Self-compacting concrete with limestone powder for transport infrastructure

Abstract

Abstract. At the beginning of XXI century in civil engineering and buildings of transport infrastructure, such as tunnels, elements of bridges, viaducts and roads, it is more expedient to use conventionally vibrated concretes which have almost universally replaced prefabricated constructions. However, in objects with high congested reinforcement or in cases where vibration is impossible it is more preferable to apply self-compacting concrete (SSC) mixtures. SCC possesses the ability to take form shape without any mechanical aid. The most important requirement for SCC is high flowability without the segregation of aggregate during placement. Despite the low water-cement ratio of the fresh self-compacting concrete mixture the bleeding is still possible. That is why fillers such as natural pozzolana, calcined clay (metakaolin), silica fume, fly-ash, slag, and quarry dusts should be used. Furthermore, mineral admixtures can improve energy efficiency and particle packing, decrease cost and permeability of self-compacting concrete. In this study, the properties of SCC with limestone powder as partial replacement of Portland cement was established by applying mathematical experiment planning method. The obtained SCC gave high early compressive strength within 3 days in the range of 41.3 MPa while its 28 day strength ranged of 69.0 MPa. The result of this study indicated the possibility of adding limestone powder in SCC with optimum percentage content around 38 %. The researched SCC had density of hardened and fresh concrete mix in the ranges of 2438 kg/m3 and 2452 kg/m3 respectively. The investigated SCC concrete with limestone powder showed high rate of water permeability in the range of 1.6 MPa (W16) and high frost resistance in the ranges of F2400. It can be explained by additive's high water retention capacity and increase of hydration degree and, as a consequence, decrease of capillary porosity. That is why the developed SCC with limestone powder has high compressive strength and excellent durability performance.Аннотация. На объектах гражданского строительства и транспортной инфраструктуры в конструкциях, имеющих высокий коэффициент армирования, и в случаях, когда вибрирование бетонных смесей осуществить не представляется возможным, необходимо применение эффективных самоуплотняющихся бетонных смесей, которые получили широкое распространение в последние десятилетия в мировой практике. В работе представлены результате экспериментальных исследований при разработке состава самоуплотняющегося бетона для объектов транспортной инфраструктуры с использованием наполнителей на основе отходов дробления карбонатных пород. Для оптимизации состава применялся трехфакторный метод математического планирования эксперимента, композиционный план на кубе типа В3, обеспечивающий максимальную прочность при достижении требуемых технологических показателей.Установлено, что введение эффективного разжижжителя в виде гиперпластификатора, значительно снижает водосодержание бетонной смеси, что предотвращает расслаиваемость самоуплотняющегося ...

Industrial Waste as Components of Building Materials

“…Up to 45% of the processed rock goes to waste. Waste is partially processed -as an aggregate in the compositions of low-grade concrete and mortars, in the compositions of dry building mixtures, as aggregate and mineral flour in asphalt concrete [6][7][8][9][10]. But, nevertheless, waste accumulates in huge quantities, and at least occupies territories and becomes dusty.…”

“…The use of carbonate waste as additives is also associated with their availability and good grindability. Most importantly, the possibility of chemical interaction of finely ground carbonates with cement has now been proven [6,9].…”

Farklı viskozite düzenleyici katkı maddelerinin kendiliğinden yerleşen harçların mekanik ve akış özelliklerine etkisi

“…However, it is necessary to take various precautions to prevent the risk of reduction in the segregation resistance of concrete with the use of these additives. It is known that fine materials such as silica fume, fly ash, metakaolin are included in the mixture to prevent segregation and increase the viscosity of the mixture [1][2][3][4]. However, while these materials provide advantages such as reducing the amount of superplasticizer and increasing workability, they reduce early strength, cause shrinkage and slow down the settling time [5].…”

Strengthening the historical constructions made of limestone by treating with silicic acid based material

“…In Russian Federation, there is an active development of the construction industry, in this regard, many authors are considering the introduction of their own resources in the manufacture of building materials. Different constructional materials are explored in the work of different authors [4,5,14,[6][7][8][9][10][11][12][13].…”