## 1 Introduction
[10] used nano-silica (NS) and slag to manufacture sustainable HSC. For this aim, 2% of cement was replaced with NS, and slag was utilized at four replacement ratios of 25%, 50%, 75% and 100% instead of sand. It was shown that increasing the value of NS and slag led to improving the strength and durability of concrete; however, workability dropped. In another research, [PERSON] and [PERSON] [11] evaluated the influence of NS and coir fibre on the mechanical performance of concrete. Therefore, fibres were utilized at 0.25%, 0.5%, and 0.75% by weight of fine aggregates and 2% and 3% NS with 15% fly ash replaced cement. According to the results, the optimal contents of fibres and NS in terms of abrasion resistance were 0.25% and 3%, respectively. In 2018, [PERSON] et al. [12] considered the influence of NS, super absorbent polymers and synthetic fibres on the shrinkage cracking of concrete. It was shown that the use of NS in concrete should be carefully examined. Moreover, using both NS and super absorbent polymers considerably improved the shrinkage cracking. [PERSON] et al. [13] employed NS to improve the corrosion resistance of recycled aggregate concrete. Therefore, both the fresh and hardened state properties of concrete were examined. The improvement of the corrosion resistance of concrete when NS was utilized was the main conclusion of this study. [PERSON] et al. [14] used NS and fly ash to improve the mechanical characteristics and chemical durability of geopolymer concrete. Four types of geopolymer and ordinary concrete mixes were subjected to sulphuric acid, magnesium sulphate and seawater solutions with concentrations of 5%, 5% and 3.5%, respectively. To evaluate the mechanical performance of the specimens, compressive, splitting tensile and flexural strength tests were carried out. Based on the experiments, NS enhances both durability and residual mechanical strength because of low porosity and higher density. [PERSON] and [PERSON] [15] proposed an optimal value of NS to optimize the mechanical properties of concrete. In addition, a high-fitting formula was proposed to forecast the compressive strength of concrete and the optimal SP content. In the numerical simulation process, the contents of cement, water, SP and aggregates, the maximum size of aggregate and curing age were the variables under analysis. It was demonstrated that the proposed formula could accurately predict the optimal value of SP in concrete. [PERSON] et al. [16] published a review article in the area of the influence of SP and waste glass on the mechanical performance of concrete. In addition, a microstructural analysis was employed. [PERSON] and [PERSON] [17] analysed the behaviour of concrete with fly ash, SP and coconut fibres. 15% SP replaced cement and fly ash was employed at four contents by weight: 0%, 5%, 10% and 15%. Besides, 2% of coconut fibres were added to the concrete mixes. The compressive strength, splitting tensile strength, stress-strain relationship, load-deflection and load-time curves of specimens were assessed in this investigation. According to the results, using both coconut fibres and 10% of fly ash significantly improved the mechanical properties of concrete. In 2019, [PERSON] et al. [18] studied the impact of SP on the durability of recycled aggregates SCC. Specimens were manufactured in three families. In the first and second ones, coarse recycled aggregates replaced natural aggregates at four contents: 25%, 50%, 75% and 100%, with and without SP respectively. In the third family, 25% of fine recycled aggregates replaced fine natural aggregates. Both the fresh and hardened state properties of SCC were examined. SP significantly improved the fresh state properties of SCC. Conversely, increasing the recycled aggregates' content resulted in reducing the electric resistivity. SP also controlled the temperature of the solutions used during the test. [PERSON] and [PERSON] [19] examined the impact of perlite powder and SP on the compressive strength and microstructural properties of SCC with a lime-cement binder.