# Optimization Algorithm for Cutting Masonry with a Roboti Saw
## 1 Introduction  
Global efforts to reduce the consumption of raw materials obtained from non-renewable sources also apply to the materials used in the building industry [1, 2]. Generally, the building industry is responsible for around 30-50% of the waste production in developed countries [3, 4, 5]. It is therefore necessary to advance strategies to reduce the quantity of construction and demolition waste (CDW). Furthermore, the price of building materials has increased by an average of 35-50% over the last decade, so there is also a need to develop operations supporting cost efficiency in construction processes, namely, throughimproved material handling [6; 7; 8]. Fired clay bricks (FCBs) are a dominant building material worldwide due to their low cost and ease of production, as shown by [PERSON] [9]. One of the most promising strategies to address environmental and economic challenges in the building industry is the digitization of building life cycles [10; 11; 12]. On construction sites, digitization is introduced by the utilization of robots, which is why robotic construction technologies have developed very rapidly in the last decade [13; 14; 15]. In the current construction industry, ceramic brick walls are laid using standardized brick blocks. The dimension of these blocks is based on the module given by the manufacturer. The most common module is 250 mm, 375 mm or 500 mm [16; 17]. Brick manufacturers offer additional types of blocks for each module. This allows the walls to be connected while keeping the module intact. No extra cutting of the blocks is needed on-site. These extra blocks are usually half blocks, end blocks and corner blocks [18]. If the walls of a building are not designed with respect to the module of the brick block, it is necessary to insert custom brick sections made by cutting modular brick blocks into pieces as a supplement to the modular blocks. The production of these offcuts reduces process efficiency and generates pieces that, in many cases, cannot be further used due to their size and end up as CDW. The utilization of robots in the field of bricklaying holds considerable potential for enhancing the efficiency and safety of wall construction. The existing reference studies have primarily focused on the optimization of the bricklaying process itself, with a focus on the optimization time, cost and energy savings [19]. However, the integration of robotic saws into the robotic process is crucial for the construction of walls involving non-standard block cutoffs. To the best of our knowledge, no reference study has hitherto been found that focuses on the optimization of the bricklaying process with the aim of reducing the number of cutoffs and wear of a robotic saw. Also, no reference study has been found that describes the use of bin packing algorithms in the bricklaying process to optimise the use of bricks. The development of a novel methodology to address the optimization of robotic brick cutting, with the objective of reducing the consumption of bricks and reducing the rate of wear of the robotic saw, would enhance the efficiency of robotic bricklaying and facilitate the dissemination of this technology to construction sites. A promising potential to reduce CDW lies in the optimization algorithms that can be effectively implemented in construction processes focused on on-site material handling. The research paper presented here describes a mathematical model determining an optimal masonry cutting plan used as an input for the operation of a robotic saw. The newly developed packing algorithm that optimizes masonry cutting and the operations of a robotic saw can determine an enhanced plan of masonry cuts and the number of necessary operations in the entire laying plan [19] of the Building Information Model (BIM). The employment of packing algorithms in the field of robotic bricklaying was previously restricted to the optimization of brick packing in order to completely fill the designed walls.