A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Curing of Structual Concrete with Infrared Radiant Heat
This report shows how the measures necessary for the curing of structural concrete, in order that the intended strength may be achieved within the specified time, can be determined by means of computer calculations. In these calculations, the effect of e.g. different types of formwork or thermal insulation, the time of formwork is struck, application and removal of thermal insulation, and varying degrees of heating, can be studied. On the basis of the above, the combination of measures which meets the specified strength requirements as a given age and which produces the lowest cost for each particular pour, can be selected. This method is an alternative to the selection of measures 'by feel' or 'on the basis of experience' or by using collections of diagrams. However, the results are only as reliable as the input data selected for the calculations. Examples of factors of uncertainty are assumptions regarding outdoor temperature and wind velocity. With particular reference to radiant heating, the efficiencies of liquefied gas and electric radiant heaters are analyzed, and the absorption capacity of formwork material and concrete are investigated. Development of temperature in concrete floors is simulated for different climatic, insulation and heating conditions. The calculated temperature development and concrete strength are compared with the results of field studies made during winter pours of concrete floors in the course of normal production. Reduction of strength due to heat curing and deflections of concrete floors due to early striking of formwork are discussed and countermeasures are proposed. With 28 refs. (ERA citation 13:036923)
Curing of Structual Concrete with Infrared Radiant Heat
This report shows how the measures necessary for the curing of structural concrete, in order that the intended strength may be achieved within the specified time, can be determined by means of computer calculations. In these calculations, the effect of e.g. different types of formwork or thermal insulation, the time of formwork is struck, application and removal of thermal insulation, and varying degrees of heating, can be studied. On the basis of the above, the combination of measures which meets the specified strength requirements as a given age and which produces the lowest cost for each particular pour, can be selected. This method is an alternative to the selection of measures 'by feel' or 'on the basis of experience' or by using collections of diagrams. However, the results are only as reliable as the input data selected for the calculations. Examples of factors of uncertainty are assumptions regarding outdoor temperature and wind velocity. With particular reference to radiant heating, the efficiencies of liquefied gas and electric radiant heaters are analyzed, and the absorption capacity of formwork material and concrete are investigated. Development of temperature in concrete floors is simulated for different climatic, insulation and heating conditions. The calculated temperature development and concrete strength are compared with the results of field studies made during winter pours of concrete floors in the course of normal production. Reduction of strength due to heat curing and deflections of concrete floors due to early striking of formwork are discussed and countermeasures are proposed. With 28 refs. (ERA citation 13:036923)
Curing of Structual Concrete with Infrared Radiant Heat
J. Nilsson (author)
1986
76 pages
Report
No indication
English