Per: MARKSSUEL TEIXEIRA MARVILA (UFV - CRP), Douglas Maxwel Carneiro Caixeta (UFV - CRP), Marília Gonçalves Marques (UFV - CRP), Leonardo Carvalho Mesquita (UFV - CRP), Afonso Rangel Garcez de Azevedo (UENF)
Abstract:
Mortars based on Portland cement and hydrated lime are widely used in civil construction for covering and laying walls, for example. However, the binders used in the production of mortars are produced in a way that is harmful to the environment, highlighting the need for alternative binders. In this work, the use of kaolinite plastic sand in mortars was evaluated, replacing hydrated lime at levels of 0%, 50% and 100%. Properties were evaluated in the fresh state, such as consistency and squeeze flow; in addition to properties in the hardened state, such as compressive strength, water absorption, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Workability tests show that kaolinite plastic sand has the potential to improve mortar workability. In dynamic tests (consistency) it was observed that the 100% kaolinite plastic sand composition is viable as it promotes an increase in spreading from 253 to 265 mm. In static tests (squeeze flow) the composition with 50% kaolinite plastic sand showed the best spreading results, with values of 10.7 mm, while the compositions containing 0% and 100% showed spreading of 8.97 and 7.40 mm, respectively. This demonstrates the potential of using kaolinite plastic sand in mortars. The hardened state results, such as compressive strength and water absorption, were also satisfactory. Finally, it was observed from the XRD and SEM results that the kaolinite plastic sand shows adhesion with the Portland cement hydration products in the mortar, promoting a reduction in ettringite and portlandite due to its moderate pozzolanicity. Based on these results, it is possible to conclude that kaolinite plastic sand is a viable substitute for hydrated lime in mortars
