# Impact of Partial Replacement of Cement with a Blend of Marble and Granite Waste Powder on Mortar
## 1 Introduction
Their research demonstrated that the inclusion of granite dust in concrete resulted in an improvement in the average density of concrete as well as early strength of the material. However, the introduction of granite dust in the concrete mixture caused a decrease in water absorption by 32-38% and water penetration by 60-70%. [PERSON] et al. [13] examined the impact of GWP in concrete. They observed that the workability of concrete is influenced by the inclusion of GWP, with higher substitution ratios resulting in more pronounced alterations. The incorporation of 5% GWP led to an increase in the density of concrete. However, when higher substitution ratios were used, the density of concrete decreased. [PERSON] et al. [16] conducted a study to investigate the impact of MWP as a partial replacement for cement on the mechanical performance of mortar. Their findings revealed that substituting cement with marble waste in mortars consistently led to a decrease in mechanical properties. However, even with this reduction, the values remained acceptable for many applications, particularly when the substitution rate was below 25%. In their research, [PERSON] et al. [11] investigated the impact of MWP and GWP on the compressive strength of mortar when used as partial replacements for cement. The study found that MWP did not yield a substantial increase in the compressive strength of cement mortar, in contrast to GWP. The authors also emphasized the importance of further studying the effects of utilizing a combination of MWP and GWP with varying mixing proportions. Although there have been various studies investigating the use of MWP and GWP as partial substitutes for cement, a clear consensus on their impact on concrete or mortar performance is challenging to establish. This is primarily due to the fact that the origin of the marble and granite powder varies, resulting in differing performance outcomes. Some researchers have observed a negative effect on concrete strength when utilizing MWP and GWP, while others have noted positive effects with the appropriate rate of substitution on different properties of concrete and mortar. Moreover, differences in the ingredients used across studies make it difficult to compare the effects of these waste materials as partial substitutes for cement. In addition, most studies have examined the impact of MWP and GWP as partial substitutes for cement in either mortar or concrete separately, with a primary focus on mechanical properties. The primary aim of this research is to explore the effects of blending marble and granite waste powder (MGWP) in varying proportions as a partial substitute for cement in mortar. What sets this study apart from previous research is its comprehensive investigation of the impact of MGWP on multiple properties of mortar when used as a replacement for ordinary Portland cement (OPC). While earlier studies focused on limited factors, this work examines a wide range of parameters including workability, bulk density, compressive strength, homogeneity, surface attack resistance, water absorption, thermal decomposition, and mineralogical composition. Furthermore, this study holds significance and novelty due to the specific region in which it was conducted. As the properties of MWP and GWP are significantly influenced by their origin, no prior research has been undertaken on this specific topic within the region of study. Therefore, the findings of this research provide valuable insights into the potential use of MGWP as a partial replacement for cement in mortar and its impact on various mortar properties.