Fresh and hardened state properties of fiber reinforced lime-based grouts

Abstract

In this study, an effort has been made, to envisage the performance of fiber-reinforced lime-based grouts, both in fresh and hardened state. Two grout series were manufactured and tested regarding lime: natural pozzolan (1:1) and NHL3.5. Glass fibers of different length (3 mm and 6 mm) were used, in a proportion of 0.1 and 0.3% w/w of binders, as well as 6 mm polypropylene fibers in a proportion of 0.1% w/w. The grout mixtures were tested both in fresh and hardened state. From the correlation of the results, it was firstly asserted that the mixing procedure followed in the case of fiber-reinforced grouts is of great importance. The fresh state properties of the grouts were slightly affected by the fibers’ addition and properties were maintained at acceptable level. However, the W/B ratio of the mixtures was slightly increased by the fibers’ addition, influencing their physical characteristics. Porosity was slightly increased while apparent specific gravity, as well as water absorption coefficient due to capillary action slightly decreased. Regarding mechanical properties, the addition of fibers (mainly those of 6 mm length and in a proportion of 0.3% w/w of binders) enhanced the long-term strength, as well as the adhesive capability of grouts. In the lime:pozzolan matrix, compressive strength was significantly increased, especially in the case of glass and polypropylene fibers. In any case, the addition of selected fibers in lime-based grouts seems to be a well-promising research field that needs to be further studied.