A full-scale study on the thermal emissivity of concrete and application of its findings to verify ANSYS software package

Abstract

Introduction. One of the most popular and complex areas in the design of massive concrete structures is the analysis of their thermal behaviour and thermal stress state. Hence, we can identify tasks related to the phased construction of massive concrete structures, such as gravity dams, massive foundations, bridge supports, etc. A large number of factors, influencing the thermal process, varying over time and depending, among other things, on temperature, determine the complexity of such tasks. The main factor, determining the thermal behaviour of mass concrete in the process of construction, is the exothermic heating of concrete, depending on the type and amount of cement used, as well as several process specifications. Today, such problems can be best solved using the numerical finite element method, implemented in numerous software products. One of them is ANSYS software package, which is widely used to analyze constructions and structures in respect of a full range of actual loadings and impacts. This paper presents the results of the field studies conducted to obtain the initial parameters and verify the precision of results obtained using mathematical modeling techniques of the ANSYS software package. Materials and methods. The authors describe a full-scale experiment that entails the concreting of a concrete testing block. During concrete placing and curing, temperature sensors time tested a temperature change inside the block and in the outside air. Also, studies were conducted using the numerical finite element method employed by the ANSYS software package. Results. The findings of a full-scale experiment were compared with the thermal behaviour analysis made by the ANSYS software package. The comparison has proven highly precise results. The maximum temperature difference at the selected points of the full-scale and numerical models does not exceed 0.6 %. Conclusions. The ANSYS software package solves complex tasks with high accuracy; it determines the thermal behaviour of massive concrete structures, taking into account the thermal emissivity during cement hydration.