Title: Study of Environmentally Friendly Mortars Prepared with Recycled Concrete Aggregates and Biomass Ash

Author(s): Valeria Corinaldesi, Jacopo Donnini, and Glauco Merlonetti

Publication: Symposium Paper

Volume: 326

Issue:

Appears on pages(s): 53.1-53.10

Keywords: biomass ash; bond strength; concrete recycling; C&D waste; environmentally-friendly mortars; recycled aggregate mortar; sustainability

DOI: 10.14359/51711036

Date: 8/10/2018

Abstract:

This work studied the possibility of reusing waste from demolished concrete as aggregate for bedding mortars as well as biomass ash coming from paper mill sludge as partial cement replacement.

During incineration of paper mill sludge, paper and organic compounds are burned out, whereas mineral fillers and inorganic salts are trans-formed into the corresponding oxides at higher temperatures. The obtained paper mill sludge ash is classified as waste, and at present it is mainly conferred to landfill at high costs.

In order to evaluate the quality of joining mortars made of recycled aggregate and biomass ash, both mechanical behavior of mortars and the bond strength developed at the interface mortar–brick were studied. The experimental results show that mortars containing recycled aggregates develop lower mechanical strength with respect to the reference cementitious mortar, particularly when recycled aggregates and biomass ash are used together. Nevertheless, the bond strength at the interface between the mortar and the brick resulted higher if an inorganic primer is used. However, concerning bedding mortars, the mechanical performance of the overall mortar–brick system, strictly related to the mortar–brick adhesion, makes the mortar bond strength certainly more important than its mechanical strength.