Use of pozzolanic materials as an alternative to cement
Use of low-temperature cement
Use of chemical additives to slow the hydrated reactions
Use snow blower
Use of pipes during casting through which the cold water (modern method)
Heat is produced during concrete curing, leading to a temperature rise. Temperatures will eventually return to normal but, in massive concrete, substantial temperature differences may develop during the process between the cooling outer regions and the still hot inner core. This may cause tensile cracking near the outer surfaces.
There are some controls available. One is to limit the thickness of the concrete layers poured, allowing some of the heat to dissipate before pouring the next layer on top; calculations of this type are usually done when designing concrete dams.
A second one is to provide cooling of the inner concrete regions with water circulated through pipes left inside the concrete mass for that purpose.
In any case, note that those types of cracks tend to be of only moderate concern in many practical cases.
Using cold water, slow pouring of concrete , and adding special admixtures may be good techniques.
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Check this http://www.claisse.info/2013%20papers/data/e582.pdf
thanks Joaquin Marti , Muhammed Abbas , Olumoyewa Dotun Atoyebi
Thank you so much for your answers
There are several techniques to tackle this problem, from materials perspective but also from design perspective. You could consider cooling techniques (cooling pipes, liquid nitrogen, cooling individual constituents etc.), adding ggbs in the mix will indeed decrease the peak temperature but not necessarily decrease cracking susceptibility due to its lower the CEM I tensile strain capacity; yet it can be effective, reevaluate pouring sequence, or in the design stage, increase the reinforcement to control cracking or conduct advanced thermo-mechanical analysis of concrete with FEM to get a clearer representation of the expected early age behaviour of the structure.
Controlling temperature in mass concrete sometime makes drastic changes in placed concrete so we have to consider at least following parameters before ordering concrete for site pouring.
- Selection of adequate concrete mix recipe (i.e. ensure using of optimize concrete mix design with Supplementary cementatious material GGBS/Fly Ash/MS and especial additives)
- Lime stone aggregate is the most suitable and ideal aggregate for concrete mix due to its high heat of expansion other than other aggregate types sand stone etc.
- Ensure minimum water to cementious ratio i.e. w/c ration I would prefer to maintain 0. or less
- Ambient temperature should not be high (not more than C)
- Fresh Concrete temperature should not be more than C
- Ensure using of ICE and Chilled water in wet concrete to control the fresh concrete temperature
- Proper quality checks require at site (monitoring quality of concrete at site)
- Proper monitoring of difference in temperature i.e. surface temperature and internal temperature of placed concrete.
- Internal temperature cannot be more than c b/c difference in temperature may cause of cracking or DEF formation in concrete. (DEF process will occur when inner temperature of concrete more than c (measure these temperature with intelirock test equipment)
Use low-heat cement, also you can add anti-shrinkage admixture. In hot countries ice is also added in fresh concrete or some times insert vertical pipe filled with cold water or crushed ice
In bridge abutments, that are massive, in general, no special concrete recipes or care methods are used, but additional reinforcement is designed.
Use of pozzolanic materials as an alternative to cement
Use of low-temperature cement
Use of chemical additives to slow the hydrated reactions
Use snow blower
Use of pipes during casting through which the cold water (modern method)
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