A Comparative Study on Opto-Thermal Properties of Natural Clay Bricks Incorporating Dredged Sediments

Abstract

The brick industry is currently facing a shortage of natural resources. Despite this, the demand for construction bricks is progressively increasing. Alternative materials, such as dredged sediments and solid organic waste, have been recently proposed as options to replace natural clay in brick manufacturing. Potential exploitation of dredged sediments in clay bricks is evaluated in this study. The chemical composition of the mixtures and the opto-thermal properties of brick samples, which differed for the dredged sediment content (from 10% to 50% of the clay weight), were investigated. Chemical analyses detected lower concentrations of heavy metals in bricks incorporating dredged sediments (DS). Negligible variations in thermal conductivity, thermal diffusivity, and specific heat were observed by increasing the amount of DS in the mixture. In particular, the thermal conductivity values ranged between 0.45 ± 0.03 W m−1 K−1 (DS-50) and 0.50 ± 0.03 W m−1 K−1 (DS-30). Conversely, the color shift value and spectral reflectance in the infrared field were found directly proportional to the concentration of DS. Using dredged sediments as building material demonstrated to be a solution to the problem of their disposal and the scarcity of raw materials, reducing the global warming score by up to 2.8%.