## 1 Introduction  
With the continuous development of the construction industry, cement production has grown dramatically, resulting in increasingly aggravated carbon emissions and environmental pollution [1]. The main sources of carbon emissions in cement production are the chemical reaction of clinker components and the combustion of fossil fuels [2]. Based on the above two points, it is estimated that the total emissions from the cement industry are about 8% of global carbon emissions [3]. The partial replacement of cement with low-energy industrial and agricultural solid waste can reverse the rising carbon emissions trend, thus achieving energy efficiency and environmental protection [4; 5; 6]. Although using industrial solid wastes such as silica fume (SF), fly ash (FA) and ground granulated blast furnace slag (GGBPS) in concrete has the potential to reduce carbon dioxide emissions and contribute to the idea of sustainable development in the cement sector, their sources are limited by geographical conditions, technological conditions and economic costs [7; 8]. Therefore, using agricultural solid wastes such as rice husk ash (RHA) in concrete has aroused extensive interest [9; 10]. The rice husk is a broad source of agricultural waste collected during the grinding process from the surface layer of rice grains. In the field of green technology, rice husks are mainly used as fuel for processing rice grains, as boiler steam or as fuel for producingelectricity in biomass power plants [11; 12]. RHA is an agricultural residue generated by the incineration of rice husk [13]. Because of its high amorphous silica concentration, specific surface area and pozzolanic activity, it is regarded by many researchers as a cementitious material for increasing the properties of concrete [14; 15; 16]. Recycled concrete aggregate is an environmentally friendly material prepared from construction and demolition waste (CDW) by sorting, crushing, sieving and cleaning, which can be used in the construction sector to alleviate the gradually decreasing natural aggregate and solve the problem of the piling and disposal of construction solid waste, which is conducive to sustainable development [17; 18]. Currently, the use of supplementary cementitious materials and recycled concrete aggregate for concrete preparation in the construction industry has attracted widespread attention. Therefore, many researchers have studied the mechanical characteristics and durability of concrete prepared synergistically from RHA and recycled aggregate. [PERSON] et al. [19] studied the coupling effect of hook-ended steel fibers (HSF) and 15% RHA on the mechanical properties and durability of RAC. The results revealed that the joint action of RHA and fibers significantly enhanced the compressive strength, splitting tensile strength, impermeability and acid attack resistance (AAR) of RAC. [PERSON] et al. [20] evaluated recycled concrete's mechanical properties, chloride penetration depth and steel corrosion using ground RHA. The findings revealed that using RHA had adversely affected the compressive strength of RAC, while greatly improving steel corrosion and chloride resistance. [PERSON] et al. [5] studied the effect of waste mineral admixtures and glass fibers on the mechanical and permeability properties of recycled aggregate concrete. The results showed that the combined action of RHA and glass fibers resulted in recycled aggregate concrete exhibiting improved mechanical and durability properties compared to natural aggregate concrete. [PERSON] et al. [21] investigated the influence of RHA replacing silica nanoparticles on the mechanical and fire resistance properties of recycled concrete. The results showed that the addition of rice husk ash could lead to enhanced mechanical properties of recycled concrete by improving the microstructure of the paste, but RHA will adversely affect the post-fire residual strength of recycled concrete. [PERSON] et al. [22] investigated the engineering application effect of 0-35% RHA and recycled aggregate to prepare concrete.