Properties of Cement and Mortar Incorporating Marble Dust and Crushed Brick

Blended cements based on the partial replacement of Portland cement clinker (PC) by wastes have been the subject of many investigations in recent years. The use of the replacement materials offer cost reduction, energy savings, arguably superior products, and fewer hazards in the environment. These materials participate in the hydraulic reactions, contributing significantly to the composition and microstructure of hydrated product [1-7]. The CB is among the waste materials. The raw materials used in the manufacture of bricks are mainly natural clays containing quartz, and feldspar. Bricks are manufactured by the calcination of alumino-slicate clays. Heating destroys the crystal structure of the clays, which results in amorphous or disordered alumino silicate structure. Amorphous substances react with lime to produce calcium silicate hydrate and/or calcium aluminate hydrate at the brick-lime interface. It has been shown that the calcination temperature of clay has significant effect on the pozzolanic activity depending on the type of the clay mineral [8]. For kaolinite clay, heat treatment converts kaolinite clay (weakly pozzolanic) to metakaolin (highly pozzolanic) at 700-800°C. Although, at temperatures over 800°C, pozzolanic activities of metakaolin are lost due to the formation of high temperatures minerals, some pozzolans such as pulverized-fuel ash (PFA), pozzolanic component, which is amorphous glass phase, occurs above 1000°C. Studies have shown that a clay brick heated at around 1000°C gives maximum pozzolanic activity when incorporated into cementitious materials [9]. Depending on the type of the CB, it alters the pore size distribution, threshold radius, and compressive strength of the mortars [10]. It also increases the resistance of the mortar to sulfate attack and expansion [11, 12]. Despite growing attempt of using CB as cement constituent, little attention has been paid on the study of MD behavior when it is co-ground with clinker and gypsum to produce blended cement. Large quantities of MD are produced annually in Turkey. The MD is generated as a by-product during the cutting of marble. During the cutting process, about 25 % marble is resulted in dust. The marble cutting industries are dumping the MD in any nearby pit or vacant spaces. This imposes threats to eco-system, and physical, chemical and biological components of the environment. Therefore, utilization of MD in the production of new materials will help to protect environment. Recently the use of MD as replacement materials has been investigated. Agarwal and Gulati [13] demonstrated that the presence of MD in the matrix enhances the early compressive strength of the mortar, and the strength of the mortar decreases with the increasing MD content. According to authors, both of the early and long-term strength of the mortar can be improved by the inclusion of slag and fly ash in the matrix. Original papers