Rheological and Mechanical Response Modifications for a Self-Leveling Mortar

Abstract

Abstract. In many cases cement based materials demand a higher flowability and workability and this conventionally can't be done without loss of its strength, due to the fact that the common practice to increase the workability is the addition of water. But, nowadays using a third generation superplasticizer (SP) we can achieve the desire flowability without loss of its strength. The action of superplastisizers is to spread efficiently the cement grains and so to wetting better the cement grains giving a more homogeneous mixture with higher strength. Nine different mixtures were prepared adding a small percentage of SP (1%). The conditions to get a self levelling mortar, have to do not only with rheological but also with mechanical demands. The bending and compression test gave the achieving mechanical strength whereas their rheological response came through slump flow and v-funnel flow tests. With the help of a small amount of stabilizer we obtain a robust mixture that deserves the desire response at the field too.

Reação Sulfática Interna (RSI) como degradação de matriz cimentícia: comportamento de pastas dosadas com diferentes teores de contaminação por sulfato

“…Observing Figure 1 it is possible to see that the spread was decreasing with the increase of the addition of contaminating material. This is according to what was exposed by Katsiadramis et al (2010), because materials of greater granulometry, in this case pyrite (Dmax equal to 2.4mm), act as obstacles, increasing the viscosity of the compound. This is contrary to the fine grains, in this case the filler, which act as lubricants increasing the fluidity of the material.…”

Fresh and Hardened Properties of Self‐Leveling Mortars with Porcelain and Red Ceramic Wastes

“…All results obtained to porcelain waste mortars were higher than those of the reference mortar. While the reference mortar had a capillary absorption result of 3.50 g/cm 2 in 24 hours, the mortar with waste had capillary water absorption results in the range of 5.70 g/cm 2 to 14.3 g/cm 2 . e highest capillary water absorption value was to C50 (1.43 g/cm 2 ) and the lowest was to reference.…”

“…e specimens were weighted at different time intervals of 5, 10, and 30 minutes at 1, 2, 4, 6, 8, and 24 hours. Capillary water absorption was calculated according to (2). e absorption test results are presented as the quantity of water absorbed per unit area (kg/m 2 ) versus the square root of time:…”

“…In Brazil, the use of self-leveling mortar is not a common practice, and a small number of companies market this material in bags or produce it in plants to apply it directly on the construction site by pumping. e SLM as any other cement-based material has the inverse relationship between workability and mechanical strength [2], and it is difficult to obtain fluidity without bleeding and/or segregation. Since this material often requires high water/cement ratios, it is necessary to obtain a material with self-leveling characteristics without bleeding and/or segregation and also with good mechanical properties.…”

Influence of the physical characteristics of sand and the crushed filler content on the properties of self-leveling mortars

“…In addition, the dimensions of the sand grains should also be studied. According to Katsiadramis et al [13], coarse aggregates act as obstacles in self-leveling systems, while fine aggregates favor fluidity. The influence of coarse particles is related to the difficulty of movement between them, resulting from the existence of a coefficient of friction between these particles, hindering the fluidity.…”