Evaluation of mechanical properties of grouts substituting the natural coarse aggregate for ceramic civil construction waste

Résumé

The lack of control regarding waste generation is a problem still faced by the construction industry, whereas its inputs could be used in the production of new cementitious composites, maintaining the quality, performance and sustainability of structures. This study developed grouts through the substitution of natural aggregate for residues of crushed ceramic bricks, evaluating its fresh state and mechanical properties. The samples displayed loss of workability and initial slump in fresh state, besides loss of compressive strength, elastic modulus, total water absorption and capillary water absorption in hardened state. In addition, composites with grog presented less consistency in fresh state when compared to the reference sample. The differences were even greater over time. As for the hardened state, the compressive strength of the samples was similar among them at both ages, and all results remained above 14 MPa at 28 days, as required by ASTM C476, hence being characterized as structural grouts for masonry. For the elastic modulus test, the results were higher for samples with lower amounts of waste due to less internal voids and higher volume of natural aggregates. The substitution of natural aggregate for civil construction waste (CCW) in the mixtures increased void ratio and water absorption, while causing the lowest specific gravities of the research. Overall, the sample that presented the most satisfactory values was CCW 25%, showing that it is possible to obtain benefits from waste produced in factories and buildings, even for higher replacement levels, occasionally. Keywords: ceramic waste; grouts; mechanical properties; physical properties; durability.