Reactive Powder Concrete Microstructure and Particle Packing

Abstract

The subject of this study is the dispersed composition of multicomponent cement systems. This study aims to reduce interparticle voids, increasing the strength and concentration of the solid phase. The investigated concrete mixture contained two fine aggregate fractions, granite-gabbro crushed stone of 5–10 mm fraction, Portland cement of CEM I 42.5N class, finely dispersed granular blast furnace slag, microsilica, highly dispersed cement fraction, superplasticizer Glenium 430, and high-valence hardening accelerator. A laser analyzer determined the shape and size of dispersed particles of the components. The structure of the cement stone was studied by scanning microscopy, thermographic, and X-ray phase analysis methods. The strength of concrete with an optimized dispersed composition at the age of 2 days was 52, 63, and 74 MPa, while that at the age of 28 days was 128, 137, and 163 MPa. For this concrete, the consumption of multicomponent cement was 650, 700, and 750 kg/m3, respectively. The high efficiency of the application of bimodal clinker component and granulated blast-furnace slag is shown. It is established that the optimal content of nanoscale additives, including microsilica, should be insignificant and determined experimentally.

Experimental Research on Mechanical Properties of Carbon Fiber-Reinforced Reactive Powder Concrete after Exposure to Cryogenic Temperatures

“…Nowadays, reactive powder concrete (RPC) is widely used because of its good mechanical properties and durability [10][11][12][13]. Adding fibers to RPC has been shown to greatly improve its ductility, inhibit cracking, and increase tensile strength [14][15][16][17].…”

Influence of the addition of glass from long neck bottles in the properties of the reactive powder concrete

“…The mixture of the raw materials of the RCP aims to obtain a more homogeneous mass and an increase in compactness, optimized by refined granulometry with consequent improvement in the mechanical properties between paste and aggregate and in the ductility of the concrete. All this concern is based on two crucial points: the increase in the homogeneity of the mixture (which occurs with the removal and replacement of coarse aggregates by ultrafine particles) and the resulting formation of a much less porous microstructure, especially regarding the aggregate-paste interface (Wang et al, 2022;Velichko & Vatin, 2022;Qing-hua et al, 2022). According to Zdeb (2016), one of the most significant characteristics that improves the microstructure and distinguishes the reactive powder concrete from any other material based on high performance cement is the removal of the large aggregate, increasing the resistance in the matrix and homogeneity.…”