Impact of polypropylene microfibers on the toughness and ductility of self-compacting soil-cement

ABSTRACT

Soil-cement depends on improving its characteristics to suitable performance as a built environment. In view of this, this study started with self-compacting soil-cement with a superplasticizer additive and polypropylene microfibers (SCSCF) to analyze the influence of these additions on the composite's brittle behavior. To this end, SCSCF mixtures with potential for use in wall construction were selected and the axial strength, 4-point flexion and dimensional variation by drying tests were applied. The results showed that the addition of microfiber to the SCSCF increased the incorporation of air into the system, decreased the apparent dry mass and was ineffective in controlling linear shrinkage during drying. Consequently, it negatively affected the strength to axial and flexion; and ductility was harmed by the low anchoring capacity of the cement matrix to the fibers. However, the use of microfiber for the post-cracking state of the SCSCF was relevant, as it increased the toughness and reduced the fragility of the composite. The SCSCF was characterized as an isotropic material, with launch and conformation capacity suitable for use in monolithic walls without the need for densification, reaching at 28 days of age axial and flexion strength values, respectively, in the order of 4.5 MPa and 1.4 MPa.

Keywords:
Construction with earth; Fluidity; Bending; Shrinkage