Cementitious eco-composites and their physicochemical/mechanical properties in Portland cement-based mortars with a lightweight aggregate manufactured by upcycling waste by-products

This article presents testings' results of cement composites with Composite Lightweight Aggregates (CLAs) as a partial substitute of natural aggregates. A new sustainable eco-composite manufacturing took place in laboratory conditions by using 100% waste by-products: PET flakes and sewage sludge fly ash (ssFA) streams or siliceous fly ash (FA). The manufactured (EN 196-1) modified cement mortars were tested in a various series of CLAs by applying volume replacements of 10% and 25% regarding the standard aggregate. The new insights on physical-chemical properties of the original materials and effective water and mechanical performance of both the fresh and hardened specimens contrasted the qualitative and quantitative assessments in the function of the two different aggregates production methods lines. Frattini test is also used to assess the impact of the aggregate composite on the cement composite and their mutual interactions. The obtained results show that the use of CLA as a substitute of standard aggregate allows reducing the water content in the mix while maintaining good workability and increasing compressive and flexural strengths up to 25% of reference mortar. (c) 2020 Elsevier Ltd. All rights reserved.