glass as fine aggregates are produced, and their pore and structural characteristics are examined using image-based methods, such as scanning electron microscopy (SEM), X-ray computed tomography (CT), and automated image analysis (RapidAir). The thermal properties of the materials are measured using both Hot Disk and ISOMET devices to enhance measurement accuracy. Mechanical properties are also evaluated, and the correlation between material characteristics and properties is evaluated. As a control group, a concrete specimen with natural fine sand is prepared, and its characteristics are compared with those of the specimens containing crushed and expanded waste glass aggregates. The obtained results support the usability of crushed and expanded waste glass aggregates as alternative lightweight aggregates.

Waste-free synthesis of silica nanospheres and silica nanocoatings from recycled ethanol–ammonium solution

In this study, ethanol–ammonium recovery using a distillation system was evaluated. The experimental design was used to evaluate the possibility of solvent re-use and the influence of distillation on the recovery yield, ethanol–ammonium ratio (catalyst concentration) and size of the obtained nanostructures. The synthesised silica nanospheres from distilled ethanol–ammonium were compared in terms of size and shape (ammonium concentration) to the nanostructures obtained from filtrated and centrifuged solvents. The results showed that the process for ethanol–ammonium recovery proposed in this work, provides a large potential for reducing the amount of waste from the synthesis.

Application of Nanomaterials in Production of Self-Sensing Concretes: Contemporary Developments and Prospects

Abstract In the recent years structural health monitoring (SHM) has gathered spectacular attention in civil engineering applications. Application of such composites enable to improve the safety and performance of structures. Recent advances in nanotechnology have led to development of new family of sensors - self-sensing materials. These materials enable to create the so-called “smart concrete” exhibiting self-sensing ability. Application of self-sensing materials in cement-based materials enables to detect their own state of strain or stress reflected as a change in their electrical properties. The variation of strain or stress is associated with the variation in material’s electrical characteristics, such as resistance or impedance. Therefore, it is possible to efficiently detect and localize crack formation and propagation in selected concrete element. This review is devoted to present contemporary developments in application of nanomaterials in self-sensing cement-based composites and future directions in the field of smart structures.