## 1 Introduction  
Predictions show that a large amount of sand consumption in the future will not only create economic pressure on the construction industry but also cause the erosion and degradation of the world's major ecosystems. The global construction waste crisis will get worse; global waste production will increase by 70% by 2050 in comparison to 2016, and the global waste crisis will spur innovation in waste management. Due to the boom of the construction industry, the price of sand will increase significantly [1]. However, the large amount of construction waste produced by the process of demolition and reconstruction is one of the inevitable additional products in the process of urbanization. Among the construction waste includes a large number of waste concrete blocks, waste clay bricks, waste steel bars, waste wires and cables, waste plastic products, and so on. Among them, clay bricks and concrete blocks account for about 80% of the total [2]. [PERSON] and [PERSON] a system dynamics methodology of the construction and demolition waste management sector by developing a dynamic model that is capable of studying the behavior of landfill process on both the short and long run and its impacts on the environment and economy. In Egypt, this system dynamics methodology results show that the recycling of construction and demolition waste would reduce the costs required to mitigate air pollution by $16,161.35 billion over 20 years [3]. In order to reduce the environmental and economic pressure of construction waste, the reuse of it is an effective method. As for the reuse of construction waste in road engineering, it is usually used for filling roadbeds without secondary crushing, while after secondary crushing, it can be used as aggregate in asphalt pavement and as a cement stabilized base layer [4; 5]. Waste concrete blocks are widely used in road engineering. The superiority of concrete materials for housing construction and considerable secondary hydration are the reasons why waste concrete blocks are widely used among several types of construction wastes. However, due to its high strength, the crushing process is complicated, the requirements for the crushing machine are higher, and the crushing process is difficult. There are also uncontrollable interference factors, such as cement that did not fully hydrate, aggregates from different sources with different strengths, and some waste bricks that cannot be completely removed [6]. In comparison, waste clay bricksare easy to be picked out and crushed and have a lower transportation burden. A stone-crushing machine can be used to crush waste clay bricks, which can save more expenditure. In response to the management of construction waste, many developed countries began to take action to solve the problem in the 1970s and 1980s. Examples include the Solid Waste Treatment Act of 1965 in the United States and the Waste Treatment Act of 1970 in Japan [7]. Many other developed countries, such as Germany, Korea, Denmark, and Singapore also made initial efforts to solve this problem and had momentous success [8; 9]. In China, regulations related to construction waste have been carried out since 1992. The Regulations on the Management of City Appearance and Environmental Hygiene have stipulated that the responsible persons for the disposal of construction waste must take timely clearance and transportation. A series of plans also have been implemented [10]. These actions above are the first step that has been taken in encouraging the recycling of construction waste and governing the unreasonable disposal of construction waste, which laid a foundation for improving the relevant laws and regulations for the recycling and reuse of construction waste. In terms of construction waste recycling, most research studies have focused on cement concrete and asphalt concrete. [PERSON] et al. considered that the optimum amount of construction waste composite powder in cement concrete is 30%.