Mechanical-Chemical Activation of Cement-Ash Binders to Improve the Properties of Heat-Resistant Mortars.

The article demonstrates the effectiveness of the mechanochemical activation of a cement-ash binder by increasing the specific surface area of the ash and introducing a sodium fluorosilicate additive (NaSiF). It has been experimentally proved that the introduction of a NaSiF additive makes it possible to increase the degree of cement hydration, as well as the intensity of free CaO binding when heating the cement-ash binder in the range of 500 °C to 800 °C. Mechanochemical activation prevents a decrease in the strength of the preheated cement-ash binder.

The Effect of the Type and Amount of Synthetic Fibers on the Effectiveness of Dispersed Reinforcement in Soil-Cements.

The paper deals with mechanical properties of soil-cement composites made with non-cohesive soil and reinforced with dispersed fibers. The research was carried out on the basis of three soil-cement matrices whose compositions varied in terms of the volumetric fraction of cement paste and the water-cement ratio. Two types of polypropylene fibers were used as dispersed reinforcement: single fibrillated-tapes polypropylene fibers (SFPF) and bundles of coiled fibrillated-tapes polypropylene fibers (BCFPF).

Effect of Cement Type on the Mechanical Behavior and Permeability of Concrete Subjected to High Temperatures.

The paper presents experimental investigations concerning the influence of the cement type (CEMI 42.5 R Portland cement and CEMIII/A 42.5 N slag cement-with 53% granulated blast furnace slag) on the mechanical and transport properties of heated concretes.

Effect of Hydration and Carbonation Progress on the Porosity and Permeability of Cement Pastes.

This paper presents the results of comprehensive cement paste porosity and gas permeability tests. The tests conducted concerned ordinary Portland cement (OPC) cement pastes with varying water-cement ratios ranging from 0.3 to 0.