## 1 Introduction  
Aggregates are important resources that account for 60-80% of the volume of concrete, and there is a continuously increasing demand for them. The supply and demand of aggregates, however, has been an important discussion point in the construction industry due to the management and regulation of the collection of natural aggregate for environmental conservation purposes in many countries. To address this supply and demand problem, the concrete industry has made considerable efforts to research and develop new concrete that incorporates recycled or by-product aggregate to replace some of the natural aggregate, while still ensuring the same level of quality (e.g., compressive strength and durability) associated with ordinary concrete that incorporates natural aggregate [1; 2]. As a result of such research, the application of recycled aggregate extracted from waste concrete has been expanded from its use as a roadbed material to being included in major parts of structures [3; 4; 5]. Additionally, studies have actively been conducted to evaluate the performance of slag aggregate, bottom ash aggregate, waste glass aggregate, recycled rubber aggregate, and reclaimed asphalt pavement aggregate, which are recycled and by-product aggregates [6; 7; 8; 9; 10; 11]. [PERSON] et al. [6] examined the durability of concrete mixed with recycled aggregate, examining properties such as impermeability, chloride penetration resistance, carbonation resistance, frost resistance, and the alkali-silica reaction. They concluded that the durability of recycled aggregate concrete is mainly affected by the adhered mortar of recycled aggregate, and incorporation of a mineral admixture or using recycled aggregate originating from higher-strength concrete can minimize the durability problem in recycled aggregate concrete. [PERSON] et al. [7] evaluated various mechanical properties of concrete mixed with carbonated recycled concrete aggregate (RCA), and drew the replacement percentage of natural aggregates by the carbonated RCAs can be increased to 60% with an insignificant reduction in the mechanical properties of the new concrete. [PERSON] et al. [8] proposed an eco-friendly method with acetic acid solution of improving the quality of recycled aggregate, and showed the RCAs can enhance the compressive strength of the concrete at 28 days up to 25%. [PERSON] et al. [9] conducted research on the utilization of high-performance concrete of 60 MPa in which recycled aggregate was used as both fine and coarse aggregate. [PERSON] et al. [10] evaluated the mechanical strength and durability of concrete mixed with slag and natural aggregates, and they found that steel slag replacement increases the connected porosity and the water permeability, and improves the carbonation resistance and abrasion resistance. [PERSON] et al. [11] examined various physical properties of concrete that incorporated bottom ash as a fine aggregate, and found low quantity of coal bottom ash has the potential to replace the fine aggregates without compromising the performance of the concretes. [PERSON] et al. [12] conducted an experimental study in which they assessed the hazards and mechanical properties associated with concrete that incorporated bottom ash as a coarse aggregate. They obtained a result that the soundness and resistance to abrasion of coal bottom ash coarse aggregate were satisfied according to the standard of coarse aggregate for concrete. The result of the leaching test for coal bottom ash coarse aggregate and porous concrete produced with these coarse aggregates, it was satisfied with the environmental criteria. In addition, studies related to various recycled and by-product aggregates have actively been conducted [13; 14; 15]. These previous studies are significant in that they inspired technologies that enabled the incorporation of recycled and by-product aggregates into concrete through the analysis of their physical properties.