Mineralogical and chemical characterization of CDW as function of particle size and thermal treatments for potential recycling

Construction and Demolition Waste (CDW) originating from the rubble produced by the 2016 seismic events in the Marche Region (Central Italy) has been studied, focusing on its mineralogical and chemical characteristics, to investigate its recycling potentials as a component for eco-sustainable building material or in the glass industry. The aim was to obtain a full characterization of the behaviour of this material at high T in order to determine the most advantageous conditions for vitrification, considered as an effective process for volume reduction as well as for immobilization of potentially hazardous elements. Vitrification experiments, carried out with thermal treatments as function of temperature/duration/particle size and aimed at amorphization, were carried out under atmospheric conditions, at different temperatures (1000-1250°C) and durations (2-8 hours). The study demonstrated that mineralogical composition remains homogeneous for grainsize <4 mm, thus suggesting that no sieving is necessary for recycling of the fine fractions, which are the most difficult to treat. Vitrification, although not achieved for the CDW sample up to 1250°C, due to high-Ca and low-Si contents, demonstrated that this CDW can produce an interesting refractory material and a porous/insulating material. However, experiments showed that full vitrification can be easily achieved by mixing urban waste glass and CDW, suggesting applications in the glass industry. Based on the chemical and mineralogical features of the products, other significant upgrading alternatives of recycling the CDW in different fields of applications are highlighted.

Download Full-text

Dimensional, Mechanical and LCA Characterization of Terrazzo Tiles along with Glass and Construction and Demolition Waste (CDW)

10.21926/rpm.2101006 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Paola Stabile ◽

Francesco Radica ◽

Luigi Ranza ◽

Michael R. Carroll ◽

Carlo Santulli ◽

...

Keyword(s):

Double Layer ◽

Mechanical Performance ◽

Raw Materials ◽

Central Italy ◽

Single Layer ◽

Resource Depletion ◽

Construction And Demolition Waste ◽

Demolition Waste ◽

Aesthetic Aspect

In this work, two types of wastes were introduced, namely, glass from municipal waste and Construction and Demolition Waste (CDW). The latter, which was obtained from rubble generated by the seismic events occurred in Central Italy in 2016, was introduced in two configurations, the single-layer and the double-layer of the cement-based Terrazzo tiles. A maximum of 77% of waste introduction was proven to be possible, therefore creating the possibility of obtaining construction products including high quantities of secondary raw materials, coupled with a valuable aesthetic aspect. The tiles represent a novel CDW upcycling application and follow the EU recommendations to improve the circular economy in the building sector. In particular, the products obtained showed dimensional conformity in the specifications and mechanical performance in the case of double-layer tiles as required by the envisaged use in the flooring (EN 13748-1). A life cycle analysis (LCA) clarified the possible advantages in terms of reduced resource depletion (RD) and global warming potential (GWP). The evaluation at the aggregate/glass matrix interface indicated good performance of the tiles, demonstrating the readiness for industrial production and market introduction.

Download Full-text

A New Low-Cost and Reliable Method to Evaluate the Release of Hg0 from Synthetic Materials

Processes ◽

10.3390/pr8101282 ◽

2020 ◽

Vol 8 (10) ◽

pp. 1282

Author(s):

Marta Lazzaroni ◽

Barbara Nisi ◽

Daniele Rappuoli ◽

Jacopo Cabassi ◽

Orlando Vaselli

Keyword(s):

Low Cost ◽

Central Italy ◽

Elemental Mercury ◽

Blocking Agent ◽

Construction And Demolition Waste ◽

Concrete Wall ◽

Demolition Waste ◽

Mining Site ◽

Gaseous Elemental Mercury ◽

Synthetic Materials

Mercury is a toxic and noxious element and is the only metal that naturally occurs as gas. One of the most challenging topics (included in the United Nations Minimata convention) is to understand the adsorption–release processes of manmade materials (e.g., concrete, bricks, tiles, painting). Adsorption of Hg by construction and demolition waste materials has recently been studied, but investigations on how much Hg0 can be released from these products are rather poor. The abandoned mining site of Abbadia San Salvatore (Siena, central Italy) where, for about one century, cinnabar was roasted to produce liquid mercury, is known for the high concentrations of (i) Hg0 in edifices and structures and (ii) total and leachate Hg in synthetic materials. In the present paper, a new, simple and low-cost method to measure the amount of GEM (Gaseous Elemental Mercury) released from anthropic materials (concrete, wall rocks, and tiles) located in the Hg0-rich environments of the former mining site, is proposed. The efficiency of a specific paint that was supposed to act as blocking agent to Hg0 was also tested.

Download Full-text

Microstructural and Thermo-Physical Characterization of a Water Hyacinth Petiole for Thermal Insulation Particle Board Manufacture

Materials ◽

10.3390/ma12040560 ◽

2019 ◽

Vol 12 (4) ◽

pp. 560 ◽

Cited By ~ 5

Author(s):

Adela Salas-Ruiz ◽

María del Mar Barbero-Barrera ◽

Trinidad Ruiz-Téllez

Keyword(s):

Particle Size ◽

Thermal Insulation ◽

Water Hyacinth ◽

Eichhornia Crassipes ◽

Construction Material ◽

Chemical Characterization ◽

Thermal Characterization ◽

Particle Board ◽

Global Concern

Water Hyacinth (Eichhornia crassipes) is a dangerous and invasive aquatic species, of which global concern has sharply risen due to its rapid growth. Despite ample research on its possible applications in the construction field, there are no clear references on the optimal use of the plant in finding the most efficient-use building material. In this paper, a microstructural and chemical characterization of the Water Hyacinth petiole was performed, in order to find the most efficient use as a construction material. Subsequently, two types of binder-less insulation panels were developed, with two types of particle size (pulp and staple). A physical, mechanical, and thermal characterization of the boards was performed. These results demonstrated that it is possible to manufacture self-supporting Water Hyacinth petiole panels without an artificial polymer matrix for thermal insulation. The boards showed good thermal conductivity values, ranging from 0.047–0.065 W/mK. In addition, clear differences were found in the properties of the boards, depending on the type of Water Hyacinth petiole particle size, due to the differences in the microstructure.

Download Full-text