Concrete production consumes enormous amounts of fossil fuels, raw materials, and is energy intensive. Therefore, scientific research is being conducted worldwide regarding the possibility of using by-products in the production of concrete. The objective is not only to identify substitutes for cement clinker, but also to identify materials that can be used as aggregate in mortar and concrete productions. Among the potential alternative materials that can be used in cement composite production is rock dust of different geological origin. However, some adversarial effects may be encountered when using rock dust regarding the properties and durability of mortars and concrete. Therefore, comprehensive research is needed to evaluate the adequacy of rock dust use in cementitious composite production. This paper presents a comprehensive review of the scientific findings from past studies concerning the use of various geological origins of rock dust in the production of mortars and concrete. The influence of rock dust as a replacement of fine aggregates on cementitious composites was analyzed and evaluated. In this assessment and review, fresh concrete and mortar properties, i.e., workability, segregation, and bleeding, mechanical properties, and the durability of hardened concrete and mortar were considered.

As an alternative to ordinary Portland cement (OPC), alkali‐activated materials (AAMs) have more recently been studied and found to have certain suitability in reducing ecological footprint of OPC binding systems. Nonetheless, due to recent concerns over the availability of certain precursors used AAMs (such as the reduction of coal fly ash availability), this study utilized marble powder in various quantities to replace the naturally available kaolin as precursor. This composite use of natural precursors has been entertained to assimilate the production of carbon zero AAMs. To evaluate the physico‐mechanical and microstructural characteristics of the materials, 48 mixes with different sodium (Na) concentrations, curing temperatures, and marble powder content have been used. The results show that rising curing temperature is more effective than other variables, such as the Na and marble powder content on the physico‐mechanical performance of tested geopolymers. In this regard, it is found that a very high Na content can have adverse effect on the properties, potentially due to altered Na/Si, Na/Al ratio in the mixes. Furthermore, the inclusion of marble powder is found to be effective in decreasing the overall porosity up to ~31% and enhancing the physico‐mechanical properties of the specimens cured at 20 and 80°C. Nonetheless, results show that when specimens containing marble powder are exposed to higher curing temperatures (above 80°C) the presence of marble powder adversely affects physico‐mechanical properties. It is concluded that this phenomenon is caused by the dehydration of chemically bound water in higher temperatures when marble powder is used. This result is further confirmed by microstructural tests.

The greatest weakness of concrete as a construction material is its brittleness and low fracture energy absorption capacity until failure occurs. In order to improve concrete strength and durability, silica fume SF is introduced into the mixture, which at the same time leads to an increase in the brittleness of concrete. To improve the ductility and toughness of concrete, short steel fibers have been incorporated into concrete. Steel fibers and silica fume are jointly preferred for concrete design in order to obtain concrete with high strength and ductility. It is well-known that silica fume content and fiber properties, such as aspect ratio and volume ratio, directly affect the properties of SFRCs. The mixture design of steel-fiber-reinforced concrete (SFRC) with SF addition is a very important issue in terms of economy and performance. In this study, an experimental design was used to study the toughness and splitting tensile strength of SFRC with the response surface method (RSM). The models established by the RSM were used to optimize the design of SFRC in terms of the usage of optimal silica fume content, and optimal steel fiber volume and aspect ratio. Optimum silica fume content and fiber volume ratio values were determined using the D-optimal design method so that the steel fiber volume ratio was at the minimum and the bending toughness and splitting tensile strength were at the maximum. The amount of silica fume used as a cement replacement, aspect ratio, and volume fraction of steel fiber were chosen as independent variables in the experiment. Experimentally obtained mechanical properties of SFRC such as compression, bending, splitting, modulus of elasticity, toughness, and the toughness index were the dependent variables. A good correlation was observed between the dependent and independent variables included in the model. As a result of the optimization, optimum steel fiber volume was determined as 0.70% and silica fume content was determined as 15% for both aspect ratios.