The rapid growth of the marble industry introduces concerns regarding the negative impact of marble quarrying on the environment, because the cutting of marble creates sludge. The incorporation of marble sludge (powder) into concrete and cement-based products would make significant environmental and economic contributions. This study aims to develop a concrete mixture with maximum marble content that has strength properties comparable to that of the non-marble reference concrete (without marble powder), as opposed to developing a marble powder concrete with maximum compressive strength. The main purpose is to replace sand with marble powder in concrete because such a mixture will be environmentally friendly and economically feasible. The concrete samples are produced by replacing sand with marble powder at 10%, 20%, 30%, 40%, 50% and 90% by volume. The compressive strength values are determined after 7, 28 and 90 days with splitting tensile strength values at 28-th day including water absorption and abrasion resistance values. A feasibility evaluation is performed using parameters such as fresh concrete, compressive strength, sorptivity, abrasion resistance, and estimated cost. Based on the feasibility evaluation it is shown that using up to 40% marble powder in concrete is suitable in accordance with the requirements.

Due to the need for high-performance and sustainable building materials, the investigation of the determination of fracture toughness of cement paste using new and sustainable materials, such as cellulose nanocrystals (CNCs) is worthwhile. Contrary to other well-known nano-reinforcement particles, such as carbon nanotubes, CNCs are less toxic; therefore, they have less safety and environmental risks. Fracture behavior of cement paste has been studied intensively for a long time. However, the incorporation of new materials in the cement paste, such as cellulose nanocrystal materials (CNCs), has not been fully investigated. In this paper, the fracture behavior, compressive strength, and hydration properties of cement paste reinforced with cellulose nanocrystal particles were studied. At the age of 3, 7, and 28 days, a three-point bending moment test, and a calorimetry and thermogravimetric analysis, scanning electron microscopy (SEM), and energy dispersive x-ray spectroscopy (EDX) analysis were performed on the water-to-binder-weight ratio of 0.35 cement paste, containing 0.0%, 0.2%, and 1.0% volume cellulose nanocrystals. Results indicated that the fracture properties and compressive strength were improved for the sample containing 0.2% CNCs. Preliminary results indicate that CNCs can improve the fracture behavior of cementitious materials and can be considered as a renewable and sustainable material in construction.