The slag cement used in mass concrete allowed for higher strength gains and reduced peak heat of hydration
BELITIC CSA CEMENTS Cement type Alite, Belite [C.sub.3]S (%) [C.sub.2]S (%) Type I portland 59 15 General purpose Type II portland 46 29 Moderate sulfate resistance Type III portland 60 12 High early strength Type IV portland 30 46 Low heat of hydration
Type V portland 43 36 High sulfate resistance Belitic CSA 0 45 Rapid Set Cement Cement type Celite Calcium sulfoaluminate [C.sub.3]A (%) [C.sub.4][S.sub.3]A (%) Type I portland 12 0 General purpose Type II portland 6-8 0 Moderate sulfate resistance Type III portland 12-15 0 High early strength Type IV portland 5-7 0 Low heat of hydration
Type V portland 4-5 0 High sulfate resistance Belitic CSA 0 25 Rapid Set Cement Alite or tricalcium silicate is responsible for early strength and begins hydrating at around 24 hours.
Heat of Hydration
. The heat production is described by the approach based on the hydration degree (equivalent to maturity age) :
Heat of Hydration
. The hydration heat of composite cementitious materials was tested by using ToniTechnik7338 Isothermal Differential Calorimeter.
Both the aluminate and the ferrite phase contribute to the heat of hydration
and affect the rheology of the setting concrete.
Abstract: Heat of hydration
up to 72 hours and compressive strength up to 7 days of Portland cement and 17 binary and ternary cements containing fly ash, silica fume, and metakaolin, at a water/cement ratio of 0.50 and addition contents of 20%, 35%, and 55%, were used to examine the early-age performance of concrete.
Wang, "Influence of cement fineness and water-to-cement ratio on mortar early-age heat of hydration
and set times," Construction and Building Materials, vol.
in their paper "Feasibility of using PCM to control the heat of hydration
in Massive Concrete Structures" The Scientific World Journal.
The quantity of heat developed upon complete hydration of a certain amount of unhydrated cement at a given temperature is defined as heat of hydration
"This heat of hydration
is a much greater problem for Freedom Tower's thick core walls, categorized as Mass Concrete, than for the conventional concrete walls outside the core," said Eilon.
"Each mix design of thermal grout is different and is based on several requirements: thermal conductivity, flow (time of efflux), strength, rate of hardening and heat of hydration
." said Parmar.