One of the critical environmental issues in the Chegeni area (Lorestan Province, western Iran) is the production of a large volume of limestone wastes during the quarrying operations. Releasing limestone wastes in the areas neighboring the quarries has caused visual damage to the environment, and adverse effects on the quality of the soil, running water, and groundwater used for agricultural and drinking water purposes. One solution to this issue can be recycling limestone wastes to produce building materials. In the present study, a comprehensive laboratory program is planned for the durability evaluation of the limestone wastes under harsh environments for their suitability as aggregate in concrete. For this purpose, five aging tests, including freezethawing (F-T), salt crystallization (SC), acid attack (AA), wetting-drying (WD), and heatingcooling (HC), were conducted on the limestone sample up to 60 cycles. After every 10 cycles, the physico-mechanical characteristics of the sample, including porosity (n), Brazilian tensile strength (BTS), point load index (PLI), and P-wave velocity (Vp) were determined. Moreover, the pores structure modification of the sample subjected to aging tests was examined through scanning electron microscopy (SEM). Data analyses revealed that the sample is highly vulnerable to the AA and SC processes but is durable against FT, WD, and HC actions. These results were in good agreement with the SEM data such that the sample exposed to AA and SC underwent more changes in their pore structure compared to FT, WD, and HC. Among the physico-mechanical characteristics, the Vp and PLI had the highest and the lowest accuracy, respectively, in the durability evaluation of the sample exposed to aging tests. Based on the data analysis, limestone wastes can be used as aggregate in concrete in environments with the possibility of FT, WD, and HC. However, this type of concrete is not suitable for conditions with occurrences of the AA and SC. Finally, in addition to reducing the environmentally harmful impacts of the study area, using limestone wastes as aggregate in the construction of concrete can also be a practical solution for sustainable development from an economic viewpoint. The results of the present study can be used for assessing limestone wastes produced in other areas of Iran and the world.

Loess, a terrestrial clastic sediment, is formed essentially by the accumulation of wind-blown dust, while stone waste (SW) is an industrial waste produced during stone machining. Utilising loess and SW to prepare environmentally-friendly supplementary cementitious materials can not only address environmental issues caused by solid waste landfills but also meet the demand of reinforcement of coal-seam floor aquifer for grouting materials. In this paper, the effects of the loess/SW mass ratio and calcination temperature on the transformation of calcined products are investigated and their pozzolanic activities are evaluated. The workability, environmental impact and cost of grouting materials based on cement and calcined products are also assessed. Experimental results reveal that higher temperatures favour the formation of free lime and periclase, which tend to be involved in solid-state reactions. Higher temperature and loess/SW mass ratio strengthens the diffraction peaks of dodecalcium hepta-aluminate (C12A7), dicalcium ferrite (C2F) and dicalcium silicate (C2S). The clay minerals in loess become completely dehydroxylated before 825 degrees C, generating amorphous SiO2 and Al2O3. Covalent Si-O bonds are interrupted and that disordered silicate networks are generated in the calcined products, which is confirmed by the increased strength of the Si29 resonance region at -60 ppm to -80 ppm. Although co-calcined loess and SW contain the most four-fold aluminium at 950 degrees C, recrystallisation depresses the pozzolanic activity. Hence, the loess/SW sample designated LS2-825 exhibits the better hydration activity. Additionally, grouting materials composed of cement and LS2-825 exhibit good setting times, fluidity, strength and a low carbon footprint in practical engineering applications, and they also provide the additional benefit of being cost effective.