Use of Iraq Concrete Scrap as Filler and Aggregate of Heavyweight and Lightweight Concrete

Abstract

<jats:p>the relevance of the paper is due to the search for alternative sources of raw materials for the construction industry, associated with the disposal of man-made waste. The novelty of the article is to identify the scien-tific laws of the influence of demolition waste on buildings and structures on the formation of the micro-structure of lightweight and heavyweight concrete. Concrete waste was prepared as both fillers of cement materials and fine aggregates, based on which concrete with high mechanical properties was created. The mix design was carried out from the point of view of geomimetics, in particular, taking into account the law of affinity of structures. The strength characteristics of concrete mixtures were investigated in accordance with EN 12390-3. In addition, the microstructural, morphological and thermal properties of the raw materials and concrete were determined during 28-day curing. For the first time, the dense microstructure of the com-posite was ensured, both with Portland cement products and with hydration, and, in part, with hydration products of previously unreacted clinker, whose minerals are present in concrete waste and are activated when they are crushed. The use of demolition waste of buildings and structures as a filler of cementing ma-terial when replacing Portland cement up to 20% allows to obtain better compressive strength of both heav-yweight and lightweight concrete.</jats:p>

Композиционное Вяжущее С Энергосберегающим Сырьем Для Высокопрочного Бетона

“…%), что составляет примерно 30 мас. % от исходного портландцемента [7]. Бой газобетона содержит гидросиликаты кальция, синтезируемые в процессе автоклавной обработки при производстве изделия [2].…”

Reuse of concrete and brick scrap as aggregates

“…Добыча таких материалов ведется открытым способом, что подразумевает вывоз в отвал вскрышных пород. За 2021 г. отходы добывающей промышленности составили 7,7 млрд т, то есть более 90 % от общего количества отходов промышленности 1 . Указанный факт обусловливает актуальность применения в качестве заполнителя в бетон отходов промышленности.…”

Mechanical Properties of High-Performance Hybrid Fibre-Reinforced Concrete at Elevated Temperatures

“…The addition of polypropylene fibres in concrete has shown an improvement in the splitting tensile and flexural strength, but not in terms of compressive strength [8,9]. Another common fibre used in research is steel fibres which leads to an increase in concrete's overall mechanical properties such as impact resistance [10,11], ductility [12,13], tensile [2,14] and flexural [15] strengths, and resistance towards crack propagation [16][17][18][19]. The hybridization of steel and propylene fibre is utilized to deliver a balanced enhancement in concrete and the primary purposes of adding two different lengths (short and long) of fibres are to enhance the ductility and tensile strength by the action of these fibres [20][21][22].…”