Abstract
This study investigates the effects of the content and dispersion of limestone fine particles on the bond strength of mortar-brick interfaces. Mortars with 0%, 30% and 60% replacement of binder by limestone fines with a particle size distribution lower than cement. We also evaluated particle dispersion by adding 0.02% polycarboxylate-based dispersing admixture to the mortars applied on the surfaces of clay bricks treated with a water repellent. The rheological behavior of the mortars varied depending on the particle size of the limestone fines used and the admixture added, measured by a rotational rheometer. Despite a reduction in the mechanical properties, the 60% replacement of of binder by limestone fines, associated with the use of dispersing admixture can increase the bond strength of the mortar-brick interface by 76%. The increased adherence can be explained by the increased area or contact between substrate and mortar. The conclusion has practical implications, as it demonstrates that is possible to reduce the amount of matrix binder without changing bond strength.
Keywords:
Bond strength; Limestone fine; Mortar; Substrate; Dispersing; Binder
Fonte:
Nota: as partículas não preenchem todas as irregularidades da superfície do substrato.
Nota: há aumento do contato efetivo com o uso de FC1, porém a topografia do substrato ainda não é toda recoberta, tornando-se necessária a inclusão de partículas mais finas.
