The Effect of Mineral Admixtures and Fine Aggregates on the Characteristics of High-Strength Fiber-Reinforced Concrete

Abstract

Introduction: the article discusses the effect of the complex of active mineral additives consisting of silica and fly ash, and a fine aggregate, including finely ground natural-white quartz sand for partial replacement of river sand, on the mechanical properties of high-strength concrete containing steel fiber. Materials and methods: high-strength concrete containing Dramix®3D 65/35 steel fiber in the amount of 100 kg per 1 m3 of concrete mixture was suggested where 22% to 100% of river sand was replaced by finely ground white natural sand of the particle size of 5 to 1800 μm and containing the complex of active mineral additives for partial replacement of cement as part of a multicomponent binder, consisting of low-calcium fly ash of thermal power plants and silica and containing, respectively, 20, 30, 40% fly ash and from 5 to 15% silica by weight of the binder. Results: research results have shown that 100% replacement of river sand with finely ground natural white sand, in concrete containing 20% of the mass as part of a multicomponent binder, fly ash and from 5 to 15% by weight of silica, contributes to the increase of its strength properties: the values of concrete compressive strength after 28 days were in the range from 118.5 to 128 MPa, tensile strength during bending and splitting, respectively, from 18.8 to 25.4 MPa and from 10.2 to 11.9 MPa, which is higher than the strength of concrete samples containing river sand. Conclusions: the achieved results have demonstrated the efficiency of using finely ground natural white sand as an alternative to river sand for producing high-strength concrete, thus helping to save the river sand resources in Vietnam. The use of fly ash and micro silicon, which are power and metallurgy wastes, as part of a multicomponent binder in order to partially replace cement reduces the carbon footprint in the production of binders and will also have a beneficial effect on environmental protection against industrial waste pollution.

Increase in physical and mechanical properties of decorative concretes for the post‐war restoration of residential and public buildings in the Kharkiv region with the addition of highly dispersed calcite (chalk)

“…Surface chalk particles covered free silicic acid. At interacted with calcium hydroxide and silicic acid low basic calcium hydrosilicates are created to can be explain to create hydrate neoplasms is calcium hydrocarboaluminates [7,11]. Addition efficiency highly dispersed chalk is determined not only interacted with clinker minerals but also compaction of the microstructure due to the placement of grains of the addition in the gaps between the grains of cement.…”

“…in relation to binders and hydration products [3]. It should be noted that the amount of mineral additions introduced varies from a fraction of a percent to several tens of percent of the mass of the binder [4,5,6,7].…”

The use of technogenic carbon in gypsum compositions for green building

“…This leads to the quenching of thermally activated and ready to enter into chemical interaction with water minerals and a decrease in the hydraulic activity of ash and slag, which limits their use as additives for cement [8]. The main components of the dry-removal ash and slag mixture, mainly silica and alumina, are in a highly reactive state, which makes it possible to use it as an active mineral additive in cement in order to save expensive clinker, increase output and reduce the cost of cement [9,10].…”

The Use of Aluminosilicate Ash Microspheres from Waste Ash and Slag Mixtures in Gypsum-Lime Compositions

“…Thus, the use of small aggregates in the form of ash and slag waste components has a positive effect on the strength characteristics of artificial stone on alternative types of binder [ 36 , 37 , 38 , 39 ], i.e., its use is possible not only in systems based on a cement binder, as noted in [ 40 ], and concrete [ 41 , 42 ]. As a rule, a positive effect is due not only to packing density [ 43 ], but also to a change in the morphology of gypsum crystals formed during hydration and curing [ 43 ].…”