The paper reviews the properties of cement composites reinforced with short fibres. The effect of natural fibres was investigated: cotton, sisal, jute, ramie, bamboo, and synthetic fibres: polymer and polypropylene. It was noticed that the fibres change the consistency of the mixture up to 15%. In the composite flexural strength tests, a change in strength by +/− 8% was observed, depending on the type of fibres used. The research shows that the use of natural fibres had a positive effect on the compressive strength by 27%, while the use of synthetic fibres caused its decrease by 4%. Additionally, it was noticed that the chemical composition, the diameter and the total length of the fibres in the element have an impact on the composite shrinkage. The fibre-containing composites showed an 8% higher water absorption compared to the non-fibre samples. The exception is the ramie fibres, which reduce water absorption. In general, a positive effect of natural fibers on the properties of cement composites has been noticed, however, in case of natural fibres application, a thorough further properties investigation is recommended.

Lightweight concrete (LWC) is a group of cement composites of the defined physical, mechanical, and chemical performance. The methods of designing the composition of LWC with the assumed density and compressive strength are used most commonly. The purpose of using LWC is the reduction of the structure’s weight, as well as the reduction of thermal conductivity index. The highest possible strength, durability and low thermal conductivity of construction materials are important factors and reasons for this field’s development, which lies largely in modification of materials’ composition. Higher requirements for construction materials are related to activities aiming at environment protection. The purpose of the restrictions is the reduction of energy consumption and, as a result, the reduction of CO₂ emission. To limit the scope of time-consuming and often high-cost laboratory works necessary to calibrate models used in the test methods, it is possible to apply Artificial Neural Networks (ANN) to predict any of the concrete properties. The aim of this study is to demonstrate the applicability of this tool for solving the problems, related to establishing the relation between the choice of type and quantity of lightweight aggregates and the porosity, bulk density and compressive strength of LWC. For the tests porous lightweight Granulated Expanded Glass Aggregate (GEGA) and Granulated Ash Aggregate (GAA) have been used.

Global economic growth causes an increase in natural resources exploitation, particularly in construction branch. The growing use of electricity contributes to climate change. Therefore, it is necessary to search the solutions, which will allow for reducing natural resources exploitation. One of the many opportunities to do that is the application of the recycled materials. The authors of the given article have analyzed three variants of construction solutions. One of them was the production of the walls of a building from reinforced concrete prefabricates with styrofoam insulation layer. The second variant for analysis were prefabricated walls from lightweight concrete, made of sintered clay aggregate with a foam core. The third proposed variant was a system of multi-layered walls, which was made of lightweight concrete with granulated expanded glass aggregate (GEGA). The main objective of the research was to assess the use of lightweight GEGA prefabricates, focusing on economic and technological aspects of the solution. The authors have analyzed the entire construction costs; ceilings and stairs were assumed as reinforced concrete elements. In calculations, the weight of the elements was taken into account, as well as transportation and mounting costs. On the basis of this cost analysis, it was concluded that the use of prefabricated element, made of lightweight concrete with GEGA, could be a replacement for the solutions, widely applied until these days. The analysis has also shown that the use of prefabricates with GEGA is sensible from the economic viewpoint, as it allows for saving construction time. Moreover, the solutions, proposed here, allow for saving natural resources and assuming a more environmentally friendly and caring attitude.

This study systematically studied the impact strength of Geopolymer concrete (GC) integrating fly ash, slag, and silica fume, reinforced with four natural fibers including sisal, jute, coir, and flax at varying aspect ratios. The primary objectives are to analyze the influence of fiber length on initial cracking number (J1), failure number (J2), crack-bridging mechanisms, and failure modes under impact loading. This study presents a unique contribution by thoroughly examining the impact of fiber aspect ratio in multi-binder GC, offering critical insights into optimizing fibrous GC for improved structural performance and resilience. The impact performance of GC was influenced by both fiber type and length. Coir fibers enhanced J1 by up to 66% and J2 by 171.43%, with optimal energy absorption at 60 mm. Flax and jute fibers showed peak performance at 40 mm, with J2 improvements of 75.82% and 100%, respectively, while longer lengths led to dispersion issues and diminished gains. Sisal fiber at 40 mm offered balanced enhancement (J1: 50%, J2: 117.58%), whereas the highest J2 (135.16%) was achieved with 60 mm, accompanied by a moderate drop in J1, indicating that excessive fiber lengths may hinder bonding efficiency.