Research Of Phase Change And Energy Storage Material In Temperature Control Of Hydraulic Concrete

Temperature stress and temperature deformation in hydraulic mass concrete are the main factors which challenging the durability and safety of many concrete structures.Thus,in construction and maintenance of the infrastructure of our country,it is an important task to avoid the generation of temperature crevice in mass concrete.In the process of hydraulic concrete pouring,the heat generated by hydration reaction of cement will gathered inside the structure.Due to the low thermal conductivity of concrete,the heat conduction process is slow and the internal temperature of the structure is higher than the external temperature,then forming a temperature gradient from the inside to outside.The uneven temperature deformation produced uneven temperature and the external constrains result in temperature stress.Phase change & energy storage concrete(PCESC)technology,as a new technology of temperature control in mass concrete,by adding a certain amount of phase change materials(PCMs)into concrete and taking advantage of the heat absorption capacity of PCMs’ solid-liquid and liquid-gas phase change process,to reduce the gradient inside the structure.And it is diffusely used in building construction at present.In order to achieve the purpose of enhancing thermal performance of concrete and not affecting the mechanical properties of concrete,a large number of theoretical and experimental studies are needed to do.The theory,experiment and numerical simulation of PCESC technology are studied in this paper.The main research contents are as follows:1.Based on the theoretical analysis,studying the method for the calculation of adiabatic temperature rise and temperature field in the concrete structure by using the two forms of phase change energy storage materials in the form of phase change sand and phase transition coarse aggregate;2.Optimizing the phase change energy storage materials and carrier materials used in the temperature control of mass hydraulic concrete,and preparing phase change &energy storage aggregates with good shape and good physical properties and chemical properties;3.Using phase change & energy storage aggregates to make PCESC,then measuring the mechanical properties and thermal properties to invent good PCESC;4.Based on the mechanical and thermal parameters of the measured phase-change energy storage concrete,establishing an ANSYS numerical analysis model of mass hydraulic concrete,and simulating the PCESC pouring and curing process,to analyzethe control effect of different phase change aggregates on the temperature field and temperature stress field of mass hydraulic concrete and discuss the application scope of PCESC.