CeraMat

The aim of this research is to produce self-healing cementitious composites based on the use of cylindrical capsules containing a repairing agent. Cementitious hollow tubes (CHT) having two different internal diameters (of 2 mm and 7.5 mm) were produced by extrusion and used as containers and releasing devices for cement paste/mortar healing agents. Based on the results of preliminary mechanical tests, sodium silicate was selected as the healing agent.

In the present work, carbon nano/micro-particles obtained by chemical vapor depostion (CVD) process and controlled pyrolysis from polyethylene beads (CNBs) and coconuts choir (CCNs) are presented. These materials were characterized by Raman spectroscopy, thermogravimetry and field emission-scanning electron microscopy (FE-SEM). FE-SEM observations evidenced that CNBs particles proved to be spherical and interconnected, while the CCNs were irregular in shape, as the result of the grinding step.

WO3 and WO3-based materials in the form of thin films, either as bulk or as nanostructures, have been widely used for the detection of a variety of gases, such as NO2, H2, NH3 and Cl2. The purpose of this study was to prepare materials from the WO3-ZnO-Nd2O3-Al2O3 system containing high amount of WO3 for applications in environmental monitoring by applying the melt quenching method. Homogenized batches of the starting oxides were melted for 20 min at 1,240 °C in platinum crucibles in air atmosphere.

n the production of coarse recycled aggregates (RA), the fine fraction is involuntarily produced, representing a large amount of the weight of the crushed C&D waste. In this work the mortar has been analyzed, by replacing standardized sand (SS) with recycled sand (RS) and by using a fixed w/c ratio equal to 0,5. The most relevant problem has been occurred during the mixing phase: in fact, RS induced a high water demand which made the mechanical properties worst.

A novel cost-effective alternative in the form of nano/micro carbonized particles produced from waste bagasse fibers has been explored to modify the mechanical properties and fracture pattern of the resulting cementitious composites. Carbonized bagasse particles were produced at Politecnico di Torino and characterized by Raman spectroscopy and scanning electron microscopy. When added with cement paste up to 1 wt% in six different proportions, the carbonized bagasse particles were found effective in significant enhancement of mechanical strength as well as fracture toughness.

The current study is focused to explore a cost effective material for enhancing the electromagnetic interference shielding effectiveness of cement composites. Agricultural residue in the form of peanut and hazelnut shells having little or no economic value was investigated for the subject purpose. These wastes were pyrolyzed at 850 C under inert atmosphere and ground to sub-micron-size before utilization with cement. Dispersion of sub-micron-carbonized shell was initially observed in water through visual inspection and later in cement matrix using FESEM micrographs of fractured composites.

Nanotechnology has revolutionized every field of science by opening new horizons in production and manufacturing. In construction materials, especially in cement and concrete, the use of nano/microparticles and fibers has opened new ways from improved mechanical properties to enhanced functionalities. Generally, the production or manufacturing processes of nano/micro-sized particles are energy intensive and expensive.

There is a tremendous increase in the use of high strength and high performance self-consolidating cementitious composites due to their superior workability and mechanical strengths. Cement composites are quasi-brittle in nature and possess extremely low tensile strength as compared to their compressive strength. Due to the low tensile strength capacity, cracks develop in cementitious composites due to the drying shrinkage, plastic settlements and/or stress concentrations (due to external restrains and/or applied stresses) etc.