###### Abstract  
In this paper, the preparation method and reasonable mix ratio of non-calcination brick with rock powder, cement, lime and fly ash eramsite (FAC) as the raw materials were experimentally evaluated. To better understand the effects of each component on the performance of non-calcination rock powder brick (NCRPB), an orthogonal experimental design was conducted with the water-cement ratio (W/C), rock powder-cement ratio (R/C), lime content (w\({}_{\text{I}}\)) and FAC content (w\({}_{\text{I}}\)) as the main factors, which involved four factors and three factor levels. According to the orthogonal experimental design, the compressive strength, water resistance and bulk density of nine groups of NCRPB specimens were tested. The results show that R/C was the most important factor affecting the compressive strength and water resistance, while the FAC content influenced the bulk density of NCRPB greatly. In this study, the reasonable mix of W/C, R/C, w\({}_{\text{I}}\), and w\({}_{\text{I}}\) in weight was 0.6, 3.0, 30% and 21%, respectively. In addition, the microstructure and strength formation mechanism of NCRPB were analyzed by using SEM and XRD. The test results show that the rock powder having pozzolanic activity could react with the additional Ca(OH)\({}_{2}\) to produce hydration products, leading to the improvement of the performance of NCRPB. n _Applied Sci._**2021**, _11_, 10274. [[https://doi.org/10.3390/app112110274](https://doi.org/10.3390/app112110274)]([https://doi.org/10.3390/app112110274](https://doi.org/10.3390/app112110274))  
Academic Editor [PERSON]  
Received: 25 September 2021  
Accepted: 29 October 2021  
Published: 2 November 2021  
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**[PERSON]' Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. **  
land resources. In addition, the bricks do not need to go through high-temperature sintering in the forming process, which reduces energy consumption and carbon dioxide emissions. However, the possible health issues of chemical industrial waste for use as a construction material cannot be ignored [11; 12; 13]. [PERSON] used steel slag, blast furnace slag, fly ash and gypsum to prepare solid waste cementitious materials, and steel slag granular powder was used as an aggregate to prepare steel slag-based eco-unburned permeable bricks. The solid waste utilization rate was 96%, the flexural strength was 4.5 MPa, and the water permeability coefficient was 10.5-10\({}^{-2}\) cm/s [14]. [PERSON] produced non-fired compressed masonry units from brick clay mill residues by alkali activation. The compressive strength, linear shrinkage, bulk density and microstructure were measured, and the effects of curing temperature and curing time on the properties were compared. The results show that the compressive strength of the non-fired brick can reach 24-48 MPa at 28 d [15]. [PERSON] et al. used sludge as a raw material to produce red ceramic tiles by extrusion and investigated the technological changes due to the plasticity of the mixture and its subsequent extrusion properties during the plastic forming process of sludge. The results show that blending 15% sewage sludge by weight into clay mixtures to produce extruded ceramic bricks is very feasible [16]. [PERSON] studied the feasibility of producing unburned brick from sludge produced by coagulation of dye wastewater with Portland cement, Portland cement clinker, alumina cement and slag cement, and the interaction between sludge and cement was analyzed. The results show that the cement-solidified sludge can reach all performance indices of unburned brick, and the compressive strength of alumina-solidified sludge is 40 MPa under a cement/dry sludge/water ratio of 1:0.5-0.8:0.5-0.8 [17]. [PERSON] used mud and calcium sulfoaluminate cement to prepare unburned bricks and tested the influence of the mud content on the performance of unburned bricks.