Modification of the Cementitious System As A Method For Densifying the Inter-Pore Walls of Fiber-Reinforced Foam Concrete

Abstract

This study investigates the effect of complex modification of a cementitious system on hardening behavior and strength formation in cement paste designed for the production of fiber-reinforced foam concrete. Microcalcite, microsilica, and a polycarboxylate-based superplasticizer were used as modifying components. The experimental program included a comparison between a reference mixture without additives and a modified mixture incorporating 5% microcalcite, 5% microsilica, and 1% superplasticizer by mass of cement. Compressive strength was evaluated after 3, 7, and 28 days of curing, and the phase composition of the cement matrix was analyzed by X-ray diffraction. The results showed that the complex additive did not lead to a significant increase in early-age strength, but contributed to the development of structure-forming processes by 28 days. X-ray diffraction analysis confirmed the presence of portlandite, calcite, residual clinker minerals, and an amorphous region related to calcium silicate hydrate phases. These findings indicate that the combined use of microcalcite, microsilica, and superplasticizer promotes densification of the cement matrix and can be applied to modify the cementitious binder for fiber-reinforced foam concrete