Compressive strength assessment bricks manufactured with Phosphogypsum in different dosages

Abstract

This research studies soil-compacted bricks using Phosphogypsum (PG) in their dosage. PG is the subproduct of the primary raw material used by the fertilizer industry, and its disposal is a challenge for the industry because of its large generation. Laboratory tests were performed to assess these bricks' physical characteristics. To obtain the bricks, two dosages were used: 4 and 7% of Phosphogypsum (PG) concentration. Bricks with no Phosphogypsum (PG) in their mixture were also assessed as a benchmark. The brick's physical characteristics were obtained for non-fired and fired bricks (900ºC for 96 hours in the oven). The results of the laboratory tests were analyzed through statistical analysis to explore the differences between the means for each studied condition (dosage and drying method). Furthermore, there was no statistical difference between the compressive strength of bricks manufactured with 4 and 0% PG, pointing out that until this percentage, the studied bricks did not show strength reduction with PG increasing. The fired bricks showed higher strength for all dosages than the non-fired ones. However, according to the Brazilian Technical Standards, all studied bricks presented enough strength for regular construction. Phosphogypsum (PG) for brick manufacturing can be an alternative way for its disposal, which can help mitigate the civil construction environmental impacts.