Nanoparticles are defined as ultrafine particles sized between 1 and 100 nanometres in diameter. In recent decades, there has been wide scientific research on the various uses of nanoparticles in construction, electronics, manufacturing, cosmetics, and medicine. The advantages of using nanoparticles in construction are immense, promising extraordinary physical and chemical properties for modified construction materials. Among the many different types of nanoparticles, titanium dioxide, carbon nanotubes, silica, copper, clay, and aluminium oxide are the most widely used nanoparticles in the construction sector. The promise of nanoparticles as observed in construction is reflected in other adoptive industries, driving the growth in demand and production quantity at an exorbitant rate. The objective of this study was to analyse the use of nanoparticles within the construction industry to exemplify the benefits of nanoparticle applications and to address the short-term and long-term effects of nanoparticles on the environment and human health within the microcosm of industry so that the findings may be generalised. The benefits of nanoparticle utilisation are demonstrated through specific applications in common materials, particularly in normal concrete, asphalt concrete, bricks, timber, and steel. In addition, the paper addresses the potential benefits and safety barriers for using nanomaterials, with consideration given to key areas of knowledge associated with exposure to nanoparticles that may have implications for health and environmental safety. The field of nanotechnology is considered rather young compared to established industries, thus limiting the time for research and risk analysis. Nevertheless, it is pertinent that research and regulation precede the widespread adoption of potentially harmful particles to mitigate undue risk.

Fibres have been used in construction materials for a very long time. Through previous research and investigations, the use of natural and synthetic fibres have shown promising results, as their presence has demonstrated significant benefits in terms of the overall physical and mechanical properties of the composite material. When comparing fibre reinforcement to traditional reinforcement, the ratio of fibre required is significantly less, making fibre reinforcement both energy and economically efficient. More recently, waste fibres have been studied for their potential as reinforcement in construction materials. The build-up of waste materials all around the world is a known issue, as landfill space is limited, and the incineration process requires considerable energy and produces unwanted emissions. The utilisation of waste fibres in construction materials can alleviate these issues and promote environmentally friendly and sustainable solutions that work in the industry. This study reviews the types, properties, and applications of different fibres used in a wide range of materials in the construction industry, including concrete, asphalt concrete, soil, earth materials, blocks and bricks, composites, and other applications.

This paper describes the experimental investigation of relationship between splitting tensile strength and flexural strength with the compressive strength of concrete containing waste PET as fine aggregates replacement. Waste PET was reprocesses and used as the artificial fine aggregate at the replacement volume of 25%, 50% and 75%, Cylindrical and prism specimens were tested to obtain the compressive, splitting tensile and flexural strength at the age of 28 days. Based on the investigation, a relationship for the prediction of splitting tensile and flexural strength was derived from the compressive strength of concrete containing waste PET as fine agglegate replacement.

Several trillion cigarettes are produced worldwide annually, resulting in tonnes of cigarette butt waste. Cigarette butts accumulate in the environment due to the poor biodegradability of the cellulose acetate filters. Results from a study on recycling cigarette butts into fired clay bricks are presented. Five different soil–cigarette butts mixes with different percentages of cigarette butts were used. The physico-mechanical properties of manufactured bricks including compressive strength, flexural strength, density, water absorption and thermal conductivity are discussed. The results show that the density of fired bricks was reduced significantly, by up to 30%, depending on the percentage of cigarette butts incorporated into the raw materials. Similarly, the compressive strength of bricks decreased according to the percentage of cigarette butts included in the mix, and the estimated values of thermal conductivity were also reduced significantly. The results also show that the mixing time has a considerable effect on the properties of the fired clay bricks tested. Furthermore, the leachate test results revealed only trace amounts of heavy metals. It was concluded that cigarette butts can be regarded as a potential addition to the raw materials used in the manufacture of lightweight fired bricks and, furthermore, that recycling cigarette butts in bricks is a very practical and potentially significant contribution in terms of a sustainable solution to one of the serious environmental pollution problems in the world.