Lavender and Black Pine Waste as Additives Enhancing Selected Mechanical and Hygrothermal Properties of Cement Mortars.

The paper presents the mechanical and hygrothermal properties of cement mortars containing bio-powders made from lavender waste and black pine wood. The wastes were mechanically ground with a hammer mill to a fraction not exceeding 0.5 mm and then dried in air-dry conditions.

New Method for Photoactive Cement Preparation-Selected Mechanical Properties and Photocatalytic Activity of New Materials.

In this study, a new method of obtaining photoactive cements is presented. The goal was to obtain photoactive cements using a method that could reduce the production costs. In the study, an intermediate product from the production of titanium dioxide using the sulfate method, taken from the installation before the calcination process, was used to obtain photoactive cements.

Functional BiO/GdO Silica-Coated Structures for Improvement of Early Age and Radiation Shielding Performance of Cement Pastes.

This study presents a new approach towards the production of sol-gel silica-coated BiO/GdO cement additives towards the improvement of early mechanical performance and radiation attenuation. Two types of silica coatings, which varied in synthesis method and morphology, were used to coat BiO/GdO structures and evaluated as a cement filler in Portland cement pastes. Isothermal calorimetry studies and early strength evaluations confirmed that both proposed coating types can overcome retarded cement hydration process, attributed to BiO presence, resulting in improved one day compressive strength by 300% and 251% (depending on coating method) when compared to paste containing pristine BiO and GdO particles.

Mechanical Strength and Thermal Properties of Cement Concrete Containing Waste Materials as Substitutes for Fine Aggregate.

The increasing volume of waste and the requirements of sustainable development are the reasons for the research on new waste management concepts. The research results presented in this paper show the effect of recycled aggregate on the selected properties of cement concrete. The aggregates obtained from three types of wastes are tested: recycled concrete paving, crushed ceramic bricks, and burnt sewage sludges.

Effect of Nano-SiO on the Microstructure and Mechanical Properties of Concrete under High Temperature Conditions.

The aim of the research was to determine how the admixture of nanosilica affects the structure and mechanical performance of cement concrete exposed to high temperatures (200, 400, 600, and 800 °C). The structural tests were carried out on the cement paste and concrete using the methods of thermogravimetric analysis, mercury porosimetry, and scanning electron microscopy. The results show that despite the growth of the cement matrix's total porosity with an increasing amount of nanosilica, the resistance to high temperature improves.

The Thermal Parameters of Mortars Based on Different Cement Type and W/C Ratios.

This study examines the thermal parameters of mortars based on different cement type and water-cement W/C ratios. The presented relationships are important from the point of view of thermal insulation of the entire building component, of which the mortar is a part. The thermal properties of the mortar, and in particular its dependence on the degree of moisture, is important information from the point of view of hygrothermal simulations of building components.

Moisture Influence on Compressive Strength of Calcium Silicate Masonry Units-Experimental Assessment and Normative Calculations.

This paper primarily assesses the scale of adverse changes to the compressive strength of different types of silicates due to the influence of moisture. The study covers three groups of silicate units of different strength classes-15, 20 and 25-obtained from three different manufacturers. It was demonstrated that in all studied groups, moisture significantly decreased the compressive strength by about 30-40%.

The Effect of Aggregate Shape on the Properties of Concretes with Silica Fume.

The paper examines the impact of aggregate shape on the compressive strength and thermal properties of concretes with silica fume based on two different aggregates: natural round gravel aggregate and crushed basalt aggregate. Compressive strength and thermal properties of individual concretes were determined during the first year of specimens curing. Additionally, porosity tests were conducted using mercury intrusion porosimetry and optical porosimetry.