Estudo da resistência de aderência de argamassas com substituição parcial de Cimento Portland por sílica da casca de arroz em prismas de tijolos maciços

Abstract

In this work, the flexural tensile strength and the axial compression strength was analyzed with mortars prepared with high percentage of Rice Husk Silica tested according to NBR 13279. In the mortars, was used to replace 5% and 30% by mass of cement. Was also analyzed of performance to bond strength through the shear test using pre-compression of molded prisms with the mortars contents replacements when applied at different times (15, 60 and 180 minutes). In the results found for the performances to axial compression and bending in three points, the substitution in the values of 5% did not significantly alter the strength of the mortars in relation to indirect traction and compression. In addition, the replacement in values of 30% of rice husk silica at the age of 28 days presented values lower than the reference values for the three-point bending and axial compression tests. On the other hand, in the shear strength test of solid brick prisms, the replacement of 30% of rice husk silica showed the best strengths when applied in times of up to 60 minutes. The mortars without addition and with 5% replacement did not present significant differences in relation to the performance of this replacement and demonstrated that they can be applied at any time without considerable loss of performance in the shear tests. Key-Words: Adherence; Cement Replacement; Mortars; Rice Husk Silica; Shear Test of Prisms.