Construction safety is a key factor among the many factors related to the sustainable management of construction sites. Although research is underway to reduce potential accidents in the construction industry in Korea, the number of tower crane (T/C) accidents is consistently increasing based on the increased use of such cranes. In this study, the priorities of accident causes for each T/C type were derived and utilized for the sustainable management of construction sites. An analytic hierarchy process (AHP) questionnaire was completed by experts such as construction engineers, construction managers, safety engineers, and T/C operators with more than ten years of field experience. The results of the AHP questionnaire revealed that the leading cause of cab-control T/C accidents is poor operator visibility, while the leading cause of accidents related to remote-control T/Cs is the poor management of lifting objects and control of surroundings. The high-ranking causes derived in this study should be managed and priority measures should be implemented to reduce the number of T/C accidents.

As interest in smart construction technology increases, various smart construction technologies are being used for sustainable construction management. Among these technologies, 3D laser scanning technology stands out for phenomena analysis and monitoring, with various applications being studied for construction management. This study aimed to identify structural members from point cloud data (PCD) obtained through 3D laser scanning and utilize them for the measurement of work progress in construction projects. The method for identifying members is to obtain location coordinate data from the BIM (Building Information Modeling) model of the project and identify the structural member in the PCD by comparing them with the member’s location coordinates from the PCD obtained with a 3D laser scanner. In this study, members such as columns, beams, girders, walls, and slabs among the structural members constructed at construction sites were identified through this process. For identified structural members completed at the actual construction site, the unit price and quantity were taken from the construction project’s bill of quantity (BOQ) database, and then the Earned Value (EV) was calculated. The results of the study suggest that the progress measurement process through BIM and 3D laser scanning, which was previously performed manually, can contribute to faster and more accurate work progress measurement. Ultimately, it is expected that efficient process management will be possible, contributing to the realization of sustainable construction management.

Although accurately estimating the early age compressive strength of concrete is essential for the timely removal of formwork and the advancement of construction processes, it is challenging to estimate it in cool, cold, hot, or unmanaged conditions. Various nondestructive testing methods, including recent IoT-based techniques, have been proposed to determine the compressive strength of concrete. This study evaluates the maturity method using the wireless thermocouple sensor in assessing the early age compressive strength of concrete slabs, particularly those not subjected to watering and protection in a cool environment below 20 °C. For this purpose, wire and wireless thermocouple sensors were installed in reinforced concrete (RC) slabs, whereas wire thermocouple sensors were installed in concrete cylinders. In addition, the compressive strengths of standard-cured cylinders, field-cured cylinders, and core samples extracted from the RC slab were measured. On day 7, the maturity index (M) values for the field-cured cylinders were 7% lower than those of the standard-cured cylinders, and the M values for the RC slabs with wire and wireless sensors were 6% lower. The compressive strengths of the field-cured cylinders and core samples extracted from the RC slabs were 19% and 14% lower than those of the standard-cured cylinders, respectively. Thus, while the difference in M values was 6–7%, the difference in compressive strength was significantly higher, at 14–19%. In a cool environment without watering or protection, the difference in strength can be even greater. Consequently, a commercial IoT-based thermocouple sensor can replace conventional wire sensors and adopt to estimate early age compressive strength of concrete in unmanaged curing condition.