# Performance of Concrete with Waste Granite Powder: The Effect of Superplasticizers
## 1 Introduction
In this research, the effect of the granite powder on the mechanical characteristics, corrosion resistance and hydration products was investigated: an improvement in concrete corrosion cracking time and mechanical characteristics for 5.0% replacement was seen, and no significant changes were reported in microstructure, degree of hydration and hydration products from using granite powder. [PERSON] et al. [10] reported that high-strength coloured mortar can be prepared from stone waste. According to this research, reddish pigments can be obtained by calcination of granite waste at 700-900 \({}^{\circ}\)C for a short time, which can be used in the production of coloured concrete, due to Fe\({}_{2}\)O\({}_{3}\) crystallizing during the after heating treatment, with acceptable compressive strength (\(f_{\rm cm}\)). A number of researches have shown that the incorporation of several types of stone waste in concrete production  
Figure 1: Stone production of different countries/regions (%) [5]. results in lower slump of fresh concrete in comparison with traditional concrete, and increasing the waste content further lowers the slump. It is argued that the particle size of the stone aggregates is the reason behind this lower slump [5]. More recently, researchers have produced concrete with granite waste as cement replacement with a focus on pozzolanic activity, durability and higher substitution ratios. [PERSON] et al. [11], in 2017, evaluated the performance of a new blended cement incorporating 10% or 20% granite sludge as clinker replacement, analyzing the chemical, rheological, mechanical and microstructural properties of the end product. They found that granite sludge as partial cement replacement can shorten the initial time setting depending on the substitution ratio, with higher ratios resulting in less effect on the setting time. More interestingly, the new developed blended cement showed slight changes in hydration products and morphology. [PERSON] et al. [12], in 2018, studied the properties of mortar and concrete incorporating granite sludge as cement replacement with various substitution ratios from 0 to 40%. The results of this study clearly highlight the potential effects of granite sludge on an enhanced durability of concrete including abrasion, freeze and thaw cycles and sulfate attack resistance. In addition, they concluded that granite sludge may be effectively used in concrete bricks, paving units, and cement tiles' production. An enhanced durability of concrete incorporating granite sludge was also demonstrated in the study conducted by [PERSON] et al. [13], in 2018, with aesthetically sensitive applications. [PERSON] et al. [14], in 2018, investigated the microstructural characteristics of paste produced with ornamental stone processing waste after heat treatment showing low pozzolanic activity, resulting in a denser final product due to the filler effect and a probable small pozzolanic reaction. Nowadays, admixtures and additions are indispensable components of concrete. In recent years, some researchers studied the simultaneous effects of superplasticizers (SP) and different waste materials on concrete [15; 16; 17; 18]. Most of them reported that using SP, by decreasing the water to cement ratio (w/c) and better dispersing the cement particles, can overcome the disadvantages due to the use of waste. [PERSON] et al. [16], for instance, reported a higher compressive strength of concrete incorporating recycled aggregates and superplasticizers than that of the same concrete mix with no admixtures, while [PERSON] et al. [19] concluded that superplasticizers are more effective on the shrinkage and durability properties of concrete produced with construction and demolition waste aggregates than that with concrete recycled aggregates. According to them, in some cases of chloride ingress, superplasticizers could not effectively improve the performance of concrete made with construction and demolition waste aggregates.