An internet based intelligent system for early concrete curing in underground structures

Abstract

This paper described a newly developed internet based intelligent early concrete curing system for underground structure construction. The system was composed of field measuring and controlling subsystem (including temperature, humidity and wind speed sensors, solenoid valve, water pump and spray et al.), remote displaying and controlling subsystem (displaying and controlling through PC software or smart phone app) and remote server (data storage and controlling strategy). This system could monitor the wind speed, temperature and humidity condition in field and transfer the data to remote server, which, based on some input parameters, could automatically generate and send the controlling instruction to the field controlling subsystem to control the water pump and spray time. If heat preservation is needed, messages might be sent to the field so that workers would perform the covers maintenance. This system was utilized in a side wall concrete curing project in a station of the Changsha #4 subway, Hunan, China. The inside and surface temperature difference of the concrete is around 3.12 °C. The surface and environmental temperature difference of the concrete is around 9.36 °C. Humidity is maintained at no less than 85%. The site photos shows pitted surfaces and drying shrinkage cracks would appear more easily for concrete under manual work than which under this system. The system could avoid the non-uniformity caused by manual work and also reduce the labor cost.