Influence of Metakaolin Incorporation on the Physical-Mechanical Performance of Structural Repair Mortar

Tolentino E.O.G.; Maravi H.K.H.; Sanchez J.J.T.; Robles L.C.S. · SSRG International Journal of Civil Engineering (2026) · DOI: 10.14445/23488352/ijce-v13i8p113

Resumen

The deterioration of buildings and infrastructure creates a need for repair materials with adequate mechanical performance and practical applicability. The study focused on evaluate the effect of replacing part of the cement with metakaolin on the fresh-state and mechanical behavior of structural repair mortar. Under this premise, an experimental study was designed with a mix targeting 250 kg/cm², prepared following the ACI method, where the reference mortar was compared with three mixtures in which part of the cement was replaced by 5%, 10%, and 15% metakaolin. The fresh mortar was evaluated through flow, air content, and setting time tests, as well as hardened mortar was also tested for compressive and flexural strength after 7, 14, and 28 days of curing. In general, adding metakaolin reduced flow from 101.48% to 96.37% and increased air content from 3.53% to 5.09% as the dosage increased. Likewise, initial setting time decreased from 344.60 min to 334.70 min and final setting time from 495.40 min to 455.10 min. Regarding mechanical performance, the most favorable response was obtained with 10% metakaolin, reaching a compressive strength of 284.38 kg/cm² and a flexural strength of 41.03 kg/cm² at 28 days. Among the tested mixtures, the 10% metakaolin dosage gave the best overall response, since it kept a good balance between workability and mechanical strength, which may be considered a technically viable alternative for structural repair mortars.

Instituciones: Universidad Nacional de Ingeniería; Universidad Continental