Potential of Reusing 3D Printed Concrete (3DPC) Fine Recycled Aggregates as a Strategy towards Decreasing Cement Content in 3DPC.

This paper explores the new potential strategy of using fine recycled aggregates (fRA) derived from waste 3D printed concrete (3DPC) as a substitute for cement in additive manufacturing. This study hypothesizes that fRA can optimize mixture design, reduce cement content, and contribute to sustainable construction practices. Experimental programs were conducted to evaluate the fresh and hardened properties, printability window, and buildability of 3DPC mixes containing fRA.

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.

Hygric Properties of Machine-Made, Historic Clay Bricks from North-Eastern Poland (Former East Prussia): Characterization and Specification for Replacement Materials.

This paper deals with the hygric characterization of early 20th century machine-made clay bricks, representative of great number of historical buildings in north-eastern Poland. Heritage buildings have a high potential for adaptive reuse, which is strictly connected with an urge for knowledge about the properties of these existing building envelopes. To better understand the hygric behavior of historic buildings, various experimental laboratory tests, including density, water absorption, compressive strength and freeze-thaw resistance, were conducted.

Modification of Lightweight Aggregate Concretes with Silica Nanoparticles-A Review.

The use of lightweight concrete (LWC) for structural and non-structural applications has attracted great interest in recent years. The main benefits include reduced deadload of structural elements and generally lower production and transportation costs. However, a decrease in concrete density often leads to a decrease in strength and durability.

The Effects of Temperature Curing on the Strength Development, Transport Properties, and Freeze-Thaw Resistance of Blast Furnace Slag Cement Mortars Modified with Nanosilica.

This investigation studies the effects of hot water and hot air curing on the strength development, transport properties, and freeze-thaw resistance of mortars incorporating low-heat blast furnace slag cement and nanosilica (NS). Mortar samples were prepared and stored in ambient conditions for 24 h. After demolding, mortar samples were subjected to two different hot curing methods: Hot water and hot air curing (40 °C and 60 °C) for 24 h.

The Effect of Lightweight Concrete Cores on the Thermal Performance of Vacuum Insulation Panels.

The performance of vacuum insulation panels (VIPs) is strongly affected by several factors, such as panel thickness, design, quality of vacuum, and material type. In particular, the core materials inside VIPs significantly influence their overall performance. Despite their superior insulation performance, VIPs are limited in their widespread use as structural materials, because of their low material strength and the relatively expensive core materials.

Influence of Nanosilica on Mechanical Properties, Sorptivity, and Microstructure of Lightweight Concrete.

This study presents the results of an experimental investigation of the effects of nanosilica (NS) on the strength development, transport properties, thermal conductivity, air-void, and pore characteristics of lightweight aggregate concrete (LWAC), with an oven-dry density <1000 kg/m. Four types of concrete mixtures, containing 0 wt.%, 1 wt.

The Influence of Nanomaterials on the Thermal Resistance of Cement-Based Composites-A Review.

Exposure to elevated temperatures has detrimental effects on the properties of cementitious composites, leading to irreversible changes, up to total failure. Various methods have been used to suppress the deterioration of concrete under elevated temperature conditions. Recently, nanomaterials have been introduced as admixtures, which decrease the thermal degradation of cement-based composites after exposure to high temperatures.

Antimicrobial Activity of Al₂O₃, CuO, Fe₃O₄, and ZnO Nanoparticles in Scope of Their Further Application in Cement-Based Building Materials.

Nanoparticles were proposed as antibacterial cement admixtures for the production of cement-based composites. Nevertheless, the standards for evaluation of such admixtures still do not indicate which model organisms to use, particularly in regard to the further application of material. Apart from the known toxicity of nanomaterials, in the case of cement-based composites there are limitations associated with the mixing and dispersion of nanomaterials.

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.

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 Influence of Nano-Fe3O4 on the Microstructure and Mechanical Properties of Cementitious Composites.

In the last decade, nanotechnology has been gathering a spectacular amount of attention in the field of building materials. The incorporation of nanosized particles in a small amount to the building materials can influence their properties significantly. And it can contribute to the creation of novel and sustainable structures.