Preliminary Study of the Mechanical Behavior of Gypsum Plastering Mortars with Ceramic Waste Additions

Abstract

In recent years, the construction sector has generated large amounts of construction and demolition waste (CDW). In Europe, more than 50% of this waste is ceramic waste (CW). Therefore, and in accordance with the Circular Economy Action Plan, the building sector should reintroduce a certain amount of CDW into the life cycle of buildings. Many studies have sought to incorporate CDW in gypsum plaster and cement mortars for construction. However, few studies have analyzed the feasibility of replacing raw materials such as gypsum, cement, or sand with CW. A three-phase experimental plan was designed to introduce various types of CW—from new construction and from rehabilitation works—in a gypsum matrix. The viability of the new mortar and its capacity to improve the mechanical and physical properties of gypsum without additions were analyzed. In the first phase of the experimental plan, CW was added in different percentages and granulometries into the gypsum matrix to make different mortars samples, and mechanical tests were conducted. The plaster mortar with the best results for use as coating was selected. The following tests, considering the final application of the mortar, were carried out: setting time, water capillarity absorption, and adherence. A chemical and mineralogical characterization was performed on the CW. The results showed that it is feasible to replace part of the raw gypsum material with recycled ceramic material. The superficial hardness, water absorption, adhesion, and mechanical resistances of the gypsum mortars containing CW were improved compared with those of gypsums without additions.